Water-Cooled Scroll Compressor Chillers

Installation, and Maintenance Manual IMM WGZ-2

Group: Chiller Part Number: 331374401 Effective: October 2005 Supercedes: IOMM WGZ-1

Water-Cooled Scroll Compressor Chillers

WGZ 030AW To WGZ 120AW, Packaged Water-Cooled Chiller

WGZ 030AA To WGZ 120AA, Chiller with Remote Condenser

30 to 120 Tons, 105 to 420 kW 60 Hz, R-22

2 WGZ 030A through 120A IMM WGZ-2

Table of Contents

Introduction........................................3 General Description............................... 3 Nomenclature ........................................ 3 Inspection .............................................. 3

Installation..........................................4 Vibration Isolators ................................. 6

Water Piping.....................................10 Flow Switch......................................... 13 Glycol Solutions.................................. 13 Condenser Water Piping...................... 14 Minimum Flow Rates .......................... 15 Water Pressure Drop............................ 16

Refrigerant Piping ...........................18 Unit with Remote Condenser .............. 18 Factory-Mounted Condenser............... 22

Dimensional Data.............................23 Physical Data....................................27

AW Water-Cooled................................ 27 AA Remote Condenser ........................ 30 Operating Limits.................................. 31 Components......................................... 32

Wiring ...............................................33 Unit Configuration ..........................34 Electrical Data..................................35

Field Wiring Diagram.......................... 41 Control Panel Layout .......................... 44 Motor Protection Module.................... 44

Start-Up and Shutdown .................. 45 Pre Start-up.......................................... 45 Start-up ................................................ 45 Weekend or Temporary Shutdown ...... 46 Start-up after Temporary Shutdown .... 46 Extended Shutdown............................. 46 Start-up after Extended Shutdown ...... 47

System Maintenance........................ 48 General ................................................ 48 Electrical Terminals............................. 49 Compressor Lubrication...................... 49 Sight glass and Moisture Indicator...... 49 Crankcase Heaters ............................... 50 Optional Controls ................................ 50 Phase/Voltage Monitor (Optional) ...... 50 Hot Gas Bypass (Optional) ................. 51

Maintenance Schedule .................... 52 System Service ................................. 53

Troubleshooting Chart......................... 55 Warranty Statement ........................ 56

"McQuay" is a registered trademark of McQuay International ©2005 McQuay International

Illustrations and data cover McQuay International products at the time of publication and we reserve the right to make changes in design and construction at anytime without notice.

Manufactured in an ISO Certified facility

IMM WGZ-2 WGZ 030A through 120A 3

Introduction

General Description McQuay Type WGZ water chillers are designed for indoor installations and are available with water-cooled condensers (Model AW), or arranged for use with remote air-cooled or evaporative condensers (Model AA). Each water-cooled unit is completely assembled and factory wired before evacuation, charging and testing. They consist of hermetic scroll compressors, brazed-plate evaporator, water-cooled condenser (WGZ-AW), and complete refrigerant piping.

Units manufactured for use with remote condensers (Models WGZ-AA) have all refrigerant specialties factory-mounted and connection points for refrigerant discharge and liquid lines.

Liquid line components that are included are manual liquid line shutoff valves, charging valves, filter-driers, liquid line solenoid valves, sight glass/moisture indicators, and thermal expansion valves.

Other features include compressor crankcase heaters, and a MicroTech II� microprocessor controller.

The electrical control center includes all equipment protection and operating controls necessary for dependable automatic operation.

The compressors are not fused as standard, but can be protected by optional circuit breakers or fuses, or can rely on a field-installed, fused disconnect switch for protection.

Nomenclature

W G Z 100 - A W

Inspection When the equipment is received, all items should be carefully checked against the bill of lading to be sure of a complete shipment. All units must be carefully inspected for damage upon arrival. All shipping damage must be reported to the carrier and a claim must be filed with the carrier. The unit serial plate should be checked before unloading the unit to be sure that it agrees with the power supply available. Physical damage to unit after acceptance is not the responsibility of McQuay.

Note: Unit shipping and operating weights are given in the physical data tables beginning on page 27.

Water-Cooled

Global

Scroll Compressor Nominal Capacity (Tons)

W = Water-Cooled CondenserA = Unit Less Condenser

Design Vintage


RemovableLiftingBar

(2) 2”LiftingHoles

Installation

Note: Installation and maintenance are to be performed only by qualified personnel who are familiar with local codes and regulations, and experienced with this type of equipment.

WARNING Avoid contact with sharp edges. Personal injury can result.

Handling Every model WGZ-AW water chiller with water-cooled condensers is shipped with a full refrigerant charge. For shipment, the charge is contained in the condenser and is isolated by the condenser liquid shutoff valve and the compressor discharge valve common to a pair of compressors.

A holding charge is supplied in remote condenser models, WGZ-AA. The operating charge must be field supplied and charged.

WARNING If the unit has been damaged, allowing the refrigerant to escape, there can be danger of suffocation in the area since the refrigerant will displace the air. Be sure to review Environmental Protection Agency (EPA) requirements if damage

occurred. Avoid exposing an open flame to the refrigerant.

Moving the Unit Shipping skids are an option and if not supplied, some means such as dollies or skids must be field furnished to protect the unit from accidental damage and to permit easy handling and moving.

Figure 1, Lifting the Unit

It is recommended that all moving and handling be performed with skids or dollies under the unit when possible and that they not be removed until the unit is in the final location.


Never put the weight of the unit against the control box.

In moving, always apply pressure to the base on the skids only and not to the piping or other components. A long bar will help move the unit easily. Avoid dropping the unit at the end of the roll.

If the unit must be hoisted, lift the unit from the removable lifting arms factory-bolted to each end of the unit adjacent to the tube sheet by attaching cables or chains to the end of the arms. A spreader bar must be used to protect the piping, control panel and other areas of the chiller (see Figure 1). The arms should be removed and discarded after use. Do not attach slings to piping or equipment. Do not attempt to lift the unit by lifting points mounted on the compressors. They are for lifting only the compressor should one need to be removed from the unit. Move unit in the upright horizontal position at all times. Set unit down gently when lowering from the truck or rollers.

Table 1, Lifting Loads Package Units (lbs. Less Condenser Units (lbs)

Model L1 L2 L3 L4 Shipping

Weight L1 L2 L3 L4 Shipping Weight

WGZ 030 564 616 655 715 2551 469 502 562 601 2134 WGZ 035 572 626 672 736 2606 473 507 576 617 2172 WGZ 040 584 641 695 764 2684 477 514 592 637 2219 WGZ 045 596 658 717 792 2763 486 525 610 659 2281 WGZ 050 604 668 739 817 2828 487 527 625 676 2315 WGZ 055 646 719 761 846 2973 526 577 643 705 2452 WGZ 060 800 892 855 953 3500 620 673 675 733 2701 WGZ 070 863 966 890 996 3716 673 735 700 764 2871 WGZ 080 900 1009 961 1077 3947 702 769 763 837 3071 WGZ 090 908 1021 1019 1145 4094 700 769 812 892 3172 WGZ 100 916 1031 1059 1191 4197 696 771 841 931 3238 WGZ 110 931 1046 1067 1196 4240 706 781 846 936 3268 WGZ 120 937 1050 1077 1211 4275 706 781 861 951 3298

Location WGZ chillers are designed for indoor application and must be located in an area where the surrounding ambient temperature is 40°F (4°C) or above. A good rule of thumb is to place units where ambient temperatures are at least 5°F (3°C) above the leaving water temperature. Because of the electrical control devices, the units should not be exposed to the weather. A plastic cover over the control box is supplied as temporary protection during shipment. A reasonably level and sufficiently strong floor is required for the water chiller. If necessary, additional structural members should be provided to transfer the weight of the unit to the nearest beams.

Note: Unit shipping and operating weights are given in Table 1 and in the physical data tables beginning on page 27.

Space Requirements for Connections and Servicing The chilled water and condenser water (on units with a water-cooled condenser) piping enters and leaves the unit from the right side when looking at the control panel. Left-hand condenser connections are an option. A clearance of at least 3 feet (1219 mm), or more if codes require, should be provided beyond this piping and on all other sides and ends of the unit for general servicing or for changing the compressors, if it ever becomes necessary.


Control Panel

WaterConnections

4

1

3

2

LB

LF

RB

FRF

On units equipped with a water-cooled condenser (Type WGZ-AW) clearance should also be provided for cleaning or removal of condenser tubes on one end of the unit. The clearance for cleaning depends on the type of apparatus used, but can be as much as the length of the condenser (10 feet, 3050 mm). Tube replacement requires the tube length of 10 feet (3050 mm) plus one to two feet of workspace. This space can often be provided through a doorway or other aperture. Allow a minimum of 4-foot clearance in front of the control panel.

Placing the Unit The small amount of vibration normally encountered with the water chiller makes this unit particularly desirable for basement or ground floor installations where the unit can be mounted directly to the floor. The floor construction should be such that the unit will not affect the building structure, or transmit noise and vibration into the structure.

Vibration Isolators It is recommended that isolators be used on all upper level installations or in areas where vibration transmission is a consideration.

Figure 2, Isolator Locations Transfer the unit as indicated under “Moving the Unit.” In all cases, set the unit in place and level with a spirit level. When spring-type isolators are required, install springs running under the main unit supports.

The unit should be set initially on shims or blocks at the listed spring free height. When all piping, wiring,

flushing, charging, etc., is completed, the springs are adjusted upward to loosen the blocks or shims that are then removed. A rubber anti-skid pad should be used under isolators if hold-down bolts are not used. Installation of spring isolators requires flexible piping connections and at least three feet of flexible electrical conduit to avoid straining the piping and transmitting vibration and noise.

Table 2, Weights & Vibration Mountings ARRANGEMENT WGZ-AW, WITH WATER-COOLED CONDENSERS

Corner Weight Lbs (kg) Neoprene-In-Shear Mountings Spring-Flex Mountings Unit Size

Opr. Wt. Lbs. (kg) 1 2 3 4 1 2 3 4 1 2 3 4

030 2692 (1219)

589 (267)

648 (294)

692 (314)

762 (345)

RP-3 Green

RP-3 Green

RP-3 Green

RP-3 Gray

CP-1 Green

CP-1 Green

CP-1 Green

CP-1 Green

035 2760 (1250)

599 (271)

661 (299)

713 (323)

787 (356)

RP-3 Green

RP-3 Green

RP-3 Green

RP-3 Gray

CP-1 Green

CP-1 Green

CP-1 Green

CP-1 Green

040 2866 (1298)

616 (279)

682 (309)

744 (337)

824 (373)

RP-3 Gray

RP-3 Gray

RP-3 Gray

RP-3 Gray

CP-1 Gray

CP-1 Gray

CP-1 Gray

CP-1 Gray

045 2966 (1344)

632 (286)

702 (318)

773 (350)

860 (389)

RP-3 Gray

RP-3 Gray

RP-3 Gray

RP-3 Gray

CP-1 Gray

CP-1 Gray

CP-1 Gray

CP-1 Gray

050 3058 (1385)

644 (292)

718 (325)

802 (363)

894 (405)

RP-3 Gray

RP-3 Gray

RP-3 Gray

RP-3 Gray

CP-1 Gray

CP-1 Gray

CP-1 Gray

CP-1 Gray

055 3213 (1455)

688 (312)

772 (350)

826 (374)

927 (420)

RP-3 Gray

RP-3 Gray

RP-3 Gray

RP-3 Gray

CP-1 Gray

CP-1 Gray

CP-1 Gray

CP-1 Gray

060 3809 (1725)

853 (386)

959 (435)

940 (426)

1057 (479)

RP-4 Black

RP-4 Black

RP-4 Black

RP-4 Black

CP-1 White

CP-1 White

CP-1 White

CP-1 White

Continued next page


Corner Weight Lbs (kg) Neoprene-In-Shear Mountings Spring-Flex Mountings Unit

Size Opr. Wt. Lbs. (kg) 1 2 3 4 1 2 3 4 1 2 3 4

070 4025 (1823)

916 (415)

1033 (468)

975 (442)

1100 (498)

RP-4 Black

RP-4 Black

RP-4 Black

RP-4 Black

CP-1 White

CP-1 White

CP-1 White

CP-1 White

080 4289 (1943)

958 (434)

1082 (490)

1056 (478)

1193 (540)

RP-4 Black

RP-4 Black

RP-4 Black

RP-4 Black

CP-2 Green

CP-2 Green

CP-2 Green

CP-2 Green

090 4484 (2031)

974 (441)

1103 (500)

1129 (511)

1278 (579)

RP-4 Black

RP-4 Black

RP-4 Black

RP-4 Black

CP-2 Green

CP-2 Green

CP-2 Green

CP-2 Green

100 4627 (2096)

989 (448)

1121 (508)

1170 (534)

1337 (606)

RP-4 Black

RP-4 Black

RP-4 Black

RP-4 Black

CP-2 Green

CP-2 Green

CP-2 Green

CP-2 Green

110 4670 (2120)

1010 (459)

1140 (518)

1178 (535)

1342 (609)

RP-4 Black

RP-4 Black

RP-4 Black

RP-4 Black

CP-2 Green

CP-2 Green

CP-2 Green

CP-2 Green

120 4705 (2136)

1015 (461)

1145 (520)

1195 (543)

1350 (613)

RP-4 Black

RP-4 Black

RP-4 Black

RP-4 Black

CP-2 Green

CP-2 Green

CP-2 Green

CP-2 Green

ARRANGEMENT WGZ-AA, FOR REMOTE CONDENSER

Corner Weight Lbs (kg) Neoprene-In-Shear Mountings Spring-Flex Mountings Unit Size

Opr. Wt. Lbs. (kg) 1 2 3 4 1 2 3 4 1 2 3 4

030 2162 (979)

468 (212)

502 (227)

575 (260)

616 (279)

RP-3 Green

RP-3 Green

RP-3 Green

RP-3 Green

CP-1 Purple

CP-1 Purple

CP-1 Orange

CP-1 Orange

035 2204 (998)

472 (214)

507 (230)

590 (267)

634 (287)

RP-3 Green

RP-3 Green

RP-3 Green

RP-3 Green

CP-1 Purple

CP-1 Purple

CP-1 Orange

CP-1 Orange

040 2257 (1022)

477 (216)

514 (233)

609 (276)

657 (297)

RP-3 Green

RP-3 Green

RP-3 Green

RP-3 Green

CP-1 Purple

CP-1 Purple

CP-1 Orange

CP-1 Orange

045 2329 (1055)

487 (220)

526 (238)

633 (287)

684 (310)

RP-3 Green

RP-3 Green

RP-3 Green

RP-3 Green

CP-1 Purple

CP-1 Purple

CP-1 Orange

CP-1 Orange

050 2370 (1074)

488 (221)

528 (239)

650 (295)

704 (319)

RP-3 Green

RP-3 Green

RP-3 Green

RP-3 Green

CP-1 Purple

CP-1 Purple

CP-1 Orange

CP-1 Orange

055 2505 (1135)

526 (238)

578 (262)

668 (303)

734 (332)

RP-3 Green

RP-3 Green

RP-3 Green

RP-3 Green

CP-1 Purple

CP-1 Purple

CP-1 Orange

CP-1 Orange

060 2771 (1255)

619 (280)

674 (305)

707 (320)

770 (349)

RP-3 Green

RP-3 Green

RP-3 Gray

RP-3 Gray

CP-1 Orange

CP-1 Orange

CP-1 Green

CP-1 Green

070 2942 (1333)

672 (304)

736 (333)

732 (332)

801 (363)

RP-3 Green

RP-3 Green

RP-3 Gray

RP-3 Gray

CP-1 Orange

CP-1 Orange

CP-1 Green

CP-1 Green

080 3154 (1429)

702 (318)

771 (349)

801 (363)

880 (399)

RP-3 Green

RP-3 Gray

RP-3 Gray

RP-3 Gray

CP-1 Orange

CP-1 Green

CP-1 Green

CP-1 Gray

090 3271 (1482)

700 (317)

771 (349)

857 (388)

944 (427)

RP-3 Green

RP-3 Gray

RP-3 Gray

RP-3 Gray

CP-1 Orange

CP-1 Green

CP-1 Green

CP-1 Gray

100 3346 (1516)

697 (316)

773 (350)

890 (403)

987 (447)

RP-3 Green

RP-3 Gray

RP-3 Gray

RP-3 Gray

CP-1 Orange

CP-1 Green

CP-1 Green

CP-1 Gray

110 3375 (1532)

707 (320)

783 (355)

895 (406)

990 (449)

RP-3 Green

RP-3 Gray

RP-3 Gray

RP-3 Gray

CP-2 Green

CP-2 Green

CP-2 Green

CP-2 Green

120 3405 (1546)

707 320)

783 (355)

910 (413)

1005 (456)

RP-3 Green

RP-3 Gray

RP-3 Gray

RP-3 Gray

CP-2 Green

CP-2 Green

CP-2 Green

CP-2 Green


Table 3, Spring Flex Isolators Dimensions

In. (mm) Housing Spring Color

Max. Load Each

Lbs. (kg)

Defl. In. (mm)

A B C D E

Housing Part Number

Spring Part Number

CP-1 Red 450 (204)

1.22 (30.9

7.5 (190.5)

6.0 (152.4)

4.7 (119.4)

2.7 (68.6)

5.5 (139.7) 226102B-00 226115A-00

CP-1 Purple 600 (272)

1.17 (29.7)

7.5 (190.5)

6.0 (152.4)

4.7 (119.4)

2.7 (68.6)

5.5 (139.7) 226102B-00 226116A-00

CP-1 Orange 750 (340)

1.06 (26.9)

7.5 (190.5)

6.0 (152.4)

4.7 (119.4)

2.7 (68.6)

5.5 (139.7) 226102B-00 226117A-00

CP-1 Green 900 (408)

1.02 (25.9)

7.5 (190.5)

6.0 (152.4)

4.7 (119.4)

2.7 (68.6)

5.5 (139.7) 226102B-00 226118A-00

CP-1 Gray 1100 (498)

0.83 (21.0)

7.5 (190.5)

6.0 (152.4)

4.7 (119.4)

2.7 (68.6)

5.5 (139.7) 226102B-00 226119A-00

CP-1 White 1300 (589)

0.74 (18.7)

7.5 (190.5)

6.0 (152.4)

4.7 (119.4)

2.7 (68.6)

5.5 (139.7) 226102B-00 226120A-00

CP-2 Green 1800 (815)

1.02 (25.9)

10.2 (259.1)

9.0 (228.6)

7.7 (195.6)

2.7 (68.6)

5.75 (146.0) 226103B-00 (2) 226118A-00

NOTE: CP-1 housing contains one spring. CP-2 housing contains two identical springs.

Table 4, Neoprene-in-Shear Isolators Dimensions

In. (mm) Type Max. Load

Each Lbs. (kg)

Defl. In. (mm)

A B C D (1) E H L W

McQuay Part Number

RP-3 Green 750 (339)

0.25 (6.4)

2.5 (63.5)

0.5 (12.7)

4.1 (104.1)

0.56 (14.2)

0.25 (6.4)

1.75 (44.4)

5.5 (165)

3.4 (85.7) 216397A-03

RP-3 Gray 1100 (498)

0.25 (6.4)

2.5 (63.5)

0.5 (12.7)

4.1 (104.1)

0.56 (14.2)

0.25 (6.4)

1.75 (44.4)

5.5 (165)

3.4 (85.7) 216397A-05

R-4 Black 1500 (679)

0.25 (6.4)

3.75 (95.3)

0.5 (12.7)

5.0 (127.0)

0.56 (14.2)

0.25 (6.4)

1.6 (41.1)

6.5 (165.1)

4.6 (116.8) 216398A-04

Note (1) "D" is the mounting hole diameter.


Figure 3, Spring Flex Mounting. CP-2

Figure 4, Neoprene-in-Shear Mounting, RP-3

Figure 5, Spring Flex Mounting, CP-1

Figure 6, Neoprene-in-Shear, R4


Water Piping

Vessel Drains at Start-up Condensers are drained of water in the factory and are shipped with condenser drain plugs in the heads removed and stored in a bag in the control panel. Be sure to replace plugs prior to filling the vessel with fluid.

General Due to the variety of piping practices, it is advisable to follow the recommendations of local authorities for code compliance. They can supply the installer with the proper building and safety codes required for a safe and proper installation.

Basically, the piping should be designed with a minimum number of bends and changes in elevation to keep system cost down and performance up. Other piping design considerations include:

1. All piping should be installed and supported to prevent the chiller connections from bearing any strain or weight of the system piping.

2. Vibration eliminators to reduce vibration and noise transmission to the building. 3. Shutoff valves to isolate the unit from the piping system during unit servicing. 4. Manual or automatic air vent valves at the high points of the system. Drains should be

placed at the lowest points in the system. 5. Some means of maintaining adequate system water pressure (e.g., expansion tank or

regulating valve). 6. Temperature and pressure indicators located within 3 feet (0.9 meters) of the inlet and

outlet of the vessels to aid in unit servicing. 7. A strainer or some means of removing foreign matter from the water before it enters the

pump is recommended. It should be placed far enough upstream to prevent cavitation at the pump inlet (consult pump manufacturer for recommendations). The use of a strainer will prolong pump life and thus maintain system performance.

Important Note A cleanable 40-mesh strainer must also be placed in the water line just prior to the inlet of the evaporator. This will aid in preventing foreign material from entering and decreasing the performance of the evaporator.

8. If the unit is used as a replacement chiller on a previously existing piping system, the system should be thoroughly flushed prior to unit installation. Regular water analysis and chemical water treatment on the evaporator and condenser is recommended immediately upon equipment start-up.

9. In the event glycol is added to the water system, as an afterthought for freeze protection, recognize that the refrigerant suction pressure will be lower, cooling performance less, and water side pressure drop will be higher. If the percentage of glycol is large, or if propylene glycol is used instead of ethylene glycol, the added pressure drop and loss of performance could be substantial. Reset the freezestat and low leaving water alarm temperatures. The freezestat is factory set to default at 36°F (2.2°C). Reset the freezestat setting to approximately 4° to 5°F (2.3° to 2.8°C) below the leaving chilled water setpoint temperature. See the section titled “Glycol Solutions” for additional information concerning the use of glycol.

10. A preliminary leak check of the water piping should be made before filling the system.


Note: A water flow switch or pressure differential switch must be mounted in the evaporator outlet water line to signal that there is water flow before the unit will start.

Figure 7, Typical Field Evaporator Water Piping Air

Vent

FlowSwitch

VibrationEliminators

Drain

Outlet

Inlet

PIsolationValves

Strainer

NOTE: Water piping must be supported independently from the unit.

System Water Volume It is important to have adequate water volume in the system to provide an opportunity for the chiller to sense a load change, adjust to the change, and then stabilize. As the expected load change becomes more rapid, a greater water volume is needed. The system water volume is the total amount of water in the evaporator, air handling equipment, and associated piping. If the water volume is too low, operational problems can occur including rapid compressor cycling, rapid loading and unloading of compressors, erratic refrigerant flow in the chiller, improper motor cooling, shortened equipment life and other undesirable occurrences.

For normal comfort cooling applications where the cooling load changes relatively slowly, we recommend a minimum system volume of four minutes times the flow rate (GPM). For example, if the design chiller flow rate is 120 gpm, we recommend a minimum system volume of 480 gallons (120 gpm x 4 minutes).

For process applications where the cooling load can change rapidly, additional system water volume is needed. A process example would be the quenching of hot metal objects. The load would be very stable until the hot metal is dipped into the water tank. Then, the load would increase drastically.

Since there are many other factors that can influence performance, systems can successfully operate below these suggestions. However, as the water volume decreases below these guidelines, the possibility of problems increases.

Variable Chilled Water Flow Reducing chilled water flow in proportion to load can reduce total system power consumption. Certain restrictions apply to the amount and rate of flow change. The rate of flow change should be a maximum of 10 percent of the change, per minute. Do not reduce flow lower than the part load minimum flows listed on page 15.

Chilled Water Piping The system water piping must be flushed thoroughly prior to making connections to the unit evaporator. It is required that a 40-mesh strainer be installed in the return water line before the inlet to the chiller. Lay out the water piping so the chilled water circulating pump discharges into the evaporator inlet.


SuctionCircuit #1SuctionCircuit #2

LiquidCircuit #2LiquidCircuit #1

Leaving ChilledWater Sensor

The return water line must be piped to the evaporator inlet connection and the supply water line must be piped to the evaporator outlet connection. If the evaporator water is piped in the reverse direction, a substantial decrease in capacity and efficiency of the unit will be experienced.

A flow switch must be installed in the horizontal piping of the supply (evaporator outlet) water line to prove water flow before starting the unit.

Drain connections should be provided at all low points in the system to permit complete drainage of the system. Air vents should be located at the high points in the system to purge air out of the system. The evaporators are not equipped with vent or drain connections and provision must be made in the entering and leaving chilled water piping for venting and draining.

Pressure gauges should be installed in the inlet and outlet water lines to the evaporator. Pressure drop through the evaporator should be measured to determine water flow from the flow/pressure drop curves on page 16. Vibration eliminators are recommended in both the supply and return water lines.

Chilled water piping should be insulated to reduce heat loss and prevent condensation. Complete unit and system leak tests should be performed prior to insulating the water piping. Insulation with a vapor barrier would be the recommended type of insulation. If the vessel is insulated, the vent and drain connections must extend beyond the proposed insulation thickness for accessibility.

Chillers not run in the winter should have their water systems thoroughly drained if subject to sub-freezing temperatures. If the chiller operates year-round, or if the system is not drained for the winter, the chilled water piping exposed to sub-freezing ambient temperatures should be protected against freezing by wrapping the lines with a heater cable. In addition, an adequate percentage of glycol should be added to the system to further protect the system during low ambient temperature periods. It should be noted that water piping that has been left drained is subject to more corrosion than if filled with water. Use of a Vapor Corrosion Inhibitor (VCI) or some other protection should be considered.

Chilled Water Sensor Figure 8, Thermostat Well Location

The chilled water sensor is factory installed in the leaving water connection on the evaporator. Care should be taken not to damage the sensor cable or lead wires when working around the unit. It is also advisable to check the lead wire before running the unit to be sure that it is firmly anchored and not rubbing on the frame or any other component. If the sensor is ever removed from the well for servicing, care must be taken to not wipe off the heat-conducting compound supplied in the well.

CAUTION The thermostat bulb should not be exposed to water temperatures above 125°F

(51.7°C) since this will damage it.


Flow Switch A water flow switch must be mounted in the leaving evaporator and condenser water line to prove adequate water flow before the unit can start. This will safeguard against slugging the compressors on start-up. It also serves to shut down the unit in the event that water flow is interrupted to guard against evaporator freeze-up. A flow switch is available from McQuay under part number 01750330. It is a “paddle” type switch and adaptable to any pipe size from 1 in. (25 mm) to 6 in. (152 mm) nominal. Certain minimum flow rates are required to close the switch and are listed in Table 5. Electrical connections in the unit control center should be made at terminals 33 and 43 (chilled water) and 41 and 53 (condenser water). The normally open contacts of the flow switch should be wired between these two terminals. There is also a set of normally closed contacts on the switch that could be used for an indicator light or an alarm to indicate when a “no flow” condition exists. 1. Apply pipe sealing compound to only the threads of the switch and screw unit into 1 in.

(25 mm) reducing tee. The flow arrow must be pointed in the correct direction. 2. Piping should provide a straight length before and after the flow switch of at least five

times the pipe diameter without any valves, elbows, or other flow restricting elements. 3. Trim flow switch paddle if needed to fit the pipe diameter. Make sure paddle does not

hang up in pipe.

CAUTION Make sure the arrow on the side of the switch is pointed in the direction of flow.

The flow switch is designed to handle the control voltage and should be connected according to the wiring diagram (see wiring diagram inside control box door). Incorrect installation will cause improper operation and possible

evaporator damage.

Table 5, Flow Switch Flow Rates inch 2 2 1/2 3 4 5 6 Pipe Size mm 51 63 76 102 (125) (150) gpm 13.7 17.9 24.2 35.3 48.6 60.3 Flow Lpm 51.8 67.8 91.6 134.0 184.0 228.0 gpm 9.4 12.1 16.4 27.0 37.4 46.8

Minimum Adjustment No

Flow Lpm 35.6 45.8 62.1 102.0 142.0 177.0 gpm 56.4 71.3 89.0 118.0 178.0 245.0 Flow Lpm 214.0 270.0 337.0 446.0 674.0 927.0 gpm 47.4 59.2 72.5 105.0 160.0 225.0

Maximum Adjustment No

Flow Lpm 179.0 224.0 274.0 397.0 606.0 852.0

Glycol Solutions When using a glycol solution, the chiller capacity, flow rate, evaporator pressure drop, and chiller power input can be calculated using the following formulas and reference to Table 6 for ethylene glycol and Table 7 for propylene glycol.

1. Capacity, Capacity is reduced compared to that with plain water. To find the reduced value, multiply the chiller’s capacity when using water by the capacity correction factor C to find the chiller’s capacity when using glycol.

2. Flow, To determine evaporator gpm (or ΔT) knowing ΔT (or gpm) and capacity:

TablesFromGCorrectionFlowxT

CapacityGlycolxGPMGlycol

Δ=

24


For Metric Applications -- Determine evaporator lps (or ΔT) knowing ΔT (or lps) and kW:

TablesfromGCorrectionFlowxTx

kWLpsGlycolΔ

=18.4

3. Pressure Drop, To determine glycol pressure drop through the cooler, enter the water pressure drop graph on page 15 at the actual glycol flow. Multiply the water pressure drop found there by P to obtain corrected glycol pressure drop.

4. Power, To determine glycol system kW, multiply the water system kW by factor K.

Test coolant with a clean, accurate, glycol solution hydrometer (similar to that found in service stations) to determine the freezing point. Obtain percent glycol from the freezing point found in Table 6 or Table 7. On glycol applications the supplier normally recommends that a minimum of 25% solution by weight be used for protection against corrosion or the use of additional inhibitors.

Note: The effect of glycol in the condenser is negligible. As glycol increases in temperature, its characteristics have a tendency to mirror those of water. Therefore, for selection purposes, there is no derate in capacity for glycol in the condenser.

Table 6, Ethylene Glycol Freezing Point Percent

Glycol °F °C C (Capacity) K (Power) G (Flow) P (Pressure

Drop) 10 26 -3 0.991 0.996 1.013 1.070 20 18 -8 0.982 0.992 1.040 1.129 30 7 -14 0.972 0.986 1.074 1.181 40 -7 -22 0.961 0.976 1.121 1.263 50 -28 -33 0.946 0.966 1.178 1.308

Table 7, Propylene Glycol Freezing Point Percent

Glycol °F °C C (Capacity) K (Power) G (Flow) P (Pressure

Drop) 10 26 -3 0.987 0.992 1.010 1.068 20 19 -7 0.975 0.985 1.028 1.147 30 9 -13 0.962 0.978 1.050 1.248 40 -5 -21 0.946 0.971 1.078 1.366 50 -27 -33 0.929 0.965 1.116 1.481

CAUTION Do not use automotive antifreeze. Industrial glycols must be used. Automotive antifreeze contains inhibitors that causes plating on copper tubes. The type and

handling of glycol used must be consistent with local codes.

Condenser Water Piping Arrange the condenser water so the water enters the bottom connection of the condenser. The condenser water will discharge from the top connection. Failing to arrange the condenser water as stated above will negatively affect the capacity and efficiency. Install pressure gauges in the inlet and outlet water lines to the condenser. Pressure drop through the condenser should be measured to determine flow on the pressure drop/flow curves on page 17. Vibration eliminators are recommended in both the supply and return water lines. Install a 20-mesh strainer in the inlet piping to the condenser.


Circuit #1 Outlet

Condenser

TemperatureControlValve

CondenserWater

Circuit #2 Outlet

Circuit #1 Inlet

Circuit #2 Inlet

Water-cooled condensers can be piped for use with cooling towers, well water, or heat recovery applications. Cooling tower applications should be made with consideration of freeze protection and scaling problems. Contact the cooling tower manufacturer for equipment characteristics and limitations for the specific application. Head pressure control must be provided if the entering condenser water can fall below 60°F. The WGZ condenser has two refrigerant circuits with a common condenser water circuit. This arrangement makes head pressure control with discharge pressure actuated control valves difficult. If for some reason the tower water temperature cannot be maintained at a 60°F minimum, or when pond, lake, or well water that can fall below 60°F (15°C) is used as the condensing medium, special discharge pressure control must be used. A water recirculating system with recirculating pump as shown in Figure 9 is recommended. This system also has the advantage of maintaining tube velocity to help prevent tube fouling. The pump should cycle with the chiller. Figure 9, Recirculating Discharge Pressure Control System

Minimum Flow Rates Design Full Load Chilled Water Flows The evaporator flow rates and pressure drops shown on the following page are for full load design purposes. The maximum flow rate and pressure drop are based on a 6-degree temperature drop. Avoid higher flow rates with resulting lower temperature drops to prevent potential control problems resulting from very small control bands and limited start up/shut off temperature changes.

The minimum flow and pressure drop is based on a full load evaporator temperature drop of 16-degrees.

Minimum Flows for Variable Flow Pumping Systems This design full load minimum flow is not to be confused with the part load minimum flow rate that must be maintained for chillers operating in primary variable flow pumping systems. As chiller load drops, the flow rate for this pumping system also reduces. See the following table for the minimum part load flow rates. Other design practices for variable flow systems requiring a range of evaporator flow rates can be found on page 11.

These minimum flow rates assume that flow will be reduced proportionally to the cooling load.

Table 8, Minimum Part Load Flow Rates WGZ Model 030 035 040 045 050 055 060 070 080 090 100 110 120

Minimum Part Load Flow 30 34 38 43 47 53 58 67 74 83 91 102 113


Water Pressure Drop Figure 10, Evaporator Water Pressure Drop, WGZ 030A through 120A

30 40 50 60 70 80 90 100 200 300 400 500 600

2

3

4

5

6

7

8

910

20

30

40

Flow Rate (GPM)

Pres

sure

Dro

p (ft

of w

ater

)Flow Rate (L/s)

1.9 2.5 3.2 3.8 4.4 5.0 5.7 6.3 12.6 18.9 25.2 31.5 37.9

6

12

18

24

2730

9

21

15

60

90

120Pressure D

rop (kPa)44.2

700

WGZ 030

1 3

WGZ 080

WGZ 040

WGZ 050

WGZ 035

WGZ 045

WGZ 055WGZ 070

WGZ 090

WGZ 060

WGZ 100 - 120

Minimum Flow Nominal Flow Maximum Flow Inch-Pound S.I. Inch-Pound S.I. Inch-Pound S.I.

WGZ Model

GPM Ft. L/S kPa GPM Ft. L/S kPa GPM Ft. L/S kPa 030 56.9 2.66 3.59 7.96 94.8 7.40 5.98 22.11 158.0 20.55 9.97 61.43 035 62.8 3.25 3.96 9.71 104.7 9.02 6.61 26.97 174.5 25.07 11.01 74.93 040 72.2 2.83 4.55 8.45 120.3 7.85 7.59 23.46 200.5 21.80 12.65 65.17 045 79.6 3.43 5.02 10.26 132.6 9.54 8.37 28.51 221.0 26.49 13.94 79.18 050 87.5 3.02 5.52 9.02 145.8 8.38 9.20 25.05 243.0 23.28 15.33 69.58 055 97.7 3.77 6.17 11.26 162.9 10.46 10.28 31.27 271.5 29.06 17.13 86.85 060 107.3 3.38 6.77 10.11 178.8 9.39 11.28 28.07 298.0 26.09 18.80 77.97 070 122.4 3.45 7.72 10.31 204.0 9.58 12.87 28.64 340.0 26.62 21.45 79.56 080 140.4 3.92 8.86 11.72 234.0 10.89 14.76 32.56 390.0 30.26 24.61 90.45 090 154.4 3.95 9.74 11.81 257.4 10.97 16.24 32.80 429.0 30.48 27.07 91.11 100 168.7 3.55 10.64 10.62 281.1 9.87 17.73 29.50 468.5 27.41 29.56 81.94 110 191.2 4.56 12.06 13.64 318.6 12.68 20.10 37.89 531.0 35.21 33.50 105.26 120 211.0 5.56 13.31 16.61 351.6 15.44 22.18 46.15 586.0 42.89 36.97 128.19

Note: Minimum, nominal, and maximum flows are at a 16°F, 10°F, and 6°F chilled water temperature range respectively and at ARI tons. See previous page.


Figure 11, Condenser Water Pressure Drop, WGZ 030AW through 120AW

30 40 50 60 70 80 90 100 200 300 400 500 600

2

3

4

5

6

7

8

910

20

30

40

50

60

70

Flow Rate (GPM)

Pres

sure

Dro

p (ft

of w

ater

)

Flow Rate (L/s)

1.9 2.5 3.2 3.8 4.4 5.0 5.7 6.3 12.6 18.9 25.2 31.5 37.9

6

12

18

24

2730

9

21

15

60

90

120

150

180

210Pressure D

rop (kPa)44.2

700

WGZ 030, 035

WGZ 040, 045

WGZ 050, 055 WGZ 090

WGZ 080

WGZ 070

WGZ 060

WGZ 100 - 120

Minimum Flow Nominal Flow Maximum Flow

Flow Rate Pressure Drop Flow Rate Pressure Drop Flow Rate Pressure Drop WGZ Model

gpm L/s ft. kPa gpm L/s ft. kPa gpm L/s ft. kPa

030 56.9 3.59 2.66 7.96 94.8 5.98 7.40 22.11 158.0 9.97 20.55 61.43 035 62.8 3.96 3.25 9.71 104.7 6.61 9.02 26.97 174.5 11.01 25.07 74.93 040 72.2 4.55 2.83 8.45 120.3 7.59 7.85 23.46 200.5 12.65 21.80 65.17 045 79.6 5.02 3.43 10.26 132.6 8.37 9.54 28.51 221.0 13.94 26.49 79.18 050 87.5 5.52 3.02 9.02 145.8 9.20 8.38 25.05 243.0 15.33 23.28 69.58 055 97.7 6.17 3.77 11.26 162.9 10.28 10.46 31.27 271.5 17.13 29.06 86.85 060 107.3 6.77 3.38 10.11 178.8 11.28 9.39 28.07 298.0 18.80 26.09 77.97 070 122.4 7.72 3.45 10.31 204.0 12.87 9.58 28.64 340.0 21.45 26.62 79.56 080 140.4 8.86 3.92 11.72 234.0 14.76 10.89 32.56 390.0 24.61 30.26 90.45 090 154.4 9.74 3.95 11.81 257.4 16.24 10.97 32.80 429.0 27.07 30.48 91.11 100 168.7 10.64 3.55 10.62 281.1 17.73 9.87 29.50 468.5 29.56 27.41 81.94 110 191.2 12.06 4.56 13.64 318.6 20.10 12.68 37.89 531.0 33.50 35.21 105.26 120 211.0 13.31 5.56 16.61 351.6 22.18 15.44 46.15 586.0 36.97 42.89 128.19


Refrigerant Piping

Unit with Remote Condenser General Refrigerant piping, to and from the unit, should be sized and installed according to the latest ASHRAE Handbook. It is important that the unit piping be properly supported with sound and vibration isolation between tubing and hanger, and that the discharge lines be looped at the condenser and trapped at the compressor to prevent refrigerant and oil from draining into the compressors. Looping the discharge line also provides greater line flexibility.

The discharge gas valves, liquid line solenoids, filter-driers, moisture indicators, and thermostatic expansion valves are all factory mounted as standard equipment with the water chiller.

For remote condenser application (WGZ-AA) such as air-cooled or evaporative condenser, the chillers are shipped with an R-22 holding charge. Some special order units may have R-407c refrigerant. The unit is evacuated in the factory to 500 microns before charging with a holding charge of R-22 (407c) refrigerant. The unit is leak tested after charging and before shipment.

The liquid line has a shutoff valve upstream from the liquid line solenoid valve and a copper tube cap to be brazed on this line after test to seal this line for shipment.

The discharge line has a ball valve installed between the compressor and the discharge stub tube with a copper tube cap brazed on the line after test to seal it for shipment.

The discharge gas valves, liquid line solenoids, filter-driers, moisture indicators, and thermostatic expansion valves are all factory-mounted as standard equipment with the water chiller.

DANGER Do not apply heat, such as a brazing torch, to a sealed unit, vessel, or component. Internal gases can increase the internal pressure and cause a life-threatening explosion. Open the system when heating. The short line between a valve and brazed end cap can be drilled to

vent it. Note that the valve may leak and the entire unit charge may be open to the cap.

It is important that the unit be kept tightly closed until the remote condenser is installed, piped to the unit and the high side evacuated. NOTE: it is possible to maintain a positive refrigerant pressure in the unit when a small leak is present. Therefore, add refrigerant to the unit to achieve sufficient pressure to allow a good leak test and carefully leak test the unit. Correct any leaks found.

When the field piping has been leak tested, evacuated, and is ready to charge, the unit valves can be opened and the system charged.

Alternate method: an alternate method is to open up the unit to the field piping and to pressure test, evacuate and charge the entire system together at one time. Many people feel that this is a more straight-forward approach.

Refrigerant piping, to and from the unit, should be sized and installed according to the latest ASHRAE Handbook. It is important that the unit piping be properly supported with sound and vibration isolation between tubing and hanger, and that the discharge lines be looped at


the condenser and trapped at the compressor to prevent refrigerant and oil from draining into the compressors. Looping the discharge line also provides greater line flexibility.

NOTE: Do not run refrigerant piping underground.

After the equipment is properly installed, leak tested, and evacuated, it can be charged with R-22, and run at design load conditions. Add charge until the liquid line sight glass is clear, with no bubbles flowing to the expansion valve. Total operating charge will depend on the air-cooled condenser used and volume of the refrigerant piping.

NOTE: On WGZ-AA units (units with remote condensers), the installer is required to record the refrigerant charge by stamping the total charge and the charge per circuit on the serial plate in the appropriate blocks provided for this purpose.

The following discussion is intended for use as a general guide to the piping of air-cooled condensers.

Discharge lines must be designed to handle oil properly and to protect the compressor from damage that can result from condensing liquid refrigerant in the line during shutdown. Total friction loss for discharge lines of 3 to 6 psi (20.7 to 41.4 kPa) is considered good design. Careful consideration must be given for sizing each section of piping to insure that gas velocities are sufficient at all operating conditions to carry oil. If the velocity in a vertical discharge riser is too low, considerable oil can collect in the riser and the horizontal header, causing the compressor to lose its oil and result in damage due to lack of lubrication. When the compressor load is increased, the oil that had collected during reduced loads can be carried as a slug through the system and back to the compressor, where a sudden increase of oil concentration can cause liquid slugging and damage to the compressor.

Any horizontal run of discharge piping should be pitched away from the compressor approximately 1/8 inch (6.4 mm) per foot (meter) or more. This is necessary to move, by gravity, any oil lying in the header. Oil pockets must be avoided because oil needed in the compressor would collect at such points and the compressor crankcase can become starved.

It is recommended that any discharge lines coming into a horizontal discharge header rise above the centerline of the discharge header. This is necessary to prevent any oil or condensed liquid from draining to the compressor heads when the compressor is not running.

In designing liquid lines, it is important that the liquid reach the expansion valve without flash gas since this gas will reduce the capacity of the valve. Because “flashing” can be caused by a pressure drop in the liquid line, the pressure losses due to friction and changes in static head should be kept to a minimum.

A check valve must be installed in the liquid line in all applications where the ambient temperature can drop below the equipment room temperature. This prevents liquid migration to the condenser, helps maintain a supply of refrigerant in the liquid line for initial start-up, and keeps liquid line pressure high enough on “off” cycle to keep the expansion valve closed.

On systems as described above, a relief valve or relief-type check valve, must be used in the liquid line as shown in piping systems (shown in Figure 12 and Figure 13). Its purpose is to relieve dangerous hydraulic pressures that could be created as cool liquid refrigerant trapped in the line between the check valve and the expansion or shutoff valve warms up. A relief device is also recommended in the hot gas piping at the condenser coil as shown in Figure 12 and Figure 13.

Install a discharge check valve in the discharge line, in a horizontal run, close to the condenser.


Typical Arrangements Figure 12 illustrates a typical piping arrangement involving a remote air-cooled condenser located at a higher elevation than the compressor and receiver. This arrangement is commonly encountered when the air-cooled condenser is on a roof and the compressor and receiver are on grade level or in a basement equipment room.

Notice, in both illustrations, that the hot gas line is looped at the bottom and top of the vertical run. This is done to prevent oil and condensed refrigerant from flowing back into the compressor and causing damage. The highest point in the discharge line should always be above the highest point in the condenser coil. It is advisable to include a purging vent at this point to extract non-condensables from the system.

Figure 13 illustrates another very common application where the air-cooled condenser is located on essentially the same level as the compressor and receiver. The discharge line piping in this case is not too critical. The principal problem encountered with this arrangement is that there is frequently insufficient vertical distance to allow free drainage of liquid refrigerant from the condenser coil to the receiver.

The receiver is used when it is desired to have refrigerant storage capacity, in addition to the pumpdown capability of the condenser.


Condenser

Relief Valve

Check Valve

Purge Valve

Discharge Line

Loop

Receiver

ReceiverBypass

ToEvap.

PreferredSubcoolerHook-up

Relief Valve(Vent to Outdoorsor to Condenser Sideof Liquid LineCheck Valve)

Pitch

CheckValve

Subcooler

Condenser

Relief Valve

Check Valve

Purge Valve

Relief Valve(Vent to Outdoorsor to Condenser Sideof Liquid LineCheck Valve)

Pitch

CheckValve

Discharge Line

Receiver

ReceiverBypass

ToEvap.

PreferredSubcoolerHook-up

CheckValve

Subcooler

Figure 12, Condenser Above Compressor and Optional Receiver Installation

Figure 13, Condenser and Compressor on Same Level, Optional Receiver Installation

The receiver shown is optional and not used on many installations. It is bypassed during normal operation.


Factory-Mounted Condenser Units with the standard water-cooled, factory-mounted condenser are provided with complete refrigerant piping and full operating refrigerant charge at the factory.

There is a remote possibility on water-cooled units utilizing low temperature pond or river water as a condensing medium, and if the water valves leak, that the condenser and liquid line refrigerant temperature could drop below the equipment room temperature on the “off” cycle. This problem only arises during periods when cold water continues to circulate through the condenser and the unit remains off due to satisfied cooling load.

If this condition occurs:

1. Cycle the condenser pump off with the unit. 2. Check the liquid line solenoid valve for proper operation.

Relief Valve Piping The ANSI/ASHRAE Standard 15, Safety Standard for Refrigeration Systems, specifies that pressure relief valves on vessels containing Group 1 refrigerant (R-22) “shall discharge to the atmosphere at a location not less than 15 feet (4.6 meters) above the adjoining ground level and not less than 20 feet (6.1 meters) from any window, ventilation opening or exit in any building.” The piping must be provided with a rain cap at the outside terminating point and with a drain at the low point on the vent piping to prevent water buildup on the atmospheric side of the relief valve. In addition, a flexible pipe section should be installed in the line to eliminate any piping stress on the relief valve(s).

The size of the discharge pipe from the pressure relief valve should not be less than the size of the pressure relief outlet. When two or more vessels are piped together, the common header and piping to the atmosphere should not be less than the sum of the area of each of the lines connected to the header.

NOTE: Fittings should be provided to permit vent piping to be easily disconnected for inspection or replacement of the relief valve.

Figure 14, Relief Valve Piping


Dimensional Data WGZ-AW Water-Cooled Figure 15, WGZ 030AW through WGZ 055AW

L

A

121.43085

(4) .875" (22 mm)

Inlet

Outlet

OutletInlet

H

W

Y

1.538

29711

1.538

13.25337

8204

14354

27.8707

52.41331

Z

X

Condenser

Evaporator

12.3311

20508

Control Connection

Evaporator

Power Connections(2) .875" (22 mm)

Mounting Holes

Door Swing Recommendedfor Servicing

38965

36915

4.5114

MicroTech II User Interface

Relief Valves(1) Each End

T

Maximum Overall Dimensions

in (mm)

Chilled Water Connection

in. (mm) Victaulic

Condenser Water

Connections in. (mm) Victaulic

Center of Gravity WGZ Model

Number

L W H Size A Size T X Y Z

030 134.1 (3406)

32 (813)

63.5 (1613)

3” (76)

114.3 (2903)

4 (102)

3.0 (76.2)

62.9 (1596)

26.8 (680)

13.4 (340)

035 134.1 (3406)

32 (813)

63.5 (1613)

3” (76)

115.2 (2926)

4 (102)

3.0 (76.2)

63.3 (1607)

26.9 (682)

13.4 (340)

040 134.1 (3406)

32 (813)

63.5 (1613)

3” (76)

116.5 (2959)

4 (102)

3.0 (76.2)

63.7 (1618)

26.9 (682)

13.4 (340)

045 134.1 (3406)

32 (813)

63.5 (1613)

3” (76)

117.8 (2992)

4 (102)

3.0 (76.2)

64.1 (1627)

27.1 (688)

13.4 (340)

050 134.1 (3406)

32 (813)

63.5 (1613)

3” (76)

119.1 (3025)

4 (102)

3.0 (76.2)

64.6 (1640)

27.1 (688)

13.4 (340)

055 134.1 (3406)

32 (813)

63.5 (1613)

3” (76)

121.0 (3073)

4 (102)

3.0 (76.2)

63.6 (1614)

27.3 (693)

13.3 (338)

See NOTES on the bottom of page 24.


Figure 16, WGZ-060AW through WGZ-120AW

H

W

9.8248

18458

33.5852

58.11476

121.13075

13.25337

1.538 737

1.538

A

X

Y

Z

(4) .875" (22 mm)

Inlet

Outlet

Outlet

InletCondenser

Diameter Mounting Holes

Evaporator

T

Evaporator

7.7196

L

Control Connection

Power Connections

15382

20508

(2) .875" (22 mm)

Door SwingClearance Recommended

for Servicing

38965

36915

4.5114




in (mm)

Chiller Water Connection

in. (mm) Victaulic

Condenser Water Connections

in. (mm) Victaulic

Center of Gravity WGZ Model

Number L W H Size A Size T X Y Z

060 144.2 (3663)

32 (813)

66 (1676)

3 (76)

117.3 (2980)

5 (127)

10.3 (263)

61.0 (1549)

30.5 (775)

13.4 (340)

070 148.2 (3764)

32 (813)

66 (1676)

3 (76)

119.5 (3036)

5 (127)

14.4 (367)

60 (1525)

31.6 (804)

13.4 (340)

080 148.2 (3764)

32 (813)

66 (1676)

3 (76)

122.6 (3114)

5 (127)

14.4 (367)

61.1 (1553)

32.8 (834)

13.4 (340)

090 149 (3785)

32 (813)

66 (1676)

3 (76)

126.6 (3216)

5 (127)

15.3 (388)

62.7 (1591)

33.2 (843)

13.4 (340)

100 149 (3785)

32 (813)

66 (1676)

3 (76)

128.9 (3274)

5 (127)

15.3 (388)

63.6 (1614)

33.0 (839)

13.4 (340)

110 149 (3785)

32 (813)

66 (1676)

3 (76)

128.9 (3274)

5 (127)

15.4 (390)

63.3 (1608)

33.6 (854)

13.4 (340)

120 149 (3785)

32 (813)

66 (1676)

3 (76)

128.9 (3274)

5 (127)

15.4 (390)

61.2 (1555)

34.2 (870)

13.4 (340)

NOTES 1. Allow a minimum of three feet (one meter) service clearance on all four sides of the unit. Allow sufficient space at one end for

tube cleaning or replacement.


2. Allow two additional inches in width for the optional disconnect switch handle. WGZ-AA Remote Condenser Figure 17, Dimensions, WGZ 030AA – WGZ 055AA

121.43085

L A

X

B C D F

"G" Disch. System #2 "G" Disch. System #1

"E" Liquid System #2 "E" Liquid System #1

Inlet

Outlet

Power Connections(2) - .875 (22 mm)

Evaporator

Control Connection

(4) - .875 (22 mm)

13.8350

27.8707

52.41331

24.1613

"G" Disch Conn

12.5318

20508

4.5114

H

Y

"E" Liquid Conn

W

1.538

29737

1.538

Z

Mounting Holes

Door SwingClearance

Recommendedfor Servicing

38965

36915


T

Refrigerant Piping Connections Maximum Overall Dimensions

In. (mm)

Evaporator Connection

In. (mm) Victaulic

System #1 System #2 Connection Size Center of Gravity WGZ

Model

L W H Size A Liquid

F Discharge

C Liquid

D Discharge

B Liquid

E Discharge

G T X Y Z

030 125.4 (3186)

32 (813)

63.5 (1613)

3 (76)

114.3 (2903)

54.6 (1386)

39.2 (996)

53.7 (1363)

43.3 (1101)

.875 (22)

1.125 (29)

2.0 (51)

66.0 (1677)

31.0 (788)

14.0 (356)

035 125.4 (3186)

32 (813)

63.5 (1613)

3 (76)

115.2 (2926)

54.6 (1386))

39.2 (996)

53.7 (1363)

43.3 (1101)

.875 (22)

1.125 (29)

2.0 (51))

66.5 (1689)

31.2 (792)

14.0 (356)

040 125.4 (3186)

32 (813)

63.5 (1613)

3 (76)

116.5 (2959)

54.6 (1386)

39.2 (996)

53.7 (1363)

43.3 (1101)

.875 (22)

1.125 (29)

2.0 (51)

67.0 (1702)

31.3 (796)

14.0 (356)

045 125.4 (3186)

32 (813)

63.5 (1613)

3 (76)

117.8 (2992)

54.6 (1386)

39.2 (996)

53.7 (1363))

43.3 (1101)

.875 (22)

1.125 (29)

2.0 (51))

67.4 (1712)

31.5 (801

13.9 (354)

050 125.4 (3186)

32 (813)

63.5 (1613)

3 (76)

119.1 (3025)

54.6 (1386)

39.2 (996)

53.7 (1363)

43.3 (1101)

.875 (22)

1.125 (29)

2.0 (51)

68.0 (1728)

31.7 (804)

13.9 (354

055 125.4 (3186)

32 (813)

63.5 (1613)

3 (76)

121.0 (3073

60.9 (1546)

44.6 (1132)

47.4 (1203)

38.0 (964)

.875 (22)1.125 (29)

1.125 (29) 1.375 (35)

2.0 (51))

66.6 (1692)

31.8 (809)

13.8 (351)

See NOTES on the bottom of page 24.


Figure 18, Dimensions WGZ 060AA – 120AA

H

W

9.8248

18458

33.5852

58.11476

121.13075

13.25337

1.538 737

1.538

A

X

Y

Z

(4) .875" (22 mm)

Inlet

Outlet

Outlet

InletCondenser

Diameter Mounting Holes

Evaporator

T

Evaporator

7.7196

L

Control Connection

Power Connections

15382

20508

(2) .875" (22 mm)

Door SwingClearance Recommended

for Servicing

38965

36915

4.5114




in (mm)

Chiller Water Connection

in. (mm) Victaulic

Condenser Water Connections

in. (mm) Victaulic Center of Gravity WGZ

Model Number

L W H Size A Size T X Y Z

060 144.2 (3663)

32 (813)

66 (1676)

3 (76)

117.3 (2980)

5 (127)

10.3 (263)

61.0 (1549)

30.5 (775)

13.4 (340)

070 148.2 (3764)

32 (813)

66 (1676)

3 (76)

119.5 (3036)

5 (127)

14.4 (367)

60 (1525)

31.6 (804)

13.4 (340)

080 148.2 (3764)

32 (813)

66 (1676)

3 (76)

122.6 (3114)

5 (127)

14.4 (367)

61.1 (1553)

32.8 (834)

13.4 (340)

090 149 (3785)

32 (813)

66 (1676)

3 (76)

126.6 (3216)

5 (127)

15.3 (388)

62.7 (1591)

33.2 (843)

13.4 (340)

100 149 (3785)

32 (813)

66 (1676)

3 (76)

128.9 (3274)

5 (127)

15.3 (388)

63.6 (1614)

33.0 (839)

13.4 (340)

110 149 (3785)

32 (813)

66 (1676)

3 (76)

128.9 (3274)

5 (127)

15.4 (390)

63.3 (1608)

33.6 (854)

13.4 (340)

120 149 (3785)

32 (813)

66 (1676)

3 (76)

128.9 (3274)

5 (127)

15.4 (390)

61.2 (1555)

34.2 (870)

13.4 (340)

Notes: 1. Allow a minimum of 3 ft (1 meter) service clearance on all 4 sides of the unit. Allow sufficient space on one end for condenser tube

cleaning and replacement. Allow 4 ft clearance in front of the control panel. 2. Allow two additional inches in width for optional disconnect switch.


Physical Data

AW Water-Cooled Table 9, WGZ 030AW – WGZ 055AW

WGZ UNIT SIZE 030 035 040 045 050 055 Unit capacity @ ARI conditions tons, (kW) (1) 31.6 (111.1) 34.9 (122.7) 40.1 (141) 44.2 (155) 48.6 (171) 54.3 (191)

No. Circuits 2 2 2 2 2 2 COMPRESSORS (2) Nominal Tons 7.5 9 9 9 10 10 13 10 13 13 13 15 Number 2 2 2 2 2 2 2 2 2 2 2 2 Unloading Steps, % 27 / 50 / 77 25 / 50 / 75 25 / 50 / 75 28 / 50 / 78 25 / 50 / 75 27 / 50 / 77 Oil Charge per Compressor oz., (l) 140 (4.1) 140 (4.1) 140 (4.1) 140 (4.1) 140 (4.1) 140 (4.1) CONDENSER Number 1 1 1 1 1 1 No. Refrigerant Circuits 2 2 2 2 2 2 Diameter, in., (mm) 10 (254) 10 (254) 10 (254) 10 (254) 10 (254) 10 (254) Tube Length, in., (mm) 120 (3048) 120 (3048) 120 (3048) 120 (3048) 120 (3048) 120 (3048) Design W.P.PSIG, (kPa): Refrigerant Side 450 (3102) 450 (3102) 450 (3102) 450 (3102) 450 (3102) 450 (3102) Water Side 232 (1599) 232 (1599) 232 (1599) 232 (1599) 232 (1599) 232 (1599) No. of Passes 2 2 2 2 2 2 Pump-Out Capacity, lb., (kg) (3) 279 (126.6) 273 (123.8) 260 (117.9) 253 (114.8) 240 (108.9) 234 (106.1) Connections: Water In & Out, in, (mm) Victaulic 4 (102) 4 (102) 4 (102) 4 (102) 4 (102) 4 (102) Relief Valve, Flare In., (mm) ½ (12.7) ½ (12.7) ½ (12.7) ½ (12.7) ½ (12.7) ½ (12.7) Purge Valve, Flare In., (mm) ½ (12.7) ½ (12.7) ½ (12.7) ½ (12.7) ½ (12.7) ½ (12.7) Vent & Drain, in. (mm) FPT ½ (12.7) ½ (12.7) ½ (12.7) ½ (12.7) ½ (12.7) ½ (12.7) Liquid Subcooling Integral Integral Integral Integral Integral Integral EVAPORATOR Number 1 1 1 1 1 1 No. Refrigerant Circuits 2 2 2 2 2 2 Water Volume, gallons, (l) 3.9 (14.7) 4.3 (16.4) 5 (18.9) 5.7 (21.4) 6.3 (23.9) 7.2 (27.3) Refrig. Side D.W.P. Psig, (kPa) 450 (3102) 450 (3102) 450 (3102) 450 (3102) 450 (3102) 450 (3102) Water Side D.W.P,. psig, (kPa) 363 (2503) 363 (2503) 363 (2503) 363 (2503) 363 (2503) 363 (2503) Water Connections: Inlet & Outlet, in., (mm) Victaulic 3 (76) 3 (76) 3 (76) 3 (76) 3 (76) 3 (76) Drain & Vent (NPT INT.) Field Field Field Field Field Field UNIT DIMENSIONS Length In., (mm) 134.1 (3406) 134.1 (3406) 134.1 (3406) 134.1 (3406) 134.1 (3406) 134.1 (3406)Width In., (mm) 32 (813) 32 (813) 32 (813) 32 (813) 32 (813) 32 (813) Height In., (mm) 63.5 (1613) 63.5 (1613) 63.5 (1613) 63.5 (1613) 63.5 (1613) 63.5 (1613) UNIT WEIGHTS Operating Weight, lb., (kg) 2691 (1223) 2760 (1252) 2864 (1299) 2966 (1345) 3058 (1387) 3213 (1457)Shipping Weight, lb., (kg) 2641 (1198) 2696 (1223) 2772 (1257) 2853 (1294) 2918 (1324) 3063 (1389)Cir # 1,Opn. Charge, lb., (kg) R-22 50 (599) 50 (22.5) 47 (21.3) 46 (20.8) 44 (20.0) 45 (20.2) Cir # 2,Opn. Charge, lb., (kg) R-22 50 (599) 50 (22.5) 47 (21.3) 46 (20.8) 44 (20.0) 45 (20.2)

Notes: 1. Certified in accordance with ARI Standard 550/590-98. 2. All units have two parallel compressors per circuit. 3. 80% Full R-22 at 90°F (32°C) per unit.


Table 10, WGZ-060AW - WGZ-100AW WGZ UNIT SIZE 060 070 080 090 100 Unit capacity @ ARI conditions tons, (kW) (1) 59.6 (209) 68.0 (239) 78.0 (274) 84.4 (297) 93.7 (330)

No. Circuits 2 2 2 2 2 COMPRESSORS (2) Nominal Tons 15 15 15 20 20 20 20 25 25 25 Number (2) 2 2 2 2 2 2 2 2 2 2 Unloading Steps, % 25 / 50 / 75 28 / 50 / 78 25 / 50 / 75 27 / 50 / 77 25 / 50 / 75 Oil Charge, per compressor oz. (l) 140 (4.1) 140 (4.1) 148 (4.3) 148 (4.3) 200 (5.9) 200 (5.9 200 (5.9CONDENSER Number 1 1 1 1 1 No. Refrigerant Circuits 2 2 2 2 2 Diameter, in. (mm) 14 (356) 14 (356) 14 (356) 14 (356) 14 (356) Tube Length, in. (mm) 120 (3048) 120 (3048) 120 (3048) 120 (3048) 120 (3048) Design W.P., psig (kPa): Refrigerant Side 450 (3102) 450 (3102) 450 (3102) 450 (3102) 450 (3102) Water Side 232 (1599) 232 (1599) 232 (1599) 232 (1599) 232 (1599) No. of Passes 2 2 2 2 2 Pump-Out Capacity lb., (kg) (3) 481 (218.2) 462 (209.6) 449 (203.7) 429 (194.6) 409 (185.5)

Water Connections, Victaulic: Water In & Out, in., (mm) (4) 5 (127) 5 (127) 5 (127) 5 (127) 5 (127) Relief Valve, Flare in., (mm) ½ (12.7) ½ (12.7) ½ (12.7) ½ (12.7) ½ (12.7) Purge Valve, Flare in. (mm) ½ (12.7) ½ (12.7) ½ (12.7) ½ (12.7) ½ (12.7) Vent & Drain, in. (mm) FPT ½ (12.7) ½ (12.7) ½ (12.7) ½ (12.7) ½ (12.7) Liquid Subcooling Integral Integral Integral Integral Integral EVAPORATOR Number 1 1 1 1 1 No. Refrigerant Circuits 2 2 2 2 2 Water Volume, gallons (l) 8.1 (30.7) 9.2 (34.9) 10.8 (40.7) 12.8 (48.3) 13.9 (52.5) Refrigerant Side D.W.P., psig, (kPa) 450 (3102) 450 (3102) 450 (3102) 450 (3102) 450 (3102)

Water Side D.W.P., psig, (kPa) 363 (2503) 363 (2503) 363 (2503) 363 (2503) 363 (2503) Water Connections, Victaulic: In & Out, in. (mm) 3 (76) 3 (76) 3 (76) 3 (76) 3 (76) Drain & Vent, Field Field Field Field Field UNIT DIMENSIONS Length, in. (mm) 144.2 (3663) 146.7 (3726) 146.7 (3726) 149 (3784) 149 (3784) Width, in. (mm) 32 (813) 32 (813) 32 (813) 32 (813) 32 (813) Height, in. (mm) 66 (1676) 66 (1676) 66 (1676) 66 (1676) 66 (1676) UNIT WEIGHTS Operating Wt, lb., (kg) 3809 (1728) 4025 (1826) 4289 (1945) 4478 (2031) 4627 (2099) Shipping Wt, lb. (kg) 3590 (1628) 3806 (1726) 4037 (1831) 4178 (1895) 4287 (1945) Cir # 1,Opn. Charge, lb.,(kg) R-22 87 (39.3) 84 (37.9) 82 (37.0) 76 (34.3) 76 (34.3) Cir # 2,Opn. Charge, lb.,(kg) R-22 87 (39.3) 84 (37.9) 82 (37.0) 76 (34.3) 76 (34.3)



Table 11, WGZ 110 AW - 120 AW WGZ UNIT SIZE 110 120 Unit capacity @ ARI conditions tons, (kW) (1) 106.2 (373) 117.2 (411)

No. Circuits 2 2 COMPRESSORS (2) Nominal Tons 25 30 30 30 Number (2) 2 2 2 2 Unloading Steps 27 / 50 / 77 25 / 50 / 75 Oil Charge, per compressor oz. (l) 200 (5.9 200 (5.9 200 (5.9 200 (5.9)CONDENSER Number 1 1 No. Refrigerant Circuits 2 2 Diameter, in. (mm) 14 (356) 14 (356) Tube Length, in. (mm) 120 (3048) 120 (3048) Design W.P., psig (kPa): Refrigerant Side 450 (3102) 450 (3102) Water Side 232 (1599) 232 (1599) No. of Passes 2 2 Pump-Out Capacity lb., (kg) (3) 409 (185.5) 409 (185.5)

Water Connections, Victaulic: Water In & Out, in., (mm) (4) 5 (127) 5 (127) Relief Valve, Flare in., (mm) ½ (12.7) ½ (12.7) Purge Valve, Flare in. (mm) ½ (12.7) ½ (12.7) Vent & Drain, in. (mm) FPT ½ (12.7) ½ (12.7) Liquid Subcooling Integral Integral EVAPORATOR Number 1 1 No. Refrigerant Circuits 2 2 Water Volume, gallons (l) 13.9 (52.5) 13.9 (52.5) Refrigerant Side D.W.P., psig, (kPa) 450 (3102) 450 (3102)

Water Side D.W.P., psig, (kPa) 363 (2503) 363 (2503) Water Connections, Victaulic: In & Out, in. (mm) 3 (76) 3 (76) Drain & Vent, Field Field UNIT DIMENSIONS Length, in. (mm) 149 (3785) 149 (3785) Width, in. (mm) 32 (813) 32 (813) Height, in. (mm) 66 (1677) 66 (1677) UNIT WEIGHTS Operating Wt, lb., (kg) 4828 (2190) 5010 (2273) Shipping Wt, lb. (kg) 4488 (2036) 4670 (2118) Cir #1,Opn. Charge, lb., (kg) R-22 85 (39) 85 (39) Cir #2,Opn. Charge, lb., (kg) R-22 85 (39) 85 (39)



AA Remote Condenser Table 12, WGZ-030AA - WGZ-055AA WGZ UNIT SIZE 030 035 040 045 050 055 Cap @ 44°F LWT , 125°F SDT tons, (kW)

29 (103) 31.6 (112) 36.6 (130) 40.7 (144) 44.7 (158) 49.8 (177)

No. Circuits 2 2 2 2 2 2 COMPRESSORS Nominal Tons 7.5 9 9 9 10 10 13 10 13 13 13 15 Number (Note 1) 2 2 2 2 2 2 2 2 2 2 2 2 Unloading Steps, % 27 / 50 / 77 25 / 50 / 75 25 / 50 / 75 28 / 50 / 78 25 / 50 / 75 27 / 50 / 77 Oil Charge, per compressor oz, (l) 140 (4.1) 140 (4.1) 140 (4.1) 140 (4.1) 140 (4.1) 140 (4.1)

Discharge Valve In., (mm) 1.125 (28) 1.125 (28) 1.125 (28) 1.125 (28) 1.125 (28) 1.125 (28) 1.375 (35)

EVAPORATOR No. Refrigerant Circuits 2 2 2 2 2 2 Water Volume, gallons, (l) 3.9 (14.7) 4.3 (16.4) 5 (18.9) 5.7 (21.4) 6.3 (23.9) 7.2 (27.3) Refrig. Side D.W.P. Psig, (kPa) 450 (3102) 450 (3102) 450 (3102) 450 (3102) 450 (3102) 450 (3102) Water Side D.W.P. Psig, (kPa) 363 (2503) 363 (2503) 363 (2503) 363 (2503) 363 (2503) 363 (2503) Water Connections, Victaulic: Inlet & Outlet, in., (mm) (1) 3 (76) 3 (76) 3 (76) 3 (76) 3 (76) 3 (76) Drain & Vent Field Field Field Field Field Field UNIT DIMENSIONS Length In., (mm) 122.4 (3109) 122.4 (3109) 122.4 (3109) 122.4 (3109) 122.4 (3109) 123.4 (3134) Width In., (mm) 32 (813) 32 (813) 32 (813) 32 (813) 32 (813) 32 (813) Height In., (mm) 63.5 (1613) 63.5 (1613) 63.5 (1613) 63.5 (1613) 63.5 (1613) 63.5 (1613) UNIT WEIGHTS Operating Weight, lb., (kg) 2169 (983) 2211 (1002) 2263 (1025) 2335 (1058) 2376 (1076) 2510 (1137) Shipping Weight, lb., (kg) 2248 (1018) 2285 (1035) 2331 (1056) 2392 (1084) 2424 (1098) 2558 (1159) Holding Charge, lb., (kg) R-22 Per Circuit 6.0 (2.7) 6.1 (2.8) 6.4 (2.9) 6.6 (3) 7.0 (3.2) 9.7 (4.4)

Table 13, WGZ-060AA - WGZ-100AA WGZ UNIT SIZE 060 070 080 090 100 Cap @ 44°F LWT , 125°F SDT tons, (kW) 54.9 (195) 62.1 (220) 73.0 (256) 80.0 (281) 87.5 (307)

No. Circuits 2 2 2 2 2 COMPRESSORS Nominal Horsepower 15 15 15 20 20 20 20 25 25 25 Number (3) 2 2 2 2 2 2 2 2 2 2 Unloading Steps, % 25 / 50 / 75 28 / 50 / 78 25 / 50 / 75 27 / 50 / 77 25 / 50 / 75 Oil Charge oz 140 (4.1) 140 (4.1) 148 (4.3) 148 (4.3) 148 (4.3) 148 (4.3) 200 (5.9) 200 (5.9) 200 (5.9)EVAPORATOR No. Refrigerant Circuits 2 2 2 2 2 Water Volume, gallons (l) 8.1 (30.7 9.2 (34.9) 10.8 (40.7) 12.8 (48.3) 13.9 (52.5) Refrigerant Side D.W.P., psig, (kPa) 450 (3102) 450 (3102) 450 (3102) 450 (3102) 450 (3102)

Water Side D.W.P., psig, (kPa) 363 (2503) 363 (2503) 363 (2503) 363 (2503) 363 (2503)

Water Connections: Inlet & Outlet, in. (mm) (2) 3 (76) 3 (76) 3 (76) 3 (76) 3 (76) Drain & Vent Field Field Field Field Field UNIT DIMENSIONS Length, in. (mm) 140 (3556) 142.5 (3620) 142.5 (3620) 144.75 (3677) 144.75 (3677) Width, in. (mm) 32 (813) 32 (813) 32 (813) 32 (813) 32 (813) Height, in. (mm) 66 (1676) 66 (1676) 66 (1676) 66 (1676) 66 (1676) UNIT WEIGHTS Operating Wt, lb., (kg) 2784 (1261) 2953 (1338) 3164 (1433) 3280 (1486) 3345 (1515) Shipping Wt, lb. (kg) 2833 (1283) 3001 (1359) 3198 (1449) 3295 (1493) 3238 (1468) Holding Charge, lb. (kg) R-22 10.0 (4.5) 10.5 (4.7) 11.1 (5) 11.8 (5.4) 12.3 (5.6) Notes:

1. All units have two compressors per circuit in parallel. 2. Condenser and field piping not included


Table 14, WGZ-100AA – WGZ-120AA WGZ UNIT SIZE 110 120 Cap @ 44°F LWT , 125°F SDT tons, (kW) 99.1 (348) 109.2 (384)

No. Circuits 2 2 COMPRESSORS Nominal Horsepower 25 30 30 30 Number (3) 2 2 2 2 Unloading Steps, % 27 / 50 / 77 25 / 50 / 75 Oil Charge oz 200 (5.9) 200 (5.9) 200 (5.9) 200 (5.9)EVAPORATOR No. Refrigerant Circuits 2 2 Water Volume, gallons (l) 13.9 (52.5) 13.9 (52.5) Refrigerant Side D.W.P., psig, (kPa) 450 (3102) 450 (3102)

Water Side D.W.P., psig, (kPa) 363 (2503) 363 (2503)

Water Connections: Inlet & Outlet, in. (mm) (2) 3 (76) 3 (76) Drain & Vent Field Field UNIT DIMENSIONS Length, in. (mm) 144.8 (3677) 144.8 (3677) Width, in. (mm) 32 (813) 32 (813) Height, in. (mm) 66 (1676) 66 (1676) UNIT WEIGHTS Operating Wt, lb., (kg) 3345 (1515) 3405 (1544) Shipping Wt, lb. (kg) 3238 (1468) 3298 (1495) Cir #1 Hldg Chg, lb. (kg) R-22Per Circuit 15 (6.8) 15 (6.8)

Notes: 1. Victaulic 2. Condenser and field piping not included 3. All units have two compressors per circuit in parallel.

Operating Limits • Maximum allowable condenser water pressure is 232 psig (1599 kPa). • Maximum allowable cooler water pressure is 363 psig (2509 kPa). • Maximum design saturated discharge temperature is 140°F (60°C). • Maximum allowable water temperature to cooler in a non-operating cycle is 100°F

(37.8°C). Maximum entering water temperature for operating cycle is 90°F (32.2°C) (during system changeover from heating to cooling cycle).

• Minimum leaving water temperature from the cooler without freeze protection is 40°F (4.4°C).

• Minimum entering tower condenser water temperature is 60°F (15.6°C). • For remote air-cooled condensers, the temperature difference between the saturated

discharge temperature and the outside air temperature (TD) must be between 15 and 30 degrees F and the saturated discharge temperature cannot exceed 125°F.


Components Figure 19, Compressor Locations

4 2 3 1

Circuit 2 Circuit 1 Control Panel

EvaporatorEvaporator andCondenserConnections

Table 15, Major Components System #1 System #2 Expansion Valve Unit

Size Comp. #1 Comp. #3 Comp. #2 Comp. #4

Evap. Vessel

Size

Cond. Vessel

Size System #1 System #2

030 ZR90K3 ZR90K3 ZR11M3 ZR11M3 AC250-70DQ C1010-046 OVE-20-CP100 OVE-20-CP100035 ZR11M3 ZR11M3 ZR11M3 ZR11M3 AC250-78DQ C1010-046 OVE-20-CP100 OVE-20-CP100040 ZR12M3 ZR12M3 ZR12M3 ZR12M3 AC250-90DQ C1010-058 OVE-20-CP100 OVE-20-CP100045 ZR12M3 ZR12M3 ZR16M3 ZR16M3 AC250-102DQ C1010-058 OVE-30-CP100 OVE-30-CP100050 ZR16M3 ZR16M3 ZR16M3 ZR16M3 AC250-114DQ C1010-070 OVE-30-CP100 OVE-30-CP100055 ZR16M3 ZR16M3 ZR19M3 ZR19M3 AC250-130DQ C1010-070 OVE-30-CP100 Y929-VCP100 060 ZR19M3 ZR19M3 ZR19M3 ZR19M3 AC250-146DQ C1410-078 Y929-VCP100 Y929-VCP100 070 ZR19M3 ZR19M3 ZR250KC ZR250KC AC250-166DQ C1410-090 OVE-40-CP100 OVE-40-CP100080 ZR250KC ZR250KC ZR250KC ZR250KC AC250-194DQ C1410-098 OVE-40-CP100 OVE-40-CP100090 ZR250KC ZR250KC ZR300KC ZR300KC AC250-230DQ C1410-110 OVE-55-CP100 OVE-55-CP100100 ZR300KC ZR300KC ZR300KC ZR300KC AC250-250DQ C1410-122 OVE-55-CP100 OVE-55-CP100110 ZR300KC ZR300KC ZR380KC ZR380KC AC250-250DQ C1410-122 OVE-55-CP100 OVE-70-CP100120 ZR380KC ZR380KC ZR380KC ZR380KC AC250-250DQ C1410-122 OVE-70-CP100 OVE-70-CP100


Wiring Field Wiring, Power The WGZ “A” vintage chillers are built standard with compressor contractors and power terminal block, designed for single power supply to the unit. Optional power connections include a non-fused disconnect switch mounted in the control box or multi-point power connection.

A factory installed control circuit transformer is standard. Optionally, a field-installed control power source can be wired to the unit.

Circuit breakers for backup compressor short circuit protection are standard on all units.

Wiring and conduit selections must comply with the National Electrical Code and/or local requirements.

An open fuse indicates a short, ground, or overload. Before replacing a fuse or restarting a compressor, the trouble must be found and corrected. Tables in the Electrical Data section (page 35) give specific information on recommended wire sizes.

Unit power inlet wiring must enter the control box (right side) through a patch plate provided for field terminating conduit. (Refer to control panel dimension drawings for general location of power inlet and components.)

NOTE: Use only copper conductors in main terminal block. Terminations are sized for copper only.

Field Wiring, Control A factory-mounted control transformer is provided to supply the correct control circuit voltage.

The transformer power leads are connected to the power block PB1 or disconnect switch DS1.

Interlock Wiring, Condenser Pump Starter or Air Cooled Condenser Fan Starter Provisions are made for interlocking a condenser pump starter, tower fans, a tower bypass valve, or up to eight air-cooled condenser fan contactors to be controlled by the MicroTech II unit controller. Condenser fan operation can also be controlled by pressure switches supplied with the condenser. Coil voltage must be 115 volts with a maximum of 20 VA.

An evaporator and condenser (water-cooled units only) flow switch is necessary on all units. It is also advisable to wire a chilled water pump interlock in series with the flow switch for additional freeze protection.

Ambient Air Sensor Units with a remote air-cooled condenser will have an outdoor air sensor furnished with the unit, inside the control panel and wired to the correct terminals. It must be installed outdoors in a location that will give the true outdoor temperature that the condenser coils will see. Splicing of the sensor lead may be required. The sensor must be installed for the unit to operate.

Optional Remote Interface Panel The box containing the optional remote interface panel will have installation instructions, IOM- MT II Remote, in it.


Unit Configuration

The chiller unit has two refrigerant circuits, two tandem scroll compressors (total of four), a single two-circuited brazed plate evaporator, a single two-circuited water-cooled condenser, interconnecting refrigerant piping and a control panel with associated sensors and transducers.

Figure 20, Schematic Piping Diagram (One of Two Circuits)

Comp#2

Comp#1

Condenser CondenserWater

EvaporatorChilledWater

S

F-D

T

S S

CV

SP

P1

LWT

T

T

Legend:

Temperature Sensor

Pressure Transducer

Pressure (High Pressure Cutout)

Temperataure Sensor, LeavingChilled Water Control

TT

TP

P1

LWT

Relief Valve

Schrader Fitting

Thermal Expansion Valve

Sight Glass / Moisture Indicator

Charging Valve

TS

CV

SSolenoid Valve

F-D Filter-Drier

Angle Valve

Ball Valve


Electrical Data

Table 16, Compressor Amp Draw, WGZ 030 - WGZ 120 Standard With External OL's Locked Rotor Amps

Rated Load Amps Rated Load Amps Across-The-Line Per Compressor Per Compressor Per Compressor

( 2 Compr./Circuit) ( 2 Compr./Circuit) ( 2 Compr./Circuit)

WGZ Unit Size

Voltage Freq. (Hertz)

Circuit 1 Circuit 2 Circuit 1 Circuit 2 Circuit 1 Circuit 2 208 23.7 29.9 23.2 26.4 189 232 230 23.7 29.9 21.6 24.0 189 232 460 12.5 15.3 11.2 12.0 99 125

030

575

60

9.1 11.6 8.8 9.6 74 100 208 29.9 29.9 26.4 26.4 232 232 230 29.9 29.9 24.0 24.0 232 232 460 15.3 15.3 12.0 12.0 125 125 035

575

60

11.6 11.6 9.6 9.6 100 100 208 33.6 33.6 29.6 29.6 278 278 230 33.6 33.6 27.2 27.2 278 278 460 16.5 16.5 13.6 13.6 127 127 040

575

60

13.7 13.7 11.2 11.2 100 100 208 33.6 41.0 29.6 34.4 278 350 230 33.6 41.0 27.2 31.2 278 350 460 16.5 21.8 13.6 15.2 127 158 045

575

60

13.7 17.3 11.2 12.8 100 125 208 41.0 41.0 34.4 34.4 350 350 230 41.0 41.0 31.2 31.2 350 350 460 21.8 21.8 15.2 15.2 158 158 050

575

60

17.3 17.3 12.8 12.8 125 125 208 41.0 48.1 34.4 40.8 350 425 230 41.0 48.1 31.2 36.8 350 425 460 21.8 23.7 15.2 18.4 158 187 055

575

60

17.3 21.2 12.8 15.2 125 148 208 48.1 48.1 40.8 40.8 425 425 230 48.1 48.1 36.8 36.8 425 425 460 23.7 23.7 18.4 18.4 187 187 060

575

60

21.2 21.2 15.2 15.2 148 148 208 48.1 73.1 40.8 56.8 425 505 230 48.1 73.1 36.8 51.2 425 505 460 23.7 30.1 18.4 24.0 187 225 070

575

60

21.2 24.4 15.2 148 180 208 73.1 73.1 56.8 56.8 505 505 230 73.1 73.1 51.2 51.2 505 505 460 30.1 30.1 24.0 24.0 225 225 080

575

60

24.4 24.4 19.2 19.2 180 180 208 73.1 78.9 56.8 63.2 505 500 230 73.1 78.9 51.2 57.6 505 500 460 30.1 38.5 24.0 28.8 225 250 090

575

60

24.4 30.8 19.2 23.2 180 198 208 78.9 78.9 63.2 63.2 500 500 230 78.9 78.9 57.6 57.6 500 500 460 38.5 38.5 28.8 28.8 250 250 100

575

60

30.8 30.8 23.2 23.2 198 198 208 78.9 100 63.2 80.8 500 640 230 78.9 100 57.6 72.8 500 640 460 38.5 48.7 28.8 36.8 250 310 110

575

60

30.8 39.0 23.2 29.6 198 248 208 100 100 80.8 80.8 640 640 230 100 100 72.8 72.8 640 640 460 48.7 48.7 36.8 36.8 310 310 120

575

60

39.0 39.0 29.6 29.6 248 248 NOTES: 1. Compressor RLA values are for wire sizing purposes only and do not reflect normal operating current draw. 2. External Overloads only available on Units with Single Power Supply and Water Cooled Condensers


Table 17, Wire Sizing Amps, WGZ 030 - WGZ 120 Minimum Circuit Ampacity (MCA) (1)

Single Point Single Point Multiple Point Power Supply (2) Power Supply (2) Power Supply (3)

WGZ Unit Size

Voltage Freq. (Hertz)

Without Ext OL's With Ext OL's Circuit 1 Circuit 2 208 115 106 54 68 230 115 97 54 68 460 60 49 29 35

030

575

60

45 39 21 27 208 128 112 68 68 230 128 102 68 68 460 66 51 35 35

035

575

60

50 41 27 27 208 143 126 76 76 230 143 116 76 76 460 71 58 38 38

040

575

60

59 48 31 31 208 160 137 76 93 230 160 125 76 93 460 83 61 38 50

045

575

60

67 51 31 39 208 175 146 93 93 230 175 133 93 93 460 93 65 50 50

050

575

60

74 54 39 39 208 190 161 93 109 230 190 145 93 109 460 97 72 50 54

055

575

60

82 60 39 48 208 205 173 109 109 230 205 156 109 109 460 101 78 54 54

060

575

60

90 65 48 48 208 261 209 109 165 230 261 189 109 165 460 115 91 54 68

070

575

60

97 74 48 55 208 311 241 165 165 230 311 218 165 165 460 128 102 68 68

080

575

60

104 82 55 55 208 324 256 165 178 230 324 232 165 178 460 147 113 68 87

090

575

60

118 91 55 70 208 336 269 178 178 230 336 245 178 178 460 164 122 87 87

100

575

60

131 99 70 70 208 383 308 178 225 230 383 279 178 225 460 187 141 87 110

110

575

60

150 113 70 88 208 425 343 225 225 230 425 309 225 225 460 207 156 110 110

120

575

60

166 126 88 88 NOTES: 1. Unit wire sizing amps are equal to 125% of the largest compressor-motor RLA plus 100% of RLA of all other loads in the

circuit including control transformer. 2. Single point power supply requires a single fused disconnect to supply electrical power to the unit. 3. Multiple point power supply requires two independent power circuits with separate fused disconnects. (Two compressor

circuits, control circuit will be wired to Circuit #1 from the factory)


Table 18, Fuse Sizing, WGZ 030 - WGZ 120 Recommended Fuse Size (1) Maximum Fuse Size (2)

Single Point without OL’s

Single Point- with/OL's

Power Supply Power Supply

Multiple Point Power Supply

Multiple Point Power Supply

WGZ Unit Size

Voltage 3-Phase

Freq. (Hertz)

Total Unit Total Unit Cir. 1 Cir. 2

Single Point without OL’sPower Supply

Total Unit

Single Point-with OL's

Power Supply

Total Unit Cir. 1 Cir. 2

208 125 125 70 90 125 125 70 90 230 125 125 70 90 125 125 70 90 460 70 70 40 45 70 70 40 45

030

575

60

50 50 25 35 50 50 25 35 208 125 125 90 90 150 125 90 90 230 125 125 90 90 150 125 90 90 460 70 60 45 45 80 60 45 45

035

575

60

50 50 35 35 60 50 35 35 208 175 150 100 100 175 150 100 100 230 175 125 100 100 175 125 100 100 460 80 70 50 50 80 70 50 50

040

575

60

70 60 40 40 70 60 40 40 208 200 150 100 125 200 150 100 125 230 200 150 100 125 200 150 100 125 460 100 70 50 70 100 70 50 70

045

575

60

80 60 40 50 80 60 40 50 208 200 175 125 125 200 175 125 125 230 200 150 125 125 200 150 125 125 460 110 70 70 70 110 70 70 70

050

575

60

90 60 50 50 90 60 50 50 208 225 200 125 150 225 200 125 150 230 225 175 125 150 225 175 125 150 460 110 90 70 70 110 90 70 70

055

575

60

100 70 50 60 100 70 50 60 208 225 200 150 150 250 200 150 150 230 225 175 150 150 250 175 150 150 460 125 90 70 70 125 90 70 70

060

575

60

110 70 60 60 110 70 70 70 208 300 250 150 200 300 250 150 225 230 300 225 150 200 300 225 150 225 460 125 110 70 80 125 110 70 90

070

575

60

110 90 60 70 110 90 70 70 208 350 250 200 200 350 250 225 225 230 350 250 200 200 350 250 225 225 460 150 125 80 80 150 125 90 90

080

575

60

125 100 70 70 125 100 70 70 208 400 300 200 250 400 300 225 250 230 400 250 200 250 400 250 225 250 460 175 125 80 110 175 125 90 125

090

575

60

125 110 70 80 125 110 70 90 208 400 300 250 250 400 300 250 250 230 400 300 250 250 400 300 250 250 460 200 150 110 110 200 150 125 125

100

575

60

150 110 80 80 150 110 90 90 208 450 350.0 250 300 500 350.0 250 350 230 450 350.0 250 300 500 350.0 250 350 460 225 150.0 110 125 225 150.0 125 150

110

575

60

175 125.0 80 110 175 125.0 90 125 208 500 400 300 300 500 400 350 350 230 500 350 300 300 500 350 350 350 460 250 175.0 125 125 250 175.0 150 150

120

575

60

200 150.0 110 110 200 150.0 125 125

NOTES: 1. "Recommended Fuse Size" are selected at approximately 175% of the largest compressor RLA, plus 100% of all other circuit load. 2. "Maximum Fuse Sizes" are selected at approximately 225% of the largest compressor RLA, plus 100% of all other loads.


Table 19, Wire Sizing, WGZ 030 - WGZ 120 Single Point Power Supply

Without External OL's With External OL's Multiple Point Power Supply

Circuit #1 Circuit #2 WGZ Unit Size

Voltage 3-Phase

Freq. (Hertz) No. of

Power Wires

Wire Size

No. of Power Wires

Wire Size No. Of

Wires Wire Size

No. Of Wires

Wire Size

208 3 2 GA 3 2 GA 3 6 GA 3 4 GA 230 3 2 GA 3 3 GA 3 6 GA 3 4 GA 460 3 6 GA 3 8 GA 3 10 GA 3 10 GA

030

575

60

3 8 GA 3 8 GA 3 12 GA 3 10 GA 208 3 1 GA 3 2 GA 3 4 GA 3 4 GA 230 3 1 GA 3 2 GA 3 4 GA 3 4 GA 460 3 4 GA 3 6 GA 3 10 GA 3 10 GA

035

575

60

3 8 GA 3 8 GA 3 10 GA 3 10 GA 208 3 1/0 3 1 GA 3 4 GA 3 4 GA 230 3 1/0 3 1 GA 3 4 GA 3 4 GA 460 3 4 GA 3 6 GA 3 8 GA 3 8 GA

040

575

60

3 6 GA 3 8 GA 3 10 GA 3 10 GA 208 3 2/0 3 1/0 3 4 GA 3 3 GA 230 3 2/0 3 1 GA 3 4 GA 3 3 GA 460 3 4 GA 3 6 GA 3 8 GA 3 8 GA

045

575

60

3 4 GA 3 6 GA 3 10 GA 3 8 GA 208 3 2/0 3 1/0 3 3 GA 3 3 GA 230 3 2/0 3 1/0 3 3 GA 3 3 GA 460 3 3 GA 3 6 GA 3 8 GA 3 8 GA

050

575

60


055

575

60


060

575

60

3 3 GA 3 6 GA 3 8 GA 3 8 GA 208 3 300 kcmil 3 4/0 3 2 GA 3 2/0 230 3 300 kcmil 3 3/0 3 2 GA 3 2/0 460 3 2 GA 3 3 GA 3 6 GA 3 4 GA

070

575

60

3 3 GA 3 4 GA 3 8 GA 3 6 GA 208 3 400 kcmil 3 250 kcmil 3 2/0 3 2/0 230 3 400 kcmil 3 4/0 3 2/0 3 2/0 460 3 1 GA 3 2 GA 3 4 GA 3 4 GA

080

575

60

3 2 GA 3 4 GA 3 6 GA 3 6 GA 208 3 400 kcmil 3 300 kcmil 3 2/0 3 3/0 230 3 400 kcmil 3 250 kcmil 3 2/0 3 3/0 460 3 1/0 3 2 GA 3 4 GA 3 3 GA

090

575

60

3 1 GA 3 3 GA 3 6 GA 3 4 GA 208 3 500 kcmil 3 300 kcmil 3 3/0 3 3/0 230 3 500 kcmil 3 250 kcmil 3 3/0 3 3/0 460 3 2/0 3 1 GA 3 3 GA 3 3 GA

100

575

60

3 1/0 3 3 GA 3 4 GA 3 4 GA 208 6 250 kcmil 3 350 kcmil 3 3/0 3 4/0 230 6 250 kcmil 3 300 kcmil 3 3/0 3 4/0 460 3 3/0 3 1/0 3 3 GA 3 2 GA

110

575

60

3 1/0 3 2 GA 3 4 GA 3 3 GA 208 6 300 kcmil 3 500 kcmil 3 4/0 3 4/0 230 6 300 kcmil 3 350 kcmil 3 4/0 3 4/0 460 3 4/0 3 2/0 3 2 GA 3 2 GA

120

575

60

3 2/0 3 1 GA 3 3 GA 3 3 GA


Table 20, Single Point Connection Sizing, WGZ 030 - WGZ 120 Single Point Power Supply Disconnect Switch WGZ

Size Voltage 3-Phase

Freq. (Hertz) Size (1) Connection (3) Size (2) Connection (3)

208 175 14 GA - 2/0 125 3GA - 3/0 230 175 14 GA - 2/0 125 3GA - 3/0 460 175 14 GA - 2/0 125 3GA - 3/0

030

575

60

175 14 GA - 2/0 125 3GA - 3/0 208 175 14 GA - 2/0 250 6GA - 350 kcmil 230 175 14 GA - 2/0 250 6GA - 350 kcmil 460 175 14 GA - 2/0 125 3GA - 3/0

035

575

60

175 14 GA - 2/0 125 3GA - 3/0 208 175 14 GA - 2/0 250 6GA - 350 kcmil 230 175 14 GA - 2/0 250 6GA - 350 kcmil 460 175 14 GA - 2/0 125 3GA - 3/0

040

575

60

175 14 GA - 2/0 125 3GA - 3/0 208 335 6 GA - 400kcmil 250 6GA - 350 kcmil 230 335 6 GA - 400kcmil 250 6GA - 350 kcmil 460 175 14 GA - 2/0 125 3GA - 3/0

045

575

60


050

575

60


055

575

60


060

575

60

175 14 GA - 2/0 125 3GA - 3/0 208 335 6 GA - 400kcmil 400 (2) 3/0 - 500 kcmil 230 335 6 GA - 400kcmil 400 (2) 3/0 - 500 kcmil 460 175 14 GA - 2/0 125 3GA - 3/0

070

575

60

175 14 GA - 2/0 125 3GA - 3/0 208 760 (2) 2 GA - 500kcmil 400 (2) 3/0 - 500 kcmil 230 760 (2) 2 GA - 500kcmil 400 (2) 3/0 - 500 kcmil 460 335 6 GA - 400kcmil 250 6GA - 350 kcmil

080

575

60

335 6 GA - 400kcmil 125 3GA - 3/0 208 760 (2) 2 GA - 500kcmil 400 (2) 3/0 - 500 kcmil 230 760 (2) 2 GA - 500kcmil 400 (2) 3/0 - 500 kcmil 460 335 6 GA - 400kcmil 250 6GA - 350 kcmil

090

575

60

335 6 GA - 400kcmil 250 6GA - 350 kcmil 208 760 (2) 2 GA - 500kcmil 400 (2) 3/0 - 500 kcmil 230 760 (2) 2 GA - 500kcmil 400 (2) 3/0 - 500 kcmil 460 335 6 GA - 400kcmil 250 6GA - 350 kcmil

100

575

60


110

575

60


120

575

60

335 6 GA - 400kcmil 250 6GA - 350 kcmil NOTES: 1. "Size" is the maximum amperage rating for the terminals or the main electrical device. 2. "Size" is the disconnect part number and not the amperage rating for the terminals or the main electrical device. 3. "Connection" is the range of wire sizes that the terminals on the electrical device will accept.


Table 21, Multiple Point Connection Sizing, WGZ 030 - WGZ 120 Multiple Point - Circuit #1 Multiple Point - Circuit #2

Power Block Disconnect Switch Power Block Disconnect Switch WGZ Unit Size

Voltage 3-Phase

Freq. (Hertz)

Size (1) Connection (3) Size (2) Connection (3) Size (1) Connection (3) Size (2) Connection (3)208 175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0 230 175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0 460 175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0

030

575

60

175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0 208 175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0 230 175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0 460 175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0

035

575

60


040

575

60


045

575

60


050

575

60


055

575

60


060

575

60

175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0 208 175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 250 6 GA - 350kcmil230 175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 250 6 GA - 350kcmil460 175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0

070

575

60

175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0 208 175 14 GA - 2/0 250 6 GA - 350kcmil 175 14 GA - 2/0 250 6 GA - 350kcmil230 175 14 GA - 2/0 250 6 GA - 350kcmil 175 14 GA - 2/0 250 6 GA - 350kcmil460 175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0

080

575

60

175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0 208 175 14 GA - 2/0 250 6 GA - 350kcmil 335 6 GA - 400kcmil 250 6 GA - 350kcmil230 175 14 GA - 2/0 250 6 GA - 350kcmil 335 6 GA - 400kcmil 250 6 GA - 350kcmil460 175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0

090

575

60

175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0 208 335 6 GA - 400kcmil 250 6 GA - 350kcmil 335 6 GA - 400kcmil 250 6 GA - 350kcmil230 335 6 GA - 400kcmil 250 6 GA - 350kcmil 335 6 GA - 400kcmil 250 6 GA - 350kcmil460 175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0

100

575

60

175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0 208 335 6 GA - 400kcmil 250 6 GA - 350kcmil 335 6 GA - 400kcmil 250 6 GA - 350kcmil230 335 6 GA - 400kcmil 250 6 GA - 350kcmil 335 6 GA - 400kcmil 250 6 GA - 350kcmil460 175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0

110

575

60

175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0 208 335 6 GA - 400kcmil 250 6 GA - 350kcmil 335 6 GA - 400kcmil 250 6 GA - 350kcmil230 335 6 GA - 400kcmil 250 6 GA - 350kcmil 335 6 GA - 400kcmil 250 6 GA - 350kcmil460 175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0 120

575

60

175 14 GA - 2/0 125 3 GA - 3/0 175 14 GA - 2/0 125 3 GA - 3/0 NOTES: 1. "Size" is the maximum amperage rating for the terminals or the main electrical device. 2. "Size" is the disconnect part number and not the amperage rating for the terminals or the main electrical device. 3. "Connection" is the range of wire sizes that the terminals on the electrical device will accept.


Field Wiring Diagram Figure 21, WGZ 030AW – 120AW Field Wiring Diagram

FIELD WIRING FOR WGZ030-120A

DWG. 330538901 REV.0D

PACKAGE/ WITH CONDENSER WITH MICROTECH CONTROLLER

TO COMPRESSOR(S)AND FAN MOTORS

DISCONNECT(BY OTHERS)

3 PHASE

POWER

120VACCONTROL POWER

GND LUGUNIT MAIN

TERMINAL BLOCK

FUSED CONTROLCIRCUIT TRANSFORMER

OPTION

120 VAC

TB1

TB1-20

CHW PUMP RELAY (BY OTHERS)120 VAC 1.0 AMP MAX


N

FIELDSUPPLIED

OPTION 10AFUSE

(BY OTHERS)CONTROLCIRCUIT

FUSE2

1

N120 VAC

14

11

NOTE: ALL FIELD WIRING TO BEINSTALLED AS NEC CLASS 1WIRING SYSTEM WITH CONDUCTORRATED 600 VOLTS

SUPPLY

GND

ALARM BELL RELAY

FACTORY SUPPLIED ALARMFIELD WIRED

ALARMBELL

OPTION 10

15

CONTROLLER

70

68

HOT GAS BYPASS #2 SOLENOID24 VAC 1.0 AMP MAX.

70

67

HOT GAS BYPASS #1 SOLENOID24 VAC 1.0 AMP MAX.

65

63

LIQUID LINE #2 SOLENOID24 VAC 1.5 AMP MAX.

LESSEVAPORATORONLY

24 VAC

N

24 VAC

N

24 VAC

N

TB2

ICE MODE SWITCH(BY OTHERS)

51

52

42

60

40

53

43

55

49

50

ALARM BELLRELAY

ALARM BELL OPTION

BELL1 2

COM NO

AUTO

TIMECLOCK OFF

ON

MANUAL

AUTO OFF

ON

MANUAL

REMOTE STOPSWITCH

(BY OTHERS)

IF REMOTE STOPCONTROL IS USED,REMOVE LEAD 897FROM TERM. 40 TO 53.

897

4-20MA FOREVAP. WATER RESET

(BY OTHERS)

+

-

4-20MA FORDEMAND LIMIT(BY OTHERS)

+

GND

-

33

44

CHW FLOW SWITCH---MANDATORY–-

(BY OTHERS)NOR. OPEN PUMP AUX. CONTACTS (OPTIONAL)

41

54

CDW FLOW SWITCH---MANDATORY–-

(BY OTHERS)NOR. OPEN PUMP AUX. CONTACTS (OPTIONAL)

65

62

LIQUID LINE #1 SOLENOID24 VAC 1.5 AMP MAX.

N

24 VAC

N

N

120 VAC

120 VAC

120 VAC

120 VAC

CDW PUMP RELAY (BY OTHERS)120 VAC 1.0 AMP MAX

TOWER FAN #1 COIL (BY OTHERS)120 VAC 1.0 AMP MAX

TOWER FAN #2 COIL (BY OTHERS)120 VAC 1.0 AMP MAX

TB1-12

J15-NO8

TB1-12

J16-NO9

J16-NO10

TB3-90

TB3-91

TB3-92

79

80 N0-10 VDC

77

78 N0-10 VDC

COOLING TOWER BYPASS(BY OTHERS)


TB3


Figure 22, WGZ 030AA – 120AA Field Wiring Diagram (Remote Condenser)

FIELD WIRING FOR WGZ030-120A(REMOTE CONDENSER)

WITH MICROTECH CONTROLLERDWG. 330539001 REV.0D

TB2

ICE MODESWITCH

(BY OTHERS)

TO COMPRESSOR(S)AND FAN MOTORS


3 PHASEPOWER

120VACCONTROL POWER

UNIT MAINTERMINAL BLOCK

FUSED CONTROLCIRCUIT

TRANSFORMEROPTION

120 VAC

TB1

TB1-20

CHW PUMP RELAY(BY OTHERS)

120 VAC 1.0 AMP MAX


N

FIELDSUPPLIED

OPTION10A

FUSE

(BY OTHERS)

CONTROLCIRCUITFUSE

120 VAC

GND

ALARM BELL RELAY

FACTORY SUPPLIED ALARMFIELD WIRED

ALARM BELLOPTION

51

52

10

15

2

1

42

60

40

53

43

55

33

44

37

49

50

38

ALARM BELLRELAY

ALARM BELL OPTION

BELL1 2

COM NO

NOTE: ALL FIELD WIRING TO BEINSTALLED AS NEC CLASS 1WIRING SYSTEM WITH CONDUCTORRATED 600 VOLTS

SUPPLY

AUTOTIME

CLOCK OFF

ON

MANUAL

AUTO OFF

ON

MANUAL

REMOTE STOPSWITCH

(BY OTHERS)

IF REMOTE STOPCONTROL IS USED,REMOVE LEAD 897FROM TERM. 40 TO 53.

897

CHW FLOW SWITCH---MANDATORY–-

(BY OTHERS)

NOR. OPEN PUMP AUX.CONTACTS (OPTIONAL)

4-20MA FORCHW RESET(BY OTHERS)

+

GND

-

4-20MA FORDEMAND LIMIT(BY OTHERS)

+

GND

-

CONTROLLER

NOTE: CONDENSERFAN MOTORS CAN ALSOBE CONTROLLED BYPRESSURE SWITCHESON THE CONDENSER.

J18-NO13

J22-NO16

J22-NO17

J22-NO18

J16-NO9

J16-NO10

J16-NO11

120 VAC

120 VAC

120 VAC

120 VAC

120 VAC

120 VAC

120 VAC

FAN MOTOR #1 COIL (BY OTHERS)120 VAC 1.0 AMP MAX.

NTB1-12

J15-NO8120 VAC








TB3-90

TB3-91

TB3-94

TB3-92

TB3-93

TB3-95

TB3-96

TB3-97

N120 VAC

14

11

N0-10 VDC

77

78

N79

80

TB3



0-10 VDC

GND LUG


Notes for “Electrical Data Single Point” Power: 1. If a separate 115V power supply is used for the control circuit, then the wire sizing amps

is 10 amps for all unit sizes. 2. Recommended power lead wire sizes for 3 conductors per conduit are based on 100%

conductor ampacity in accordance with NEC. Voltage drop has not been included. Therefore, it is recommended that power leads be kept short. All terminal block connections must be made with copper (type THW) wire.

3. The recommended power lead wire sizes are based on an ambient temperature of 86°F (30°C). Ampacity correction factors must be applied for other ambient temperatures. Refer to the National Electrical Code Handbook.

4. Must be electrically grounded according to national and local electrical codes.

Voltage Limitations: 1. Within ± 10 percent of nameplate rating

2. Voltage unbalance not to exceed 2% with a resultant current unbalance of 6 to 10 times the voltage unbalance per NEMA MG-1, 1998 Standard. This is an important restriction that must be adhered to.

Notes for “Field Wiring Data” 1. Requires a single disconnect to supply electrical power to the unit. This power supply

must either be fused or use an HACR type circuit breaker. 2. All field wiring to unit power block or optional non-fused disconnect switch must be

copper. 3. All field wire size values given in table apply to 75°C rated wire per NEC.

Supplemental Overloads Option -- Supplemental overloads option is used to reduce the required electrical service size and wire sizing to the water cooled version of WGZ chillers. The overloads reduce the electrical ratings for the compressor because water-cooled duty is less severe than air cooled duty. The overload option is only available for models with water-cooled condensers (not WGZ-AA models with air-cooled condensers) and having single point electrical power connections. Refer to the electrical data on pages 35, 37, and 38 for the reduced electrical requirements


Control Panel Layout Figure 23, Typical Control Panel

NOTES:

1. Additional space provided in the upper right section for extra components required for optional multiple point power connection and optional circuit breakers.

2. Front door has opening on top for access to the MicroTech II controller for viewing display and making keypad entries without opening the panel door.

Motor Protection Module The motor protection system consists of an external control module, located on each compressor, connected to a series of thermistors located in the motor windings and the compressor discharge port. If the windings experience an over-temperature condition or the discharge temperature is excessive, the module will trip and shut off the compressor for a 30-minute time delay.

MicroTech II Unit Controller

Terminal Strips

S1, PS1, PS2

Switches

(4) Compressor Contactors

Grounding Lug

Disconnect Switch

Space for Optional Circuit Breakers and Multi-point Connection

110V Control Transformer (CT)

(3) 24V Controller Transformers


Start-Up and Shutdown

Complete operating instructions are contained in Operating Manual OM WGZ.

Pre Start-up 1. The chilled-water system should be flushed and cleaned. Proper water treatment is

required to prevent corrosion and organic growth. 2. With main disconnect open, check all electrical connections in control panel and starter to

be sure they are tight and provide good electrical contact. Although connections are tightened at the factory, they can loosen enough in shipment to cause a malfunction.

3. Check and inspect all water piping. Make sure flow direction is correct and piping is made to correct connection on evaporator and condenser.

4. Open all water flow valves to the condenser and evaporator. 5. Flush the cooling tower and system piping to be sure the system is clean. Start evaporator

pump and manually start condenser pump and cooling tower. Check all piping for leaks. Vent the air from the evaporator and condenser water circuit, as well as from the entire water system. The cooler circuit should contain clean, treated, non-corrosive water.

6. Check to see that the evaporator water thermostat sensor is securely installed. 7. Making sure control stop switch S1 is open (off) and pumpdown switches PS1 and PS2

are on “manual pumpdown,” place the main power and control disconnect switches to “on.” This will energize the crankcase heaters. Wait a minimum of 12 hours before starting the unit.

8. Check compressor oil level. Prior to start-up, the oil level should cover at least one-third of the oil sight glass located in the equalizing line between the compressors or on the compressor.

9. Check water pressure drop across evaporator and condenser, and see that water flow is correct (on pages 15 and 16) per the design flow rates.

10. Check the actual line voltage to the unit to make sure it is the same as called for on the compressor nameplate, within + 10%, and that phase voltage unbalance does not exceed 3%. Verify that adequate power supply and capacity is available to handle load.

11. Make sure all wiring and fuses are of the proper size. Also make sure that all interlock wiring is completed per McQuay diagrams.

12. Verify that all mechanical and electrical inspections by code authorities have been completed.

13. Make sure all auxiliary load and control equipment is operative and that an adequate cooling load is available for initial start-up.

Start-up 1. Open the compressor discharge shutoff valves until backseated. Always replace valve seal

caps. 2. Open the two manual liquid line shutoff valves. 3. Check to see that the unit circuit breakers are in the “off” position. 4. Check to see that the pumpdown switches, PS1 and PS2, are in the “manual pumpdown”

position and the control system switch S1 is in the “off” position. 5. Put the main power and control circuit disconnects to the “on” position.


6. Verify crankcase heaters have operated for at least 12 hours prior to start-up. Crankcase should be warm to the touch.

7. Check that the MicroTech II controller is set to the desired chilled water temperature. 8. Start the system auxiliary equipment for the installation by turning on the time clock,

ambient thermostat and/or remote on/off switch and water pumps. 9. Check resets of all equipment protection controls. 10. Switch on the unit circuit breakers. 11. Set pumpdown switches PS1 and PS2 to “auto” for restart and normal operation. 12. Start the system by setting the system switch S1 to on. 13. After running the unit for a short time, check the oil level in each compressor crankcase,

rotation of condenser fans (if any), and check for flashing in the refrigerant sight glass. 14. After system performance has stabilized, it is necessary that the “Compressorized

Equipment Warranty Form” (Form No. 206036A) be completed to establish commencement of the warranty period. Be sure to list the pressure drop across both vessels. This form is shipped with the unit and after completion should be returned to the McQuayService Department through your sales representative.

Weekend or Temporary Shutdown Move pumpdown switches PS1 and PS2 to the “manual pumpdown” position. After the compressors have pumped down, turn off the chilled water pump. Note: With the unit in this condition, it will not restart until these switches are turned back on. The unit has one-time pumpdown. It is important that the compressors pump down before the water flow to the unit is interrupted to avoid freeze-up in the evaporator.

Leave S1 on and power to the unit so that the crankcase heaters will remain energized.

Start-up after Temporary Shutdown 1. Start the water pumps. 2. With the control system switch S1 in the “on” position, move the pumpdown switches PS1

and PS2 to the “auto pumpdown” position. 3. Observe the unit operation for a short time, noting unusual sounds or possible cycling of

compressors. 4. Check compressor crankcase heaters.

Extended Shutdown 1. Close the manual liquid line shutoff valves. 2. After the compressors have pumped down, turn off the water pumps. 3. Turn off all power to the unit. 4. Move the control service switch S1 to the “off” position. 5. Close the discharge shutoff valves on the compressor(s) and the liquid outlet valves at the

condenser. 6. Tag all opened disconnect switches to warn against start-up before opening the

compressor suction and discharge valves. 7. Drain all water from the unit evaporator, condenser, and chilled water piping if the unit is

to be shut down during the winter and exposed to below freezing temperatures. Do not leave the vessels or piping open to the atmosphere over the shutdown period.


Start-up after Extended Shutdown 1. Inspect all equipment to see that it is in satisfactory operating condition. 2. Remove all debris that has collected on the surface of the condenser coils (remote

condenser models) or check the cooling tower, if present. 3. Open the compressor discharge valves until backseated. Always replace valve seal caps. 4. Open the manual liquid line shutoff valves. 5. Check circuit breakers. They must be in the “off” position. 6. Check to see that the pumpdown switches PS1 and PS2 are in the “manual shutdown”

position and the control system switch S1 is in the “off” position. 7. Put the main power and control circuit disconnects to the “on” position. 8. Allow the crankcase heaters to operate for at least 12 hours prior to start-up. 9. Start the chilled water pump and purge the water piping as well as the evaporator in the

unit. 10. Start the system auxiliary equipment for the installation by turning on the time clock,

ambient thermostat and/or remote on/off switch. 11. Check that the MicroTech II controller is set to the desired chilled water temperature. 12. Check resets of all equipment protection controls. 13. Switch the unit circuit breakers to “on.” 14. Start the system by setting the system switch S1 to “on.”

CAUTION

Most relays and terminals in the control center are powered when S1 is closed and the control circuit disconnect is on. Therefore, do not close S1 until ready

for start-up or serious equipment damage can occur.

15. Set pumpdown switches PS1 and PS2 to the “auto pumpdown” position for restart and normal operation.

16. After running the unit for a short time, check the oil level in the compressor oil sight glass or in the compressor's equalizing lines for flashing indicating possible refrigerant in the oil (see Maintenance section beginning on page 48).


System Maintenance

General To provide smooth operation at peak capacity and to avoid damage to package components, a program of periodic inspections should be set up and followed. The following items are intended as a guide to be used during inspection and must be combined with sound refrigeration and electrical practices to provide trouble-free performance.

The liquid line sight glass/moisture indicator on all circuits must be checked to be sure that the glass is full and clear and that the moisture indicator indicates a dry condition. If the indicator shows that a wet condition exists or if bubbles show in the glass, even with a full refrigerant charge, the filter-drier element must be changed.

Water supplies in some areas can tend to foul the water-cooled condenser to the point where cleaning is necessary. The fouled condenser will be indicated by an abnormally high condenser approach temperature (saturated discharge temperature minus leaving condenser water temperature) and can result in nuisance trip-outs. To clean the condenser, mechanical cleaning or a chemical descaling solution should be used according to the manufacturer’s directions.

Systems with remote air-cooled condensers require periodic cleaning of the finned surface of the condenser coil.

Cleaning can be accomplished by using a cold water spray, brushing, vacuuming, or high-pressure air. No tools should be used that could damage the coil tubes or fins.

The compressor oil level must be checked periodically to be sure that the level is at the center of the oil sightglass located in the compressor's equalizing line or on the compressor itself. Low oil level can cause inadequate lubrication and if oil must be added, use oils referred to in the following “Compressor Lubrication” section.

A pressure tap has been provided on the liquid line downstream of the filter-drier and solenoid valve but before the expansion valve. An accurate subcooled liquid pressure and temperature can be taken here. The pressure read here could also provide an indication of excessive pressure drop through the filter-drier and solenoid valve due to a clogging filter-drier. Note: A normal pressure drop through the solenoid valve is approximately 3 psig (20.7 kPa) at full load conditions.

CAUTION

Warranty may be affected if wiring is not in accordance with specifications. A blown fuse or tripped protector indicates a short ground or overload. Before

replacing fuse or restarting compressor, the trouble must be found and corrected. It is important to have a qualified control panel electrician service

this panel. Unqualified tampering with the controls can cause serious damage to equipment and void the warranty.


DANGER

The panel is always energized to ground even when the system switch is off. To de-energize the complete panel including crankcase heaters, pull the main unit disconnect. Failure to do so can result in severe personal injury or death.

If motor or compressor damage is suspected, do not restart until qualified service personnel have checked the unit.

Electrical Terminals

WARNING To avoid injury from electric shock hazard, turn off all power and perform

lockout and tag-out of source before continuing with the following service. Note that the unit might be powered from multiple sources.

All power electrical terminals should be re-tightened every six months, as they tend to loosen due to normal heating and cooling of the wire.

Compressor Lubrication The oil level should be watched carefully upon initial start-up and regularly thereafter.

All tandem compressors on WGZ units come equipped with one or two oil equalization lines connecting the crankcase of each set of compressors in each refrigerant circuit. This allows the oil to move from one compressor crankcase to the other during normal operation, and balance between the two when the compressors are off. The oil sight glass is located in the equalization line on one circuit of the WGZ 070 and both circuits of WGZ 080 through WGZ 100. All other models have the oil sight glass in the compressor body. In either case, the oil level should be 1/4 to 1/3 of the glass.

At the present time, standard refrigerant mineral oils such as Suniso No. 3GS, Calumet R015, and Texaco WF32 oils are approved by Copeland for use in these compressors.

Oil can be added to the Copeland compressor through the oil fill hole in the crankcase. Special equipment is required to add oil and the work should be done by qualified refrigeration technicians with the proper training and equipment.

Sight glass and Moisture Indicator The refrigerant sight glasses should be observed periodically. A monthly observation should be adequate. A clear glass of liquid indicates that there is adequate refrigerant charge in the system to provide proper feed through the expansion valve. The sight glass should be clear when:

• Ambient temperature is above 75°F (23°C) • Both compressors on a circuit are running • All fans on a circuit are running

Bubbling refrigerant in the sight glass may occur at other conditions and may indicate that the system is short of refrigerant charge. Refrigerant gas flashing in the sight glass could also indicate an excessive pressure drop in the line, possibly due to a clogged filter-drier or a restriction elsewhere in the system. An element inside the sight glass indicates what moisture condition corresponds to a given element color. If the sight glass does not indicate a dry


condition after about 12 hours of operation, the unit should be pumped down and the filter-driers changed.

If the system is suspected of being short of refrigerant, a qualified service technician with EPA certification should be contacted to thoroughly check out the unit and add refrigerant if necessary.

Crankcase Heaters The compressors are equipped with crankcase heaters. The function of the heater is to keep the temperature in the crankcase high enough to prevent refrigerant from migrating to the crankcase and condensing in the oil during off-cycle. When a system is to be started up initially, the power to the heaters should be turned on for at least 12 hours before the compressors are started. The crankcase should be up to about 80°F (26.7°C) before the system is started up, to minimize lubrication problems or liquid slugging of compressor on start-up.

If the crankcase is cool (below 80°F) (26.7°C) and the oil level in the sight glass is full to top, allow more time for oil to warm before starting the compressor.

The crankcase heaters are on whenever power is supplied to the unit and the compressor is not running.

Optional Controls

Phase/Voltage Monitor (Optional) The phase/voltage monitor is a device that provides protection against three-phase electrical motor loss due to power failure conditions, phase loss, and phase reversal. Whenever any of these conditions occur, an input relay is deactivated, disconnecting power to the thermostatic control circuit. The compressor do a rapid shutdown pump down.

The input relay remains deactivated until power line conditions return to an acceptable level. Trip and reset delays have been provided to prevent nuisance tripping due to rapid power fluctuations.

When three-phase power has been applied, the input relay should close and the “run light” should come on. If the relay does not close, perform the following tests.

1. Check the voltages between L1-L2, L1-L3, and L2-L3. These voltages should be approximately equal and within +10% of the rated three-phase line-to-line voltage.

2. If these voltages are extremely low or widely unbalanced, check the power system to determine the cause of the problem.

3. If the voltages are good, turn off the power and inter-change any two of the supply power leads at the disconnect switch.

This may be necessary, as the phase/voltage monitor is sensitive to phase reversal. Turn on the power. The relay should now close after the appropriate delay.

Factory settings are as follows: Voltage Setting, set at nameplate voltage. Trip Delay Time, 2 seconds Restart Delay Time, 60 seconds


Hot Gas Bypass (Optional) This option allows passage of discharge gas to the evaporator, permitting operation at lower loads than available with compressor unloading. It also keeps the velocity of refrigerant gas high enough for proper oil return at light load conditions.

The pressure regulating valve is a Sporlan SHGBE-8 and factory set to begin opening at 69 psig and can be changed by changing the pressure setting. The adjustment range is 0 to 100 psig. To raise the pressure setting, remove the cap on the bulb and turn the adjustment screw clockwise. To lower the setting, turn the screw counterclockwise. Do not force the adjustment beyond the range it is designed for, as this will damage the adjustment assembly. The regulating valve opening point can be determined by slowly reducing the system load while observing the suction pressure. When the bypass valve starts to open, the refrigerant line on the evaporator side of the valve will begin to feel warm to the touch.

WARNING The hot gas line can become hot enough to cause personal injury in a very

short time; care should be taken during valve checkout.


Maintenance Schedule

I. Compressor A. Performance Evaluation (Log & Analysis) * O B. Motor • Meg. Windings X • Ampere Balance (within 10%) X • Terminal Check (tight connections, porcelain clean) X • Motor Cooling (check temperature) X C. Lubrication System • Oil Level O X • Oil Appearance (clear color, quantity) O

• Oil change if indicated by oil analysis X II. Controls A. Operating Controls • Check Settings and Operation X B. Protective Controls • Test Operation of: Alarm Relay X Pump Interlocks X High and Low Pressure Cutouts X III. Condenser B. Test Water Quality X C. Clean Condenser Tubes (or as required) X D. Eddycurrent Test - Tube Wall Thickness X E. Seasonal Protection X IV. Evaporator B. Test Water Quality X C. Clean Evaporator Tubes (or as required) X D. Eddycurrent Test - Tube Wall thickness (or as required) X E. Seasonal Protection X V. Expansion Valves A. Performance Evaluation (Superheat Control) X VI. Compressor - Chiller Unit A. Performance Evaluation O B. Leak Test: • Compressor Fittings and Terminal X • Piping Fittings X • Vessel Relief Valves X C. Vibration Isolation Test X D. General Appearance: • Paint X • Insulation X VII. Starter(s) A. Examine Contactors (hardware and operation) X B. Verify Overload Setting and Trip X C. Test Electrical Connections X VIII. Optional Controls A. Hot Gas Bypass (verify operation) X

Key: O = Performed by in-house personnel X = Performed by service personnel


System Service

DANGER

Service on this equipment is to be performed only by qualified refrigeration personnel. Causes for repeated tripping of equipment protection controls must be investigated and corrected. Disconnect all power before doing any service

inside the unit or serious personal injury or death can occur.

NOTE: Anyone servicing this equipment must comply with the requirements set forth by the EPA concerning refrigerant reclamation and venting.

Filter-Driers To change the filter-drier, pump the unit down (with the compressor running) by closing the manual liquid line shutoff valve(s). The unit will start pumping down until it reaches the low-pressure cutoff setting of 58 psi.

Close the discharge valve. Remove the refrigerant in the liquid line with a recovery unit to EPA required pressure. Remove and replace the filter-drier(s). Evacuate the lines through the liquid line manual shutoff valve(s) to remove noncondensables that may have entered during filter replacement. A leak check is recommend before returning the unit to operation.

Unit Arrangement Unit Size Type Filter-Drier Water-Cooled 030 - 060 Sealed/Brazed Water-Cooled 070 - 120 2-core Replaceable

Remote Condenser All 2-core Replaceable

Liquid Line Solenoid Valve The liquid line solenoid valve(s), which are responsible for automatic pumpdown during normal unit operation, do not normally require any maintenance. However, in the event of failure they can require replacement of the solenoid coil or of the entire valve assembly.

The solenoid coil can be removed from the valve body without opening the refrigerant piping by moving pumpdown switch(es) PS1 and PS2 to the “manual” position.

The coil can then be removed from the valve body by simply removing a nut or snap-ring located at the top of the coil. The coil can then be slipped off its mounting stud for replacement. Be sure to replace the coil on its mounting stud before returning pumpdown switch(es) PS1 and PS2 to the “auto pumpdown” position.

To replace the entire solenoid valve, follow the steps for changing a filter-drier.

Thermostatic Expansion Valve The expansion valve is responsible for allowing the proper amount of refrigerant to enter the evaporator regardless of cooling load. It does this by maintaining a constant superheat. (Superheat is the difference between refrigerant temperature as it leaves the evaporator and the saturation temperature corresponding to the evaporator pressure). All WGZ chillers are factory set for between 8°F and 12°F (4.4°C to 6.7°C) superheat at full load.


To increase the superheat setting of the valve, remove the cap at the bottom of the valve to expose the adjustment screw. Turn the screw clockwise (when viewed from the adjustment screw end) to increase the superheat and counterclockwise to reduce superheat. Allow time for system rebalance after each superheat adjustment.

The expansion valve, like the solenoid valve, should not normally require replacement, but if it does, the unit must be pumped down by following the steps involved when changing a filter-drier.

If the problem can be traced to the power element only, it can be unscrewed from the valve body without removing the valve, but only after pumping the unit down.

Figure 24, Thermostatic Expansion Valve

CAUTION

Adjustment of expansion valve should only be performed by a qualified service technician. Failure to do so can result in improper unit operation.

Note: Superheat will vary with compressor unloading, but should be approximately as follows: between 8°F and 12°F (4.4°C and 6.7°C) at full load; between 6°F and 10°F at part load.

Water-cooled Condenser The condenser is of the shell-and-tube type with water flowing through the tubes and refrigerant in the shell. External finned copper tubes are rolled into steel tube sheets and to the center dividing tube sheet. Integral subcoolers are incorporated on all units. All condensers are equipped with 450 psig (3104 kPa) relief valves. Normal tube cleaning procedures can be followed.

Evaporator The evaporator is a sealed, brazed-stainless steel plate unit. Normally no service work is required on the evaporator.


Troubleshooting Chart PROBLEM POSSIBLE CAUSES POSSIBLE CORRECTIVE STEPS

Compressor Will Not Run

1. Main switch, circuit breakers open. 2. Fuse blown. 3. Thermal overloads tripped or fuses

blown. 4. Defective contactor or coil. 5. System shut down by equipment

protection devices. 6. No cooling required. 7. Liquid line solenoid will not open. 8. Motor electrical trouble. 9. Loose wiring.

1. Close switch 2. Check electrical circuits and motor

winding for shorts or grounds. Investigate for possible overloading. Replace fuse or reset breakers after fault is corrected.

3. Overloads are auto reset. Check unit closely when unit comes back on line.

4. Repair or replace. 5. Determine type and cause of shutdown

and correct it before resetting protection switch.

6. None. Wait until unit calls for cooling. 7. Repair or replace coil. 8. Check motor for opens, short circuit, or

burnout. 9. Check all wire junctions. Tighten all

terminal screws.

Compressor Noisy or Vibrating

1. Flooding of refrigerant into crankcase. 2. Improper piping support on suction or

liquid line. 3. Worn compressor.

1. Check superheat setting of expansion valve.

2. Relocate, add or remove hangers. 3. Replace.

High Discharge Pressure

1. Condenser water insufficient or temperature too high.

2. Fouled condenser tubes (water-cooled condenser). Clogged spray nozzles (evaporative condenser). Dirty tube and fin surface (air cooled condenser).

3. Noncondensables in system. 4. System overcharge with refrigerant. 5. Discharge shutoff valve partially closed. 6. Condenser undersized (air-cooled). 7. High ambient conditions.

1. Readjust temperature control or water regulating valve. Investigate ways to increase water supply.

2. Clean.

3. EPA purge the noncondensables. 4. Remove excess refrigerant. 5. Open valve. 6. Check condenser rating tables against

the operation. 7. Check condenser rating tables against

the operation.

Low Discharge Pressure

1. Faulty condenser temp. regulation. 2. Insufficient refrigerant in system. 3. Low suction pressure. 4. Condenser too large. 5. Low ambient conditions.

1. Check condenser control operation. 2. Check for leaks. Repair and add charge. 3. See corrective steps for low suction

pressure below. 4. Check condenser rating table against the

operation. 5. Check condenser rating tables against

the operation.

High Suction Pressure

1. Excessive load. 2. Expansion valve overfeeding.

1. Reduce load or add additional equipment.

2. Check remote bulb. Regulate superheat.

Low Suction Pressure

1. Lack of refrigerant. 2. Evaporator dirty. 3. Clogged liquid line filter-drier. 4. Clogged suction line or compressor

suction gas strainers. 5. Expansion valve malfunctioning. 6. Condensing temperature too low. 7. Compressor will not unload. 8. Insufficient water flow.

1. Check for leaks. Repair and add charge. 2. Clean chemically. 3. Replace cartridge(s). 4. Clean strainers. 5. Check and reset for proper superheat.

Replace if necessary. 6. Check means for regulating condensing

temperature. 7. See corrective steps for failure of

compressor to unload. 8. Adjust flow.

Little or No Oil Pressure

1. Clogged suction oil strainer. 2. Excessive liquid in crankcase. 3. Low oil level. 4. Flooding of refrigerant into crankcase.

1. Clean. 2. Check crankcase heater. Reset

expansion valve for higher superheat. Check liquid line solenoid valve operation.

3. Add oil. 4. Adjust thermal expansion valve.


PROBLEM POSSIBLE CAUSES POSSIBLE CORRECTIVE STEPS

Compressor Loses Oil

1. Lack of refrigerant. 2. Velocity in risers too low (A-C only). 3. Oil trapped in line.

1. Check for leaks and repair. Add refrigerant.

2. Check riser sizes. 3. Check pitch of lines and refrigerant

velocities.

Motor Overload Relays or Circuit Breakers Open

1. Low voltage during high load conditions. 2. Defective or grounded wiring in motor or

power circuits. 3. Loose power wiring. 4. High condensing temperature. 5. Power line fault causing unbalanced

voltage. 6. High ambient temperature around the

overload relay

1. Check supply voltage for excessive line drop.

2. Replace compressor-motor. 3. Check all connections and tighten. 4. See corrective steps for high discharge

pressure. 5. Check Supply voltage. Notify power

company. Do not start until fault is corrected.

6. Provide ventilation to reduce heat.

Compressor Thermal Switch Open

1. Operating beyond design conditions. 2. Discharge valve partially shut.

1. Add facilities so that conditions are within allowable limits.

2. Open valve.

Freeze Protection Opens

1. Thermostat set too low. 2. Low water flow. 3. Low suction pressure.

1. Reset to 42°F (6°C) or above. 2. Adjust flow. 3. See “Low Suction Pressure.”

Warranty Statement

Limited Warranty Consult your local McQuay Representative for warranty details. Refer to Form 933-43285Y. To find your local McQuay Representative, go to www.mcquay.com.

Post Office 2510, Staunton, Virginia 24402 USA • (800) 432-1342 • www.mcquay.com IMM WGZ-2 (10/05)

This document contains the most current product information as of this printing. For the most up-to-date product information, please go to www.mcquay.com.

Water-Cooled Scroll Compressor Chillers

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