Annexure -1 TECHNICAL SPECIFICATIONS

A Water cooled centrifugal type water chilling units

a. Scope i. The scope of this section comprises the supply, erection, testing and

commissioning of the AHRI Certified Water Chilling Units conforming to these specifications and in accordance with the requirements of the Schedule of Equipment

b. Codes & standards i. The Water-cooled liquid chilling packages shall conform to the latest

edition of following: ASHARE 15 Safety codes for Mechanical refrigeration

ASHARE 23

Methods of testing and rating positive displacement

refrigerant compressors and Condensing Units

ASHARE 30 Methods of testing liquid Chilling packages

ASMEC SEC VIII DIV 1 Boiler and pressure vessel code

ANSI B 31.5 Code for refrigerant piping

ARI 550/590 (1998) Standard for Centrifugal and Rotary Water Chilling

packages

ARI 575 Standard for method of measuring machinery sound within

an equipment space

ISO 1940 Mechanical vibration – Balance quality requirements of

rigid rotors

ISO 10816-1

Mechanical vibration – Evaluation of machine vibration

of measurements on non-rotating parts. General

Guidelines.

c. Compressor

i. The Compressor will be a single-stage/multistage centrifugal type powered by a totally enclosed electric motor. The housing will be fully accessible with vertical circular joints, with the complete operating assembly removable from the compressor and scroll housing. Compressor castings will be designed for desired working pressure and hydrostatically pressure tested for R-134a units. The rotor assembly will consist of a heat-treated alloy steel drive shaft and impeller shaft with a cast aluminum, fully shrouded impeller. The impeller will be designed for balanced thrust, dynamically balanced and over speed tested for smooth, vibration free operation. Insert-type journal and thrust bearings will be fabricated of aluminum alloy, precision bored and axially grooved.

ii. Internal single helical gears with crowned teeth will be designed so that more than one tooth is in contact at all times to provide even load distribution and quiet operation. Each gear will be individually mounted in its own journal and thrust bearings to isolate it from

impeller and motor forces. A forced fed/gravity-fed oil reservoir will be built into the top of the compressor to provide lubrication during close down in the event of a power failure.

iii. Capacity control will be achieved by use of pre-rotation vanes to provide fully modulating control from maximum to minimum load. The unit will be capable of operating with lower temperature cooling tower water during part-load operation in accordance with ARI Standard 550/590. Pre-rotation vane position will be automatically controlled by an external electric actuator to maintain constant leaving chilled water temperature.

iv. The Compressor shall be equipped with either moveable discharge, spiraling or variable geometry diffuser to ensure stable operation at low loads

v. The Chiller shall be able to unload up to 25% capacity at constant condenser entering water temperature (90°F).

d. Lubrication system i. Lubrication oil shall be force-fed to all compressor bearings, gears and

rotating surfaces by an external variable speed oil pump. The oil pump shall vary oil flow to the compressor based on operating and stand-by conditions, ensuring adequate lubrication at all times. The oil pump shall operate prior to start-up, during compressor operation and during close down. Compressor shall have an auxiliary forced fed reservoir to provide lubrication during close down in the event of power failure. The oil reservoir shall be designed in accordance with ASME or applicable pressure vessel code.

ii. Oil shall be filtered to allow the filter change without removal of refrigerant charge. An automatic oil return system to recover any oil that may be migrated to evaporator shall be provided. Oil piping shall be completely factory installed & tested.

e. Motor drive line i. The compressor motor will be IP-54 high efficiency continuous duty

totally enclosed (TERC/TEFC) squirrel cage induction type suitable for 415Volts, 3-Phase, 50Hz AC Supply. Motor shall be designed for 3000RPM Synchronous speed.

ii. Full load rating of the motor shall be at least 15% higher than Compressor KW requirement at fault load. On motor winding temperature sensor shall be provided.

iii. Motor drive shaft will be directly connected to the compressor shaft with a flexible disc coupling. Coupling will have all metal construction with no wearing parts to assure long life, and no lubrication requirements to provide low maintenance.

f. Variable frequency drive i. A variable speed drive should be minimum IP42 or as per standard of

chiller manufacturer & have capacity control logic inbuilt into the system. VSD will vary the compressor motor speed by controlling the frequency & voltage of the electrical power to the motor. The adaptive capacity control logic shall automatically adjust motor speed

and compressor pre-rotation vane position independently for maximum part load efficiency by analyzing information fed to it by sensors located throughout the Chiller.

ii. The following Features will be provided: 1. Door interlocked circuit breaker capable of being padlocked. 2. UL listed ground fault protection. 3. Over voltage and under voltage protection. 4. 3-Phase sensing motor over current protection. 5. Single phase protection. 6. Insensitive to phase rotation. 7. Over temperature protection. 8. THD/TDD to 5% at equipment level 9. Make of VFD shall be exactly same as global catalogue. No

local arrangement shall be applicable. 10. All the cabling, piping, junction boxes/trolley or stands shall be

inclusive of the rates quoted g. Evaporator

i. Evaporator will be of the shell and tube flooded type even pass designed for 150 psig working pressure on the refrigerant side. Shell will be fabricated from rolled carbon steel plate with fusion welded seams; it shall have carbon steel tube sheets, drilled and reamed to accommodate the tubes. The refrigerant side will be designed and tested in accordance with ASME & U Stamped code. Tubes shall be of high efficiency, internally and externally enhanced type having plain copper ends at all intermediate tube supports to provide maximum tube wall thickness at the support area. Each tube will be roller expanded into the tube sheets providing a leak-proof seal, and be individually replaceable. Water velocity through the tubes will not exceed 10 fps. Water pressure drop shall be less than 20ft of water. Evaporator shall be designed to prevent liquid refrigerant entering to compressor. Devices that introduce pressure losses (such as mist eliminators) shall not be acceptable because they are subject to structural failures that can result in extensive compressor damage. The evaporator will have a refrigerant relief device sized to meet the requirements of ASHARE-15 Safety Code for Mechanical Refrigeration.

ii. The Chiller shall be provided with following connections and accessories as separately identified in the Schedule of Quantities.

1. Water Inlet and Outlet connections with suitable size butterfly valves.

2. Drain and vent connections with stop valves. 3. Dial type pressure gauges and stem type thermometers on

Inlet and Outlet connections. 4. Water flow switches at the Outlet. 5. De-scaling valves. 6. Ribbed rubber isolator or pads to eliminate transmission of

vibration up to 90%.

iii. Chiller shall be factory insulated with 25mm thick polyvinyl nitrile rubber insulation on cooler shell and suction elbow. The insulation

material shall have thermal conductivity not exceeding 0.0404 W/mC

(0.28 Btu/Hr SQft.F per inch). Hydraulic pressure of 10 Kg/SQ.Cm. shall be applied on the water side and shall be maintained for a period of 24 hours without any drop in pressure to ensure that there is no leakage.

h. Refrigeration flow control i. Refrigerant flow to the Evaporator will be controlled by a variable

orifice or Thermostatic expansion valve for improving unloading capabilities.

i. Ahri certification i. The Chilling Unit shall be AHRI Certified as per ARI 550/590 – 2003

STANDARD. All bidders shall furnish computer printouts showing part load data as per ARI Standards along with their technical bids.

j. Microprocessor control center i. The Chiller shall be controlled by a stand-alone microprocessor based

Control Centre. The Chiller Control Panel shall provide Control of Chiller operation and monitoring of Chiller Sensors, Actuators, Relays and Switches. The Chiller shall be provided with a factory installed and wired microprocessor control center. The Control Centre shall include a suitable liquid crystal display, function keys, stop button and alarm light. The microprocessor can be configured for FPS Units or SI Units.

ii. The Chiller Control System shall have the ability to interface and communicate directly to the building control system. All VFD parameters must be displayed on chiller panel.

iii. The default standard display screen shall simultaneously indicate the following minimum information:

1. Date and time of day. 2. 24-character primary system status message. 3. 24-character secondary status message. 4. Chiller operating hours. 5. Entering Chilled water temperature. 6. Leaving Chilled water temperature. 7. Evaporator refrigerant temperature. 8. Entering Condenser water temperature. 9. Leaving Condenser water temperature. 10. Condenser refrigerant temperature. 11. Oil supply pressure. 12. Oil sump temperature. 13. Percent motor Rated Load Amps (RLA)

iv. The 4 function keys shall be software driven within the Status, Schedule, Set Point and service menu structures.

v. Status Function: 1. In addition to the default screen, status screens shall be

accessible to view the status of every point monitored by the control center including evaporator pressure.

2. Condenser pressure. 3. Bearing oil supply temperature. 4. Compressor discharge temperature. 5. Motor winding temperature. 6. Number of compressor starts. 7. Control point settings. 8. Discrete output status of various devices. 9. Compressor motor starter status. 10. Optional spare input channels

vi. Set Point: 1. The Controls shall provide the capability to view and change

the leaving chilled water set point, entering chilled water set point and demand limit set point at any time during chiller operating or shut down periods. The Controls shall allow for the specifications of capacity control by either leaving chilled water or entering chilled water.

vii. Service Function: 1. The Controls shall provide a password protected service

function which allows authorized individuals to: View an alarm history file which shall contain the last 25 alarm/alert messages with the time and date stamp. These messages shall be displayed in text form and not in codes.

2. Execute a chiller controls test function for quick identification of malfunctioning components.

3. View/modify chiller configuration. 4. View/modify chiller occupancy periods. 5. View/modify holiday periods. 6. View/modify schedule override periods. 7. View/Modify system time and date.

viii. Network Window Function 1. Each Chiller shall be capable of viewing multiple point values

and statuses from other like controls connected on a common network, including controller maintenance data. The operator shall be able to alter the remote controller’s set point or time schedule and force point values or statuses for those points that are operator forcible. The operator shall also have access to the alarm history file of all like controllers connected on the network.

2. The Control Centre shall allow reset of the chilled water temperature set point based on any of the following criteria:

a. Chilled water rest based on an external 4 to 20 mA signal.

b. Chilled water reset based on a remote temperature sensor (such as outdoor air).

c. Chilled water reset based on water temperature rise across the evaporator.

ix. Safeties:

1. Unit shall automatically shut down when any of the following conditions occur: (Each of these protective limits shall require manual reset and cause an alarm message to be displayed on the screen, informing the operator of the shut down cause)

a. Motor over current. b. Over voltage*. c. Under voltage*. d. Single cycle dropout*. e. Bearing oil high temperature. f. Low evaporator refrigerant temperature. g. High condenser pressure. h. High motor temperature. i. High compressor discharge temperature. j. Low oil pressure. k. Prolonged surge. l. Loss of cooler water flow. m. Loss of condenser water flow. n. Starter fault.

2. * Shall not require manual reset or cause alarm if auto-restart after power failure is enabled.

3. The control System shall detect conditions that approach protective limits and take self- corrective action prior to an alarm occurring. The system shall automatically reduce chiller capacity when any of the following parameters are outside their normal operating range:

a. High condenser pressure. b. High motor temperature. c. Low evaporator refrigerant temperature. d. High motor amps.

x. Diagnostics and Service 1. The Control System shall execute a series of pre-start checks

whenever a start command is received to determine if pressures, temperatures and timers are within pre-start limits, thereby allowing start-up to proceed. If any of the limits are exceeded, a text alert message shall be displayed informing the operator of the cause of the pre-start alert.

2. A self diagnostic controls test shall be an integral part of the control system to allow quick identification of malfunctioning components.

k. Vibration isolation i. The Unit shall have four vibration isolation mounts consisting of 1”

thick neoprene isolation pads for field mounting. The pads shall be mounted under the steel mounting pads on the tube sheets suitable for ground floor installation.

l. Installation

i. The Chilling Machine shall be installed over a cement concrete platform and shall be adequately isolated as per manufacturer recommendations against transmission of vibrations to the building.

m. Testing i. There shall be witness of performance tests of the Chiller for COP at

100% Load at ARI Certified test bed in factory. The same VFD shall also be tested for performance and TDD/THD

n. Start up i. The Chiller manufacturer shall provide a factory trained

representative employed by the Chiller manufacturer to perform the start-up procedures as outlined in the start-up, operation and maintenance manual provided by the Chiller manufacturer.

ii. After the above services have been performed the same factory trained representative shall be available for classroom instruction not to exceed a period of 4 hours to instruct the owner’s personnel the proper operation and maintenance of the Chiller.

iii. Manufacturer shall supply the following literature: 1. Star-up, operation and maintenance instructions & manual. 2. Installation instruction. 3. Field wiring diagrams.

o. Painting i. All equipment and bases shall be painted as per standard.

B Pumps

Split Coupled Vertical Inline Primary, Condenser & Secondary Water Pumps a. Supply and install of Split Coupled (long coupled) Type Vertical In-Line

Centrifugal pumping unit. The pumps shall be radially split, single stage centrifugal type with CI/GM casing with equal size suction and discharge flanges and having separate tapped flush line and pressure gauge connections, Gunmetal Bronze (BS1400 LG2C) dynamically balanced impeller, stainless steel shaft, lower carbon throttle bushing, Outside Balanced type mechanical seal with Resin Bonded Carbon rotating face, Sintered Silicon Carbide stationary seat and Viton secondary seal.

b. The pump is to be fitted with a factory installed flush line. Supply in the flush line to the mechanical seal, a 50-micron cartridge filter (alternatively, a cyclone separator when pump differential pressure exceeds 30 PSIG) and floating ball type sight flow indicator suitable for the working pressure encountered. The mechanical contractor shall change the filters after the system has been flushed and on a regular basis until the pumps are turned over to the owner. The squirrel cage induction type motor, with TEFC enclosure and shall be connected to the pump through a high tensile aluminum, split type spacer coupling to permit Servicing of the mechanical seal without disturbing pump, motor or electrical wiring. Coupling shall be protected by a guard.

Split Coupled Vertical Inline Primary variable water Pumps

c. The Vertical In-Line (VIL) pump single stage, single or double suction type, with pump characteristics which provide rising heads to shut off, shall be supplied with a TEFC, 415/3/50 motor efficiency equivalent to IE2 and an IP55/UL Type 12 enclosure variable speed VFD.

d. The drive shall be integrated with the motor for a self-contained pump, motor and drive combination to ensure optimum component matching and protection from motor overloading at any operating point within the design or operating range.

e. Pump Construction i. Pump Casing - Cast Iron with PN16 flanges for working pressure to 12

bar at 65°C and Ductile Iron with PN25 flanges for working pressures to 25 bar at 65°C. Suction and discharge connections shall be flanged and the same size and shall be drilled and tapped for seal flush and gauge connections.

ii. Impeller - Bronze, fully enclosed type. Dynamically balanced. Two-plane balancing is required where installed impeller diameter is less than 6 times the impeller width.

iii. Shaft - Provide Stainless Steel pump shaft. iv. Coupling - Rigid spacer type of high tensile aluminum alloy. Coupling

to be designed to be easily removed on site to reveal a space between the pump and motor shafts sufficient to remove all mechanical seal components for servicing and replacement without disturbing other components of the pump or motor. The coupling shall be provided with a fully enclosed guard complying with the Machinery Directive.

v. Mechanical Seals - Shall be Stainless Steel multi-spring outside balanced type with Viton® secondary seal, carbon rotating face and silicon carbide stationary seat. Provide a 316 stainless steel gland plate. Provide factory installed flush line with manual vent to purge air prior to pump start-up. All split coupled pumps shall be provided with a lower seal chamber throttle bushing to ensure seals maintain positively cooling and lubrication. Seal flush line accessories, if required to improve seal chamber cleanliness: Supply in the flush line to the mechanical seal a 50-micron cartridge filter and sight flow indicator, to suit the working pressure encountered. Filters shall be changed, by the installing contractor, after system is flushed and on a regular basis until turned over to the owner.

Integrated Variable Frequency Drive (VFD)

f. Fundamental Requirements i. VFD shall be of the VVC-PWM type providing near unity displacement

power factor (cos Ø) without the need for external power factor correction capacitors at all loads and speeds.

ii. VFD shall incorporate DC link chokes for the reduction of mains borne harmonic currents to reduce the DC link ripple current thereby increasing the DC link capacitors lifetime. VFD shall be CE Marked showing compliance with both the EMC Directive 2004/108/EC and the Low Voltage Directive 2006/95/EC.

iii. RFI filters shall be incorporated within the drive to ensure it meets the emission and immunity requirements of EN61800-3 to the 1st Environment Class C1 (EN55011 unrestricted sales class B).

g. VFD and Motor Protection

i. VFD and motor protection shall include: motor phase to phase fault, motor phase to ground fault, loss of supply phase, over voltage, under voltage, motor over temperature, inverter overload, over current. Over current is not allowed ensuring Intelligent variable speed.

ii. Units will not overload the motor at any point in the operating range of the unit.

h. User Interface i. VFD shall incorporate an integrated graphical user interface that shall

provide running and diagnostic information and identify faults and status in clear English language. Faults shall be logged / recorded for interrogation at a later date.

ii. It shall be possible to upload parameters from one VFD into the non-volatile memory of a computer and download the parameters into other drives requiring the same settings.

iii. The keypad shall incorporate Hand-Off-Auto pushbuttons to enable switching between remote and manual control.

i. Control Algorithm i. Control software (Sensor/ Sensor-less) shall be embedded in the

Integrated Variable control unit to provide automatic speed control in variable volume systems with/ without the need for differential pressure sensor. The default operating mode under sensor/ Sensor-less Control shall be 'quadratic pressure control' whereby head reduction with reducing flow will be according to a quadratic control curve. Control mode setting and minimum / maximum head set-points shall be user adjustable via the inbuilt programming interface.

ii. If the quantity of pumps in a system is 2 to 4-maximum, including any standby, a controller shall be added to a pumping unit and set up at the factory to operate in parallel mode. The pump controls, which will be linked on site by the control contractor, will automatically stage the units, as appropriate, to maintain the best efficiency pumping and minimum operating cost. The standby unit will be brought into the rotation to exercise and equalize wear. The sequence of controls and staging points will be submitted to the engineer for approval at the time of order.

iii. Serial Communications: The VFD shall incorporate a USB port for direct connection to a PC and / or an RS485 connection with Modbus RTU protocol.

iv. Optional protocols available should include Lonworks and BACnet j. Other Control Features

i. The VFD shall have the following additional features: 1. Override for BMS 2. Manual pump control or closed loop PID control 3. Programmable skip frequencies and adjustable switching

frequency for noise / vibration control 4. Auto alarm reset 5. Motor pre-heat function 6. Minimum three programmable digital inputs

7. Minimum one analogue inputs 8. One programmable analogue / digital output Two volt-free

contacts 9. System Control – Sensor/Sensor less Control and Multiple

Pumps with Pump logic control. Duty Pump & Standby pumps with Sensor/ Sensor less Control

k. Controller shall allow the design parameters to be loaded into each integrated drive, including pump flow, pump head and minimum pressure setting. The minimum pressure setting is a value similar to a remote system sensor setting, if it were to be used. The control shall then set the pump control curve to control the pump in an identical manner as control with a remote sensor feedback. For Sensor less/ Sensor shall Control the remote system sensor is not required. The design parameters are to be entered into the integrated drive by means of the built-in graphical user interface.

l. Duty Pump & Standby pumps with Remote Sensor or building system (BMS) control

i. The remote differential pressure or flow sensor set-point value shall be loaded into each integrated drive. The drive shall then control the motor speed to satisfy the remote sensor setting. For BMS control the BMS is to provide the signal to the duty integrated drive to control the speed of the motor. Sensor less Control is not required for either of these options and can be de-activated by means of the user interface or by making terminal connections.

m. Multiple Pump System Control i. Supply a controller to control the pumps to satisfy all system sensor

settings at the minimum speed possible and at maximum efficiency under any flow conditions. Pump curves showing the staging points to maintain maximum efficiency shall be supplied with the submittal data.

Performance and Operating Logic n. The pump logic controller shall determine the most efficient combination of

operating pumps, and pump operating speed based on feedback from the DP sensors at the remote loads. The pump logic controller shall respond to the most dissatisfied zone by increasing either, the number of operating pumps, or the pump speed. In the case where all zones are satisfied the pump logic controller shall respond by decreasing either, the number of operating pumps, or the pump speed so as to optimize the energy efficiency of the pumping operation while meeting system demand. The pump logic controller shall continuously monitor all zone signals to determine an active control zone. Use of a multiplexer for multiple sensor inputs is not acceptable. To prevent unnecessary changes to the operating pump speed, to become the active control zone, the candidate zone must have a greater error from set-point than the current active control zone for greater than 5 minutes. This transition delay period, 5 minutes, shall be a field adjustable parameter that can be altered by the password protected users.

o. The pump logic controller shall sequence the pumps based on a field adjustable interval of operating hours with a "bump less" transfer algorithm. The logic controller shall incorporate embedded logic to prevent hunting, pump flow surge, and motor overloading. The logic shall incorporate an adjustable PID control loop. PID control at the VFD is not acceptable.

p. Should one VFD/ pump unit fail, the appropriate alarm signal shall be activated.

q. The controller shall have hand-off-automatic (H-O-A) control and should provide the option for a remote on/off signal from a single dry type relay, or BMS communication signal.

r. The pump logic controller shall provide a data-logging feature including alarms, and events (adjustment to system parameters). The pump logic controller shall offer the option for expanded memory of 4 megabytes for a rolling record of system parameters at 10 second intervals, with a time stamp.

s. The pump logic controller shall be self-prompting. All messages shall be displayed in plain English. The operator interface shall have; Multi-fault memory and recall, On-screen help functions, and separate user screens for:

i. Zone setups (including calibration of DP/T/Flow sensor range) ii. Pump configuration

iii. Design set-point and end of curve data iv. Alarm history and event review v. Display of zone status, pump status and system status

vi. Factory default / commissioning setup data t. The controller shall be capable of serial communications with Modbus, Lon

Works, Trend, and Metasys protocols. The controller shall offer the option of gateways for both BACnet and TCP/IP protocol connection for communication over the internet.

u. The pump logic controller shall automatically disable any zone DP signals that are not within limits and alert the operator of a possible transmitter failure. Should system failure be detected the pump speed will default to a pre-defined percent of full speed (factory default loaded as 90% of full speed). The pump logic controller shall have a minimum speed limit entered as a field adjustable parameter, factory loaded default set to 30% of full speed.

Parallel Pump Controller. v. For Intelligent Variable Speed pumping units, Pumps operating in parallel, the

pump logic controller shall be Parallel Pump Controller. The pump logic controller shall be specifically designed for the control of multiple pumps in HVAC hot and/or chilled water systems that involve up to 4-variable speed pumps, with Control, in parallel, staged, sequenced, and standby configurations. The pump logic controller shall allow field adjustments of control parameters as described below.

w. The controller shall be capable of accepting, processing and displaying appropriate signals from the individual pump controls for the following values:

i. System Status

1. Total flow 2. Head 3. Total power 4. Pumps speed 5. Alarm 6. Wire to water efficiency (calculated) 7. Number of pumps running 8. Lead pump number

ii. Individual Pump Status 1. Speed Ref (%) 2. Speed (%) (rpm) 3. Run time (hrs) 4. Fault Nbr 5. Run status (running/stopped)

iii. Individual Pump control status 1. Current (Amps) 2. Volts (VAC) 3. Power (kW) 4. Head 5. Flow

x. The pump logic controller shall be suitable for indoor or outdoor applications and shall be capable of being integrated with Intelligent Variable Speed pumping units for pumping packages approved to UL 778 & CSA STD C22.2 No 108 standards and also suitable for wall mounting with separate Intelligent Variable Speed pumping units and stand-alone pump controls.

y. The controller shall have 3-levels of password security, first level to view only (No password required); the second level is for field adjustable parameters and the third level for factory/commissioning setup parameters.

z. The controller shall stage the pumping units to ensure optimum pumping energy usage and shall sequence the pumps starting order, including any standby unit.

aa. The controller shall be fed with a power supply from each pumping unit controls in the control ‘daisy-chain’ so that a loss of power to any pump unit controls will not affect the controller pumping operation. Should the controller go off-line, all pumps in auto-mode will operate together to provide the correct system flow needs. Staging of the units will resume as the controller is brought back online.

bb. The integrated controller shall be capable of being easily integrated on any other pumping unit should the need occur. Simple mounting in pre-designed location and wiring will be all that is required.

Performance and Operating Logic cc. The pump logic controller shall determine the most efficient combination of

operating pumps, and pump operating speed based from the individual pump controls input.

dd. The pump logic controller shall respond to the system load flow needs by adjusting either the number of operating pumps, or the speed of the operating pumps.

ee. The pump logic controller shall continuously monitor the system requirements and ensure that the operating point is maintained on the control curve to meet the system needs with optimized pumping energy usage.

ff. The pump logic controller shall sequence the pumps based on a field adjustable interval of operating hours. The controls shall incorporate embedded logic to prevent hunting, pump flow surge, and motor overloading. The controller logic shall incorporate an adjustable PID control loop.

gg. Should any pumping unit or pumping unit controller fail, the appropriate alarm signal shall be activated. In the place of the failed assembly, a standby pumping unit shall be operated in variable speed mode, or the next pump will start if there is no standby.

hh. The controller shall have hand-off-automatic (H-O-A) control and should provide the option for a remote on/off signal by a BMS communication signal.

ii. The pump logic controller shall be self-prompting. All messages shall be displayed in plain English. The operator interface shall have multi-fault memory and recall on-screen help functions, and separate user screens for overview, pump and setup.

jj. The pump logic controller shall automatically disable any flow signals that are not within limits and alert the operator of a possible control failure.

kk. The pump logic controller shall have the system design flow, system design head and minimum head limit entered as field adjustable parameters, factory loaded. The default for the minimum head is 40% of the design head.

ll. Operator Screens i. Source of control: local or remote.

ii. Controller status: on/off. iii. Pump information: running/off/alarm, HOA status, pump ID 1, pump

ID 2, stand-by, etc. iv. Individual pump controls information: speed, amps, power, volts AC,

flow and head v. Set point and error of flow and head

vi. Individual cumulative pump hours of operation vii. System set-point and error

mm. Alarm Screens i. Alarms with time stamp

ii. Alarm help iii. Diagnostic indicating status (ok or bad) of PLC, memory, network and

communication, PLC Software version nn. Setup Screens

i. Level 0. No password, allows view only access ii. Level 1. Allows modification of all parameters, except pump PID and

BMS setup. Allows Restoring previously saved values

iii. Level 2. Allows modification of all parameters. Allows saving and restoring all parameters

iv. Levels 1 & 2 are password protected oo. BMS communication (Optional)

i. The controller shall be capable of serial communication with a BMS [Optional] with either of the following protocols:

1. Modbus RTU 2. BACnet MS/TP 3. LonWorks

ii. The following points will be available through all protocols: 1. Total flow 2. Head 3. Total real-time power consumption 4. Pump speed 5. Individual pump run status 6. Alarm 7. Wire to water system efficiency 8. Number of pumps operating 9. Lead pump ID 10. Remote start/stop 11. Controller on/off status 12. Pump controls information: running/off/alarm, HOA, duty 1,

duty 2, stand-by, etc. 13. Pump controls information: speed, current, power, Volts AC,

flow and head 14. Pump hours of operation 15. Head and flow Set point

C Pipe work

a. The scope shall comprise the supply, installation of pipe, fittings, valves etc. and testing and balancing the complete system.

b. Pipes i. All piping work shall conform to specifications and details given

below: - 1. Pipes up to 150 NB shall be MS ERW grade ‘C’ Medium class

beveled end by 35for welding and as per IS:1239 Part-I. 2. Above 150 NB to 250 NB the pipe shall be MS ERW as per

IS:3589. 3. Above 250 NB the pipes shall be MS ERW as per IS:3589 and

wall thickness shall conform to IS:226-1975 and 2062-1980 and as indicated in the Schedule of Work.

ii. Pipe sizes shall be selected with water velocity not exceeding 2.5 Meter/Second. The maximum friction in pipe shall not exceed 5 Meter per 100 Meter.

c. Fittings i. The dimensions of the fittings shall conform to IS:1239 – Part II (as per

latest amendment). All bends up to and including 150mm dia shall be

ready made of heavy duty wrought steel of appropriate class. All fittings such as branches, reducers etc. in all sizes shall be fabricated from pipe of same dia and thickness and its length shall be at least twice the diameter of the pipe.

ii. All bends in sizes 200mm to 450mm dia shall be fabricated from pipes of same diameter and thickness with a minimum of 4 sections.

iii. Blank ends are to be formed with flanged joints and 6mm thick blank between flanged pair.

d. Flanges i. All flanges shall be of mild steel as per IS: 6392/71(as per latest

amendment) and shall be slip-on type welded to the pipes. Flange thickness shall be to suit class-II pressure.

ii. Flanges may be tack welded into position, but all final welding shall be done with joints dismounted. 3mm thick gaskets shall be used with all flanged joints. The gaskets shall be fiber reinforced rubber as approved by Engineer-in-charge. Special adhesive compound shall be used between flanges of air & gas lines. All threaded valves shall be provided with nipples and flanged pair on both sides to permit flanged connection for removal of valves from main line for repair/replacement

e. Valves i. Balancing valves

1. All balancing valves up to and including 80mm dia shall be in gun metal screws type construction. The valves of 100mm dia and above shall be in cast iron flanged end construction. The valve shall have stainless steel disc with special erosion/corrosion proof sealing. The valves shall be capable of delivering metered quantity of water and subsequently function as isolating valve. All valves shall have built-in pressure drop measuring facility to ascertain water flow rate. The valve shall have temper proof adjustable and lockable arrangement for required water quantity after commissioning. The valves shall be complete with drain cock, pressure test cock etc. The valve shall be to minimum requirement of IS: 778 class-1. The Balancing Valves shall conform to Class PN-16.

ii. Butterfly valves 1. All BFV of 50mm dia and above shall be flanged type having

cast iron body with black nitrile rubber seat and conforming to PN-16 as per IS:13095. Flanges shall be as per IS:6392 Table “E”. Valves of sizes 32mm and above diameter shall be made of cast iron epoxy coated disc, Nitrile seat and SS:410 stem and Teflon bush. Valves of size 150mm NB and above shall have worm gear operation. All valves shall be supplied with factory test reports and manufacturer must have test facilities at their works.

iii. Miscellaneous valves:

1. All gauge cocks shall be of gun metal plug type, complete with siphon (brass chrome plated). All drain valves shall be gun metal with one end extended up to drain.

f. Jointing i. All pipelines shall be welded type except GI piping, which shall have

screwed joints. Pipes up to 100mm dia shall have plain cut ends

welding. All pipes 125mm dia and above will be beveled by 35for welding.

g. Miscellaneous i. All piping to be provided to make the equipment connected,

complete and ready for regular and safe operation. Connect the equipment as per recommendation of manufacturer, as approved by Engineer-in-charge. Refer drawings and specifications to determine number and requirements of items of equipment requiring piping, such as bends, drain, relief etc. wherever equipment is provided with connections for such piping.

1. All condensate drainage to be pitched in the direction of flow to ensure proper drainage with floor trap to prevent leakage of air due to static pressure developed by AHU. Pitching shall be preferably 20mm per meter length but not less than 10mm per meter in any case. For draining the water from gland packing through the pumps may be similarly pitched.

2. Provide valves and capped connections for all low points in piping system. Provide for all risers, isolating valves and drain valves to permit repairs without interfering with rest of the system.

3. Take precautions to close ends of pipes to prevent debris entering the piping system.

4. Independent supports for pipes to be provided so that equipment is not stressed by piping weight.

5. Unions, if used shall be flanged type. Locate unions between shut off valves and equipment, as directed by Engineer-in-charge.

6. Provide shut off valves where indicated and for individual equipment, units at inlet and outlet to permit unit removal for repairs without interfering with the remaining system. By-pass line and stop valves shall be provided for all automatic control valves as specified. All valves to be located for easy access and operation. Cut the pipes accurately according to measurements established at the site and putting these at places without forcing.

7. Pipe supports shall be adjustable for height and given prime coat with rust preventive paint and finished with grey paint as approved by Engineer in charge. Spacing of pipe supports shall not be more than as specified below:

Nominal pipe size (in mm) Spacing in Meters

15 1.25

20 & 25 2.00

32, 40, 50 & 125 2.5

80, 100 & 125 2.5

150 & above 3.00

8. Extra supports shall be provided at the bends, and heavy

fittings like valve to avoid undue stress on the pipes. Pipe hangers shall be fixed on walls and ceiling by means of approved metallic dash fasteners.

9. Where pipes are to be buried underground these should be coated with one coat of bituminous paint and coating and wrapping as per specification. The top of the pipe shall not be less than 75cms from the ground level. Wherever this is not practical, permission of Engineer in charge shall be taken for burying the pipes at lesser depth. The pipes shall be surrounded on all sides by sand cushion of not less than 15cm. After the pipe have been laid and top sand cushion provided the trench shall be refilled with excavated soil. Excess soil shall be removed by the contractor from the site of work.

h. Hangers and supports i. Hangers and supports shall be provided and installed for all piping and

tubing, wherever indicated, required or otherwise specified. Wherever necessary additional hangers and supports shall be provided to prevent vibration or excessive deflection of piping or tubing. All hangers and supports shall be of steel. Hangers shall be supported from structural steel, concrete inserts & pipe racks, specially approved. No hanger equipment shall be suspended midway between steel joists and panel points. All pipes in AC Plant Room shall be supported from vertical structural steel and horizontal channels from floor.

i. Sleeves i. Pipe sleeves of 50mm larger than the pipe shall be provided wherever

pipe pass through walls. Where pipes are insulated, sleeve shall be larger enough to have ample clearance for insulation. Where pipes pass through walls or floor slab the space between pipe and sleeve shall be packed with lead wool. The center of pipes shall be in center of pipe sleeves and the sleeve shall be flush with the finished surface. Floor sleeves shall project 50mm above finished floor level.

j. Arrangement and alignment of piping i. All piping shall be arrangement and aligned in accordance with the

drawings as specified. Unless otherwise specified, the piping shall be installed in a uniform way, parallel to or perpendicular to walls or ceiling and all changes in direction shall be made with fittings. The horizontal piping shall be run at right angles and shall not run diagonally across rooms or other piping. Wherever possible all piping

shall be arranged to provide a maximum head room. All piping shall be installed as directly as possible between connecting points in so far as the work of other trade permits. Where interference occurs with other trade, whose work is more difficult to route, this contractor shall reroute his piping as required at the direction of Engineer in charge. All piping shall be carefully installed to provide for proper alignment, slope and expansion. The stresses in the pipe-lines shall be guided and pipes shall be supported in such a manner that pipe lines shall not creep, sag or buckle. Anchors and supports shall be provided wherever necessary to prevent any misalignment of piping. Small tubing, gauges, controls or other equipment installed on any apparatus, shall not be coiled or excessive in length, but shall be installed neatly, carefully bent at all changes of direction, secured in place and properly fastened to equipment at intervals to prevent sagging.

ii. The piping shall be grouped wherever possible and shall be installed uniformly in straight parallel lines in either vertical or horizontal positions. All tubing / capillaries shall be provided with PVC sleeves to save it against frictional cuts or damage due to vibration.

k. Expansion or contraction i. The contractor shall provide for expansion and contraction of all

piping installed by use of expansion loops. l. Testing

i. Piping shall be tested before connection to equipment. In no case piping, equipment or appliances be subjected to pressures exceeding their test rating. The tests shall be completed before applying insulation. Testing the segments will be permitted provided all open ends are first closed by blank offs or flanges. After tests have been completed, the system shall be drained and flushed 3 to 4 times and cleaned of all dust and debris. All piping shall be tested to hydraulic test pressure of at least two times the maximum operating pressure but not less than 10 Kg/sq.cm. for a period of not less than 24 hours. All leaks and defects in the joints revealed during testing shall be rectified to the satisfaction of Engineer in charge and test repeated till no leak or defect are found.

ii. All piping shall be tested in presence of Engineer in charge or his authorized representative. The dates for carrying out the test shall be intimated in advance to Engineer in charge and all equipment, labor and material required during the test shall be provided by the contractor. The test after rectification shall be repeated till the entire system is found satisfactory. The test can be carried out for a portion of piping to avoid hindrance in the work of insulation contractor.

iii. All water and condensate pipes shall be tested and proven tight under hydrostatic pressure of 10Kg/sq.cm. for a minimum period of 24 hours without drop in pressure. The contractor shall ensure proper noiseless circulation through all piping systems. If due to air lock proper circulation is not achieved, the contractor shall bear all

expenses for carrying out rectification work including finishing of floors, walls and ceiling damaged in the process of rectification