McQuay WPV250 Installation Manual
Installation, Operating and Maintenance Manual
IOMM WPV
WPV Centrifugal Compressor Chillers
WPV 240 to 430
220 tons to 430 tons (770 kW to 1500 kW)
Group: Chiller
Part Number: 736015421
Effective: October 2005
Supersedes: New
Table of Contents
Introduction...............................................................................................................3
General Description........................................................................................................................... 3
Application........................................................................................................................................ 3
Installation................................................................................................................. 4
Receiving and Handling....................................................................................................................4
Location and Mounting..................................................................................................................... 4
Location and Mounting..................................................................................................................... 5
Water Piping...................................................................................................................................... 5
System Water Volume........................................................................................................................ 7
Physical Data and Weights ................................................................................................................7
Evaporator......................................................................................................................................... 7
Condenser.......................................................................................................................................... 8
Oil Coolers ........................................................................................................................................ 8
Refrigerant Vent Piping ................................................................................................................... 10
Electrical.......................................................................................................................................... 11
Power Wiring...................................................................................................................................11
Control Wiring.................................................................................................................................12
Prestart System Checklist ................................................................................................................ 14
Operation .................................................................................................................15
Operator Responsibilities ................................................................................................................ 15
Standby Power.................................................................................................................................15
Nomenclature .................................................................................................................................. 15
Operating Limits..............................................................................................................................15
MicroTech II Control.......................................................................................................................16
Capacity Control System.................................................................................................................16
Lubrication System..........................................................................................................................18
Pressure Drops.........................................................................................................20
Dimensions...............................................................................................................22
WPV Chillers .................................................................................................................................. 22
Maintenance............................................................................................................. 26
R-134a Pressure/Temperature Chart................................................................................................26
Routine Maintenance....................................................................................................................... 26
Annual Shutdown ............................................................................................................................ 29
Annual Startup ................................................................................................................................. 29
Repair of System.............................................................................................................................30
Maintenance Schedule............................................................................................32
Service Programs.....................................................................................................34
Operator Schools..................................................................................................... 34
McQuay" is a registered trademark of McQuay International
"Information and illustrations cover the McQuay International product at the time of publication and we reserve the right to make changes in
design and construction at anytime without notice".
©
2002 McQuay International
2 Centrifugal Chillers IOMM WPV
Introduction
General Description
The McQuay WPV Centrifugal Water Chillers are complete, self-contained, automatically controlled fluid
chilling units. Each unit is completely assembled and factory tested before shipment.
In the WPV series, each unit has one compressor connected to a condenser and evaporator and is equipped with
a factory-mounted starter.
The chillers use refrigerant R-134a to reduce the size and weight of the package compared to negative pressure
refrigerants and since R-134a operates at a positive pressure over the entire operation range, no purge system is
required.
The controls are pre-wired, adjusted and tested. Only normal field connections such as piping, electrical and
pump interlocks, etc. are required thereby simplifying installation and increasing reliability. All necessary
equipment protection and operating controls (except flow switches) are factory installed in the control panel.
The sizes of units are the WPV 240, 280, 290, 320 350, 390, 410, and 430 providing a capacity range from 220
tons to 430 tons.
Application
The operation and maintenance procedures presented in this manual apply to the standard WPV family of
chillers. Refer to the Operating Manual, OM CentrifMicro II (latest version) for details pertaining to operation
of the MicroTech II£ control.
All McQuay centrifugal chillers are factory tested prior to shipment and must be initially started at the job site
by a factory trained McQuay service technician. Failure to follow this startup procedure will affect the
equipment warranty.
The standard warranty on this equipment covers parts that prove defective in material or workmanship and the
labor to replace them. Specific details of this warranty can be found in the warranty statement furnished with
the equipment. Refrigerant are not included unless specifically ordered as an option.
Cooling towers used with McQuay centrifugal chillers are normally selected for maximum condenser inlet water
temperatures between 75°F and 90°F (24°C and 32°C). Lower entering water temperatures are desirable from
the standpoint of energy reduction but a minimum does exist. For recommendations for optimum entering water
temperature and cooling tower fan control, consult McQuay Product Manual PM WPV, Applications Section.
IOMM WPV Centrifugal Chillers 3
Installation
Receiving and Handling
The unit should be inspected immediately after receipt for possible damage.
All McQuay centrifugal water chillers are shipped FOB factory and all claims for handling and shipping
damage are the responsibility of the consignee.
Insulation on the upper corners of the evaporator at the rigging holes is shipped loose and should be glued in
place after the unit is finally placed. Neoprene vibration pads are also shipped loose. Check to be sure that
these items are delivered with the unit.
The units are shipped without skids and means for rolling/sliding units must be supplied in the field.
Extreme care should be used when rigging the equipment to prevent damage to the control center, or
refrigerant piping. See certified dimension sheets for the center of gravity of the unit.
The unit can be lifted by fastening the rigging hooks to the four outside corners of the unit where the rigging
eyes are located (see Figure 1). Spreader bars should be used between the rigging lines to prevent damage.
Rigging
Locations
4 Each End
Figure 1, Unit Components
Operator
Interface Panel
Unit Control
Panel
Evaporator
4 Centrifugal Chillers IOMM WPV
Motor
Starter
Condenser
Location and Mounting
Clearance
The unit should be mounted on a level concrete or steel base and should be located so as to provide service
clearance at one end of the unit for possible removal of evaporator tubes and/or condenser tubes. Tube
clearances required are 14 feet (4.3 meters) for units with 12-foot (3.7 meters) long shells, and 11 feet (3.3
meters) for units with 9-foot (2.7meters) long shells. Evaporator/condenser tubes are rolled into the tube
sheets to permit replacement if necessary. Clearance at all other points, including the top, is 3 feet (1 meter).
Vibration Pads
The shipped loose neoprene vibration pads should be located under the corners of the unit (unless the job
specifications state otherwise). They are installed to be flush with the sides and outside edge of the feet.
Some WPV uni ts ha ve six mounting feet altho ugh o nly the oute r four are req uired . Six p ads are shi ppe d and
the installer can place pads under the middle feet if desired.
Mounting
Make sure that the floor or structural support is adequate to support the full operating weight of the complete
unit.
It will not be necessary to bolt the unit to the mounting slab or framework; but should this be desirable, 1 1/8"
(28.5 mm) mounting holes are provided in the unit support at the four corners.
Note: Units are shipped with refrigerant and oil valves closed to isolate thes e fluids for shipment.
Valves must remain closed until start-up by McQuay technician.
Water Piping
Vessel Drains at Start-up
The unit is tilted and dr ained of water in the factory and shipped with open drain valves in each head. .Be
sure to close the valves prior to filling the vessel with fluid.
Water Pumps
Note: Avoid the use of 3600/3000 rpm (two-pole motor) pump motors.
It is not uncommon to find that these pumps operate with objectionable noise and vibration.
It is also possible to build up a frequency beat due to the slight difference in the operating rpm of the pump
motor and the McQuay centrifugal motor. McQuay encourages the use of 1750/1460 rpm or four-pole pump
motors whenever possible.
Evaporator and Condenser Water Piping
All WPV evaporators and condensers come standard with groove-type nozzles for Victaulic couplings (also
suitable for welding) or optional flange connections. The installing contractor must provide matching
mechanical connections of the sizes given in the system dimension and capacity tables.
Important Notes on Welding
1. If welding is to be performed on the mechanical or flange connections, the solid-state
temperature sensor and thermostat bulbs must be removed from the wells to prevent damage to
those components.
2. The unit must be properly grounded or severe damage to the MicroTech II controller can occur.
Small water pressure test valves or pipe plugs are provided at both the inlets and outlets of the vessel heads.
The test valves permit the water flow pressure drops to be checked. The pressure drops and flow rates for the
various evaporators and condensers are shown on pressure drop curves contained in this manual. Refer to the
nameplate on the vessel shell for identification.
Be sure that water inlet and outlet connections match certified drawings and stenciled nozzle markings.
IOMM WPV Centrifugal Chillers 5
• The condenser is connected with the coolest water entering at the bottom to maximize subcooling.
• The evaporator inlet is always on the left when looking at the nozzles from the connection end.
CAUTION
When co mmon piping is used in connection with a heating system, care should be taken to insure
that water flowing through the evaporator cannot exceed 110°F which can cause the relief valve to
discharge refrigerant or damage controls.
The piping should be supported to reduce the weight and strain on the fittings and connections. Piping should
also be adequately insulated. A cleanable 20-mesh water strainer should be installed at both inlets. Sufficient
shutoff valves should be installed to permit draining the water from the evaporator or condenser without
draining the complete system.
Flow Switch
A water flow switch must be mounted in the leaving water line of the evaporator and condenser to insure that
there will be adequate water flow before the unit can star t. This will guard against slugging the compressors on
start-up. It also serves to shut down the unit in the event that water flow is interrupted.
A flow switch is available from McQuay under Part Number 017503300. It is a "paddle" type switch and
adaptable to any pipe size from 1 inch to 8 inches.
The flow switch should be adjusted to open at half the normal flow rate for the vessel. Follow the instructions
that come with the flow switch.
Figure 2, Flow Switch Mounting
Flow direction marked
on switch
I in. (25mm) NPT flow
switch connection
Tee
The flow switch connections to the unit control panel must be according to the Field Wiring Diagram, Figure 7,
found on page 13. Install the switch according to manufacturer's instructions included with it.
CAUTION
Freeze Notice: Neither the evaporator nor the condenser is self-draining;
both must be blown out.
The piping should also include thermometers at the inlet and outlet connecti ons and air vents at t he high points.
The water heads can be interchanged (end for end) so that the water connections can be made at either end of
the unit. If this is done, new head gaskets must be used and control sensors relocated.
In cases where the water pump noise can be objectionable, isolation sections are recommended at both the inlet
and outlet of the pump. In most cases, it will not be necessary to provide vibration eliminator sections in the
condenser inlet and outlet water lines; but where noise and vibration are critical (for example, where a pipe
chase goes through walls adjoining living quarters in a n apartment building), they can be re quired.
Where a cooling tower is used to supply condenser water, a flow-balancing valve is required. Some form of
temperature control is required if tower water becomes too cold.
6 Centrifugal Chillers IOMM WPV
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 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 products 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, and loss of temperature control.
For normal comfort cooling applications where the cooling load changes relatively slowly, we recommend a
minimum system volume of three minutes times the flow rate (gpm). For example, if the design chiller flow
rate is 1000 gpm, we recommend a minimum system volume of 3000 gallons (1000 gpm x 3 minutes).
For process applications where the cooling load can change rapidly, additional system water volume is
needed. A process example would be a quench tank where the load would be stable until the hot material is
dipped into the water tank. Then, the load would increase drastically. Large storage capacity will usually be
required for this type of application.
System volume = {1000 gpm x 3 minutes} + {(5 increment of 10% increase) x (3 minutes) x 1000 gpm} =
18,000 gallons
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 suggestions, the possibility of
problems increases. We believe that these guidelines should be an industry standard and not just
recommendations from McQuay.
Physical Data and Weights
Evaporator
The insulation provided by McQuay of cold surfaces includes the evaporator and non-connection water
head, suction piping, compressor inlet, motor housing, and motor coolant suction line.
The insulation used is UL recognized. It is 3/4" thick vinyl nitrate pol ymer having a K factor of 0.2 8 at
75°F. The sheet insulation is fitted and cemented in place forming a vapor barrier, then painted with a
resilient epoxy finish that resists cracking.
The insulation complies to appropriate requirements or has been tested in accordance with the following:
HH-I-573 (GSA-FSS) ASTM-D-1149 ASTM-C-177
ASTM-C-534 ASTM-D-1056 UL 94-5V
ASTM-C-355
Refrigerant side design pressure is 200 psi (1380 kPa). Water side design pressure is 150 psi (1034 kPa)
with 300 psi (2068 kPa) available as an option.
Table 1, Evaporator Physical Data
WPV
Model
240 482 (219) 39 (146) 66 (6.1) 3285 (1488)
250 482 (219) 39 (146) 66 (6.1) 3285 (1488)
280 853 (388) 73 (275) 102 (9.4) 4745 (2150)
290 853 (388) 73 (275) 102 (9.4) 4745 (2150)
320 853 (388) 73 (275) 102 (9.4) 4745 (2150)
350 853 (388) 73 (275) 102 (9.4) 4745 (2150)
390 853 (388) 73 (275) 102 (9.4) 4745 (2150)
410 853 (388) 73 (275) 102 (9.4) 4745 (2150)
430 1113 (505) 89 (336) 115 (10.6) 4776 (2166)
Refrigerant
Charge
lb (kg)
Water
Volume,
gal (L)
Insulation
Area
Sq Ft (m
2
)
Vessel
Weight
lb (kg)
Number
of Relief
Valves
1 22 (559) 9 (2743)
1 22 (559) 9 (2743)
1 26 (660) 12 (3660)
1 26 (660) 12 (3660)
1 26 (660) 12 (3660)
1 26 (660) 12 (3660)
1 26 (660) 12 (3660)
1 26 (660) 12 (3660)
1 30 (762) 12 (3660)
Diameter
in. (mm)
Length
Ft. (mm)
IOMM WPV Centrifugal Chillers 7
Condenser
Refrigerant side design pressure is 200 psi (1380 kPa). Water side design is 150 psi (1034 kPa) with
300 psi (2068 kPa) available as an option.
Table 2, Condenser Physical Data
WPV
Model
240 728 (330) 42 (160) 1896 (860)
250 728 (330) 42 (160) 1896 (860)
280 1183 (537) 76 (290) 2838 (1287)
290 1183 (537) 76 (290) 2838 (1287)
320 1183 (537) 76 (290) 2838 (1287)
350 1183 (537) 76 (290) 2838 (1287)
390 1183 (537) 76 (290) 2838 (1287)
410 1183 (537) 76 (290) 2838 (1287)
430 1656 (751) 93 (353) 3650 (1660)
Pumpdown
Capacity
lb (kg)
Pumpdown
To facilitate compressor service, all McQuay centrifugal chillers are designed to permit pumpdown
and isolation of the entire refrigerant charge in the unit’s condenser. No separate pumpout receiver is
required.
Water
Volume
gal (L)
Vessel
Weight
lb (kg)
Number of
Relief
Valves
2 20 (508) 9 (2743)
2 20 (508) 9 (2743)
2 22 (559) 12 (3660)
2 22 (559) 12 (3660)
2 22 (559) 12 (3660)
2 22 (559) 12 (3660)
2 22 (559) 12 (3660)
2 22 (559) 12 (3660)
2 26 (660) 12 (3660)
Diameter
in. (mm)
Length
Ft. (mm)
Oil Coolers
McQuay WPV centrifugal chillers have a factory-mounted water-cooled oil cooler with a temperature
controlled water-regulating valve and a solenoid valve.
Cooler cooling water connections are located below the compressor and are shown on the specific unit
certified drawings.
Field water piping to the cooler inlet and outlet connections must be installed according to good piping
practices and should include stop valves to isolate the cooler for servicing. A 3/4" minimum cleanable filter
(40 mesh maximum), and drain valve or plug should also be field installed. The water supply for the oil
cooler should be from the chilled water circuit or from an independent source such as city water. When using
chilled water it is important that the water pressure drop across the evaporator is greater than the pressure
drop across the oil cooler or insufficient oil cooler flow will result. If the pressure drop across the evaporator
is less than the oil cooler, the oil cooler must be piped across the chilled water pump provided that its
pressure differential is sufficient. The water flow through the oil cooler will be adjusted by the unit's
regulating valve so that the temperature of oil supplied to the compressor bearings (leaving the oil cooler) is
between 80°F and 110°F (27°C and 43°C).
Compressors using chilled water for oil
cooling will often start with warm "chilled
water" in the system until the chilled water
loop temperature is pulled down. Data given
here is for that condition. With cooling
water in the 40°F to 55°F (4°C to 13°C)
range considerably less water will be used
and the pressure drop will be greatly reduced.
Oil Cooler Data
Unit Model
All 12 32 80.0 87.0
Note:
1. Pressure drops include valve on the unit.
Flow
(gpm)
Press.
Drop (ft)
Water Temp.
Inlet (°F) Outlet (°F)
When supplie d with city water, the o il piping shoul d discharge thro ugh a trap into an o pen drain to prevent
draining the c oo le r b y sipho ning. T he c ity water c an a lso be used fo r co o ling t ower make up b y disc hargi ng it
into the tower sump from a point above the highest possible water level.
8 Centrifugal Chillers IOMM WPV
NOTE: Particular attentio n must be paid to chillers with variable chilled water flow through the evapora tor.
N
The pressure drop available at low flow rates can very well be insufficient to supply the oil cooler with
enough water. In this case an auxiliary booster pump can be used or city water employed.
CONNECTION SIZES: WPV cooler connection sizes are 3/4 in. FPT.
Figure 3, Oil Cooler Piping Across Chilled Water Pump
PUMP
CHILLER
R
SOLENOID
VALVE
S
STOP
VALUE
DRAIN VALVE
OR PLUG
STOP
VALVE
STRAINER
MAX. 40 MESH
OIL COOLER
Figure 4, Oil Cooler Piping With City Water
R
OIL COOLER
S
Relief Valve
Reservoir
Solenoid
Valve
Temperature
Control Valve
Oil
SOLENOID
VALV E
WATER
SUPPLY
STOP
VALVE
STRAINER
MAX. 40
MESH
DRAIN VALVE
OR PLUG
Figure 5, Oil Cooler Connections, WPV Units
COOLING TOWER
COOLING TOWER MAKEUP
DISCHARGE ABOVE
HIGHEST POSSIBLE
WAT ER LEVEL
OPEN
DRAI
Oil Pump
Contactor
Oil Pump
Capacitor
Compressor
Microprocessor
Controller
Inlet
Connection
Outlet
Connection
IOMM WPV Centrifugal Chillers 9
Refrigerant Vent Piping
C
As a precaution, each system is equipped with
pressure relief valves located on the condenser,
evaporator, and oil sump vessel for the purpose of
relieving excessive refrigerant pressure to the
atmosphere. Most codes require that relief valves be
vented to the outside, and this is a desirable practice
for all installations.
Note: Remove plastic shipping plugs (if
installed) from the inside of the valves prior to
making pipe connections . Whenever vent piping
is installed, the lines should be run in accor dance
with local code requirements; where local codes
do not apply, ANSI/ASHRAE Standard 15-1994
code recommendations should be followed.
The condenser design incorporates two relief valves
(one set) with a three-way shutoff valve separating the
two valves (see Figure 6, Condenser Relief Valve Set).
One valve remains in the system at all times and the
second valve acts as a standby.
If one relief valve of the two-valve set fails, the shutoff valve can be used to isolate the faulty relief valve,
while the other valve provides pressure protection.
Figure 6, Condenser Relief Valve Set
When piping the vent line to a dual valve set, it can be sized for one relief valve and piped to both valves.
Connections are 1 inch FPT.
Vent piping is sized for only one valve of the set since only one can be in operation at a time. In no case
would a combination of evaporator and condenser sizes require more refrigerant than the pumpdown
capacity of the condenser. Condenser pumpdown capacities are based upon ANSI/ASHRAE Standard 151992 recommendations of 90% full at 90°F (32°C). To convert values to the older ARI standard, multiply
pumpdown capacity by 0.888.
Relief Valve Pipe Sizing
Relief valve pipe sizing is based on the discharge capacity for the given evaporator or condenser and the
length of piping to be run. Discharge capacity for HFC-134a vessels is calculated as follows:
Where: C=Minimum discharge capacity, lbs of air/min
D=Vessel diameter, in.
L=Vessel length, ft.
10 Centrifugal Chillers IOMM WPV
xDxL= 0133.
Example: WPV 240 evaporator, HFC-134a Refrigerant, 75 equivalent feet of piping
min/3.26922133.0 airofLbsxxC ==
From the table below, 75 feet of piping for 26.3 lb. of air/min. at 200 psig valve setting requires a 1.25"
diameter pipe.
Table 3, Discharge Capacity, lbs of Air/Min
EQUIVALENT DIAMETER STANDARD WALL IRON PIPE
LENGTH OF 1” (25mm) 1.25” (32mm) 1.5” (38mm) 2” (50mm) 2.5” (64mm ) 3” (76mm)
DISCHARGE RELIEF VALVE PRESSURE SETTNG (psi)
PIPING, FT. (m) 200 200 200 200 200 200
50 (15.2) 24.1 48.2 66.6 131.6 204.9 354.5
75 (22.9) 19.7 39.4 57.9 107.3 169.3 289.6
100 (30.5) 17.1 29.0 49.9 92.9 145.8 250.3
150 (45.7) 14.0 27.8 40.5 75.7 118.5 204.9
200 (61.0) 12.1 24.1 35.3 65.7 102.5 177.4
300 (91.4) 10.0 19.7 28.7 53.6 85.0 144.6
Note: Standard relief valve settings:
1. Evaporator=200 psig, condenser=200 psig
NOTE: Per ASHRAE Standard 15, the pipe size can not be less than the relief device, meaning a
minimum 1" diameter pipe is required. The discharge from more than one relief valve can be run
into a common header, the area of which shall not be less than the sum of the areas of the
connected pipes. For further details, refer to ASHRAE Standard 15. The c ommon header can be
calculated by the formula:
05
D
Common
122
22
....
§
¨
DDD
=+
©
.
·
¸
n
¹
NOTE: The above information is a guide only. Consult local codes and/or latest version of ASHRAE
Standard 15 for sizing data.
Electrical
Wiring, fuse and wire size must be in accordance with information located in the electrical data.
Important: The voltage to these units should be within the limitation of +10% of nameplate. The voltage
unbalance between phases must not exceed 2% per NEMA MG-1, 1998 Standard. It is most important that the
unbalance between phases be kept at a minimum.
Power Wiring
WARNING
Qualified and licensed electricians must perform wiring. Shock hazard exists.
The McQuay start-up technician will determine proper phase sequence.
NOTE: Connections to terminals must be made with copper lugs and copper wire.
Under no c ir c umstances sho uld a co mpre sso r b e br o ught up t o sp e ed unle ss p ro p e r se q uence and r o ta tio n ha ve
been established. Serious damage can result if compressor starts in wrong direction.
Unit Mounted Starter Power Wiring
All units are supplied with a factory-wired and mounted starter equipped with ambient compensated quick trip
overloads. Wiring, fuse and wire size must be in accordance with information located in the electrical data
supplied with the unit or the electrical data pertaining to your unit.
IOMM WPV Centrifugal Chillers 11
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