McQuay

Your Climate... We’ re ThereYour Climate... We’ re There

McQuay International 210.06.03/

THE NEW FRAME 4 COMPRESSORTHE NEW FRAME 4 COMPRESSOR

service & applicationservice & application


Overview

McQuay have carried out an extensive analysis of thepossible green alternatives refrigerants R410A, R407C,R404A, R134a

This has shown that whilst R407C should be retainedfor piston and scroll compressors and R134a for screwunits

McQuay has designed a screw compressor -- the Frame4 which is optimized for R134a


Design Philosophy

R134a is a lower pressure, higher volume refrigerant than R22 and even more so when compared with R410a - so the swept volume must be increased at minimal cost.

The simplest way to achieve this is to use a larger diameter rotor and gates.

Oil injection has been used to COP at high condensing pressures.


Design Philosophy--contd.

R134a almost always benefits from the use of an economizer but toto simplify the compressor design this will be external to the compressor.

As the economizer will be external, the motor has also been simplifiedand is gas cooled rather than refrigerant cooled like the Frame 2.

In line with normal J & E Hall practice the compressor has infinitelyvariable capacity control down to 25%. This provides an additional selling feature against competitors with step control.

From day one it will be available with an electronic soft-start.


Screw chiller frame 4 compressorScrew chiller frame 4 compressor


Rotor & Bearing Design

Three bearings for reliability and low vibration

Simple gas-cooled motor


Rotor Access

Large aperture for easy access


Star-gate Assembly

Simple bearing cap assembly gives good location and easy removal


Star-gate


Capacity Slide Assembly

Spring-loaded slide for auto-return

Porting designed for R134A

Symmetrical unloading for balanced bearing loads


Capacity Slide


Main Feature Benefits

High efficiency -- COP >3.2 @ ARI air-cooled

Reliability -- oil injected, large clearances, 3 bearings

Low vibration --- < 0.07mm/s ( 50% of FR2)

Infinitely variable capacity control -- With optional feedback.

Ease of maintenance

Competitive price -- Lower cost/ton than FR2

Lower in-rush current -- Star/Delta or soft-start


ALS Fr4ALS Fr4


ALS Fr4ALS Fr4

546

1 32

Suction side


ALS Fr4ALS Fr4


PFS Fr4PFS Fr4


PFS Fr4 - R134a water pressure control system Prestart: The Pico controller verify the condenser entering water temperature and the evaporator livingwater temperature.Thus values will be automatically converted by it self by the internal pressure/temperaturetable.§ If the ratio of thus calculated pressure is bigger than 1.6 the controller will start thecompressors following the standard starting procedure.§ If the ratio is lower than 1.6 the controller will start the compressors following the"cold start" starting procedure.

PFS Fr4PFS Fr4


PFS Fr4PFS Fr4

"Cold start" starting: The Pico controller, when the compressor start, send a signal to the electronic expansion valve (2valves working together for "Dual" units) for 20% of full opening status. During this situation, themain Driver function is disabled, so the Pico controller it self, instead to follow the target suctionsuperheat, will check the refrigerant pressure ratio (absolute condensing pressure/absoluteevaporating pressure) opening or closing the "EXV" and trying to maintain it between 2.1 and 2.3. Ifthis ratio go below 2.1, the controller sends to the valve a signal for close. If the ratio go above 2.3,the signal that the controller send to the valve is for opening. With a ratio value between thementioned numbers the controller will send no signals to the EXV (dead band) so that it will sayfixed.During the WPC status, suction super heat and liquid sub cooling reach very high values but, in thiscase, these must be ignored.As the evaporator and condenser water goes closer to the project conditions, the suction super heatvalue decrease continuously. The "cold start" starting is closed when the suction super heat valuereach 2°K. At this point the controller gives back to the Driver the EXV control, and it will drive thevalve to achieve a suction super heat around 0.5°K.During the "cold start" starting is possible that append the following anomalous conditions:


PFS Fr4PFS Fr41. Low suction pressure: If the electronic expansion valve closes to much, in order to

guarantee the minimum pressure ratio, is possible that the suction pressure goes below the freezingvalue. In this case the controller will unload the compressor/compressors up to the pressure value reachat list 0°C (calculated). If this situation should not happen, after 120 sec. The controller will switch offone compressor under low pressure alarm . If also after this operation the pressure will remain below0°C (calculated), after additional 120 sec. The controller will switch off the second compressor (Ifexisting). The time delay is less than 40 sec. When the calculated saturated evap. Pressure is lower equalthan -10°C.

2. High delivery pressure: the excessive liquid refrigerant storage in the condenser shell, due tothe cold start starting mode, could excessively reduce the heat transfer surface of the heat exchanger. Inthis condition the condensing pressure could increase above the maximum allowable value. At this pointthe Pico controller will unload the compressors following the standard "stage hold - stage down" logic.

3. High delivery super heat: the increasing suction super heat, due to the suction pressure

reduction already described, will provoke a rise of the delivery super heat. If during the WPC thedelivery temperature should achieve the maximum allowable value (setted to 85°C as default), the Picocontroller will go ahead with the standard "liquid injection oil cooling" procedure, energising the liquidinjection solenoid coil by an output signal from the "OD06" digital output. If the temperature should riseagain, the Pico controller will stop the compressor when the temperature will achieve 95°C under alarm.If the temperature start to go down, The Pico controller will stop the "liquid injection oil cooling"procedure when the temperature will achieve the mentioned set point less the differential value (10°C).


During "Running" condition: Is possible that, in running condition, the condenser entering water temperature excessively reduce dueto (for instance) an anomalous control of the cooling tower.In this case the pressure ratio could go down below the minimum set point (2.0).The Pico controller will react with the WPC logic as above described.

PFS Fr4PFS Fr4


PFS Fr4PFS Fr4


PFS Fr4 – Vintage APFS Fr4 – Vintage A

StandBy Compressor By HP Prevent 11.0 bar

Tranducer HP Warning 11.5 bar

Tranducer HP alarm 12.0 bar

Tranducer LP alarm 2.5 bar


PFS Fr4 – Vintage BPFS Fr4 – Vintage B






PFS Fr4 – Vintage CPFS Fr4 – Vintage C





Cooling Tower Control (as per ALS fan control)

3 way valve control

WP start control

New I/O: all probes enabled on both master andslave pCO card


WHS Fr4WHS Fr4


Frame Frame 4 4 Opening to Opening to the Worldthe World

Frame 4 Screw chillers are managed byCAREL pCOTM controllerspCOTM boards are connected innetwork using the pLANTM link



You can skip between different boards simply bypressing on status & info keysSettings have to be inserted / verified for eachboard.Settings are divided in three classes, underdifferent passwords: USER, MANUFACTURER andCAREL



User parameters PSW 003Summer temperature setpoint limits:

Low 05.0 °CHigh 17.0 °C

Regulation temperature:Type OUTLET

Outlet regulation force offSummer 3.0 °CWinter 45.0 °C

Temperature Band 03.0 °CModulation Band

Neutral zone 02.0 °CTime between main pump/fan and Compressor start 030sDelay on switching the main Pump off 180s Digital input remote On / Off YesDigital input remote Summer / Winter NoSupervisory remote On / Off NoSupervisory remote Winter / Summer NoInsert another user psw 0003

Set parametersSummer setpoint 07.0 °CWinter setpoint 45.0 °C



Manufacturer parameters PSW 033Unit config. water/air chiller 00Probes enable: B1, B2, B4, B7, B8 (MSTR)Probes enable: -, -, B4, B7, B8 (SLAVE)High pressure probe config.

4mA 0.0 bar20mA 30.0 bar

Low pressure probe config.4mA 0.0 bar20mA 30.0 bar

Enable double setpoint: NoCompressor config.:

Enable driver YesN. of compressor 2Rotation comp. Yes

Type of unloads: ModulantTime Star/line 0,15sTime Star 4,0sTime Star/Delta. 0.05s

Enable start restriction No

Time to reach min. power 120sMinimum compr. power-off time 120sTime to reach max power 100sMin time betw. Same comp. Strts 600sEnable particular manag. of stg1 NoTime Sol./S1 3sStandby config. Compressor

Relay 6 OFFRelay 7 OFF

Decrement config. CompressorRelay 6 OFFRelay 7 ON

Increment config. CompressorRelay 6 ONRelay 7 OFF

Modulation Config.Pulse period 2smin. pulse D 0.5smax pulse D 0.5smin. pulse I 0.5smax pulse I 0.5s



Manufacturer parameters PSW 033Time force decr. For start cmprssr 08sForce solenoid with compr. OFF NoPump down config.

Enable YesMaximum time 15s

En pressure prevent YesSby compr. by HP Prevent 13.0 barTransducer high pressure warning

setpoint 14 bardiff. 2,0 bar

Discharge temp. Prevent YesSetpoint 110°CDiff. 10°C

Freeze prevent 5.0°Cdiff. 1.0°C

CondensationEnable Pressure

TypeINVERTER STEPFan number 1Condensation

Setpoint 6.0 barDiff. 4.0 bar

Inverter config.Max speed 10.0 VMin. speed 04.0 VSpeed up time 01s

Step 1Setpoint XX.0 bar

Diff. X.0 bar Inverter config.

Point C 7.0 barPoint D 8.0 barPoint F 10 VPoint B 10.0 barPoint E 10.0 bar

Step 2Setpoint XX.0 bar

Diff. X.0 bar


Frame Frame 4 4 Opening to Opening to the Worldthe WorldManufacturer parameters PSW 033

Enable serious alarm YesValve open when compr. switces on

40%Driver Alarm Switch off driver 1 comp whenbattery error NoDriver Alarm Switch off driver1 compif LOP mode N

Delay 00.0 minEvaporator flow alarm Yes(MASTER)Evaporator flow alarm No (SLAVE)Enable condenser flow alarm NoEnable phase alarm Yes(MASTER)Enable phase alarm No (SLAVE)Evaporator flow alarms delays NoStart-up delays 20sRun delay 05sTransducers high pressure alarm

Setpoint 17.0 bar

Diff. 03.0 bar Transducers low pressure alarmSetpoint 01.0 barDiff. 00.5 barLow diff. Press. Alarm

Setpoint 04.0 barStart-up delay 120sRunning delay 060s

Low pressure alarm delaysStart-up delay 050sRun delay 20s

Oil differential alarm delaysStart-up delay 180sRun delay 090s

Oil level alarm delaysStart-up delay 120sRun delay 010s



Manufacturer parameters PSW 033Antifreeze alarm

Setpoint 03.0 °CDiff. 01.0 °C

Electrovalve management Setpoint85°C

Diff. 10°CAntifreeze heater

Setpoint 04.5 °CDiff. 01.0 °C

Clock board 32K EnableYSupervisor System CommunicationSpeed 1200 (RS485/RS422)Identification No.:nn

Circuit 1 config. EXV manufacturerInsert password 0000

Circuit 1 EXV Carel parametersInsert password 0000

Reset all parameters to default valueNo

Insert another manufacturer psw0033



pCo I/O Layout

McQuay

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