McQuay HDC050 Installation Manual
Installation, Operating and Maintenance Manual
IOMM WSCWDC-3
Group: Chiller
Part Number: 736015426
Effective: October 2004
Supersedes: IOMM WSCWDC-2
The McQuay DISTINCTION SERIES ¥¥¥¥
Single/Dual Compressor Centrifugal Chillers
WSC/WDC 050, 063, 079, 087, 100, 126, Cooling Only
HSC/HDC 050, 063, 079, 087, 100, 126, Heat Recovery
Table of Contents
Introduction......................................................................................................4
General Description .............................................................................................................4
Application...........................................................................................................................4
Nomenclature.......................................................................................................................4
Installation........................................................................................................5
Receiving and Handling.......................................................................................................5
Location and Mounting........................................................................................................6
Water Piping.........................................................................................................................7
Field Insulation Guide........................................................................................................11
Physical Data and Weights.................................................................................................13
Oil Coolers.........................................................................................................................15
Oil Heater...........................................................................................................................18
Relief Valves ......................................................................................................................18
Electrical ............................................................................................................................19
Power Wiring.....................................................................................................................19
Remote Starter Display Wiring ..........................................................................................20
Control Power Wiring........................................................................................................21
Multiple Chiller Setup........................................................................................................25
Prestart System Checklist...................................................................................................27
Operation........................................................................................................28
Operator Responsibilities...................................................................................................28
MicroTech II Control......................................................................................................28
Capacity Control System....................................................................................................30
Surge and Stall...................................................................................................................33
Lubrication System.............................................................................................................33
Hot Gas Bypass..................................................................................................................34
Condenser Water Temperature...........................................................................................34
Maintenance...................................................................................................35
Pressure/Temperature Chart...............................................................................................35
Routine Maintenance..........................................................................................................35
Annual Shutdown...............................................................................................................38
Annual Startup.................................................................................................................... 39
Repair of System................................................................................................................40
Maintenance Schedule...................................................................................42
Service Programs...........................................................................................44
Operator Schools............................................................................................44
Warranty Statement.......................................................................................44
“McQuay" is a registered trademark of McQuay International
¤2003 McQuay International
2 Centrifugal Chillers IOMM WSCWDC-3
Information and illustrations cover the McQuay International products at the time of publication and we reserve the right to make
changes in design and construction at anytime without notice.
IOMM WSCWDC-3 Centrifugal Chillers 3
Introduction
General Description
McQuay Centrifugal Water Chillers are complete, self-contained, automatically controlled fluid
chilling units. Each unit is completely assembled and factory tested before shipment. Models
WSC/WDC are cooling-only and Models HSC/HDC are cooling with heat recovery accomplished in
a bundle of condenser tubes separate from the cooling tower tube bundle.
In the WSC and HSC series, each unit has one compressor connected to a condenser and evaporator.
The WDC and HDC series are equipped with two compressors operating in parallel on a single
evaporator and condenser. Information in this manual referring to WSC and WDC also applies to
HSC and HDC units except where specifically noted.
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 interlocks, etc. are required, thereby simplifying installation and increasing reliability.
Most necessary equipment protection and operating controls are factory installed in the control
panel.
The basic sizes of units are the 050 (048), 063, 076, 079, 087, 100 and 126. They provide a cooling
capacity range from 80 tons to 2500 tons. In this manual all references to the WSC models will
equally apply to other models unless specifically referenced otherwise.
Application
The procedures presented in this manual apply to the standard WSC/WDC family of chillers and
HSC/HDC heat recovery chillers. Refer to the Operating Manual, OM CentrifMicro II (latest
version available on www.mcquay.com), for details on operation of the MicroTech II unit
controller.
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
can affect the equipment warranty.
The standard limited warranty on this equipment covers parts that prove defective in material or
workmanship. Specific details of this warranty can be found in the warranty statement furnished
with the equipment.
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 on optimum entering water temperature and cooling tower fan control, consult
McQuay Product Manual PM WSC/WDC, Applications Section, available on www.mcquay.com.
Heat recovery models, HSC/HDC, basically operate the same as cooling-only units. The heat
recovery function is controlled externally to the chiller as explained later in this manual.
Nomenclature
W
D C 063
W = Water-cooled
H = Heat Recovery
D = Dual Compressor
S = Single Compressor
4 Centrifugal Chillers IOMM WSCWDC-3
Chiller Model, Based on
Impeller Diameter
Centrifugal Compressor
Installation
(6)
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 corners from the evaporator's rigging hole locations are shipped loose and should be
glued in place after the unit is finally placed. Neoprene vibration pads are also shipped loose.
Check that these items have been delivered with the unit.
If so equipped, leave the shipping skid in place until the unit is in its final position. This will aid
in handling the equipment.
Extreme care must be used when rigging the equipment to prevent damage to the control panels or
refrigerant piping. See the certified dimension drawings included in the job submittal for the
center of gravity of the unit. Consult the local McQuay sales office for assistance if the drawings
are not available.
The unit can be lifted by fastening the rigging hooks to the four corners of the unit where the
rigging eyes are located (see Figure 1). Spreader bars must be used between the rigging lines to
prevent damage to the control panels, piping and motor terminal boxes.
Figure 1, WSC Major Component Locations
Compressor Control
Panel, At Rear
Rigging
Locations
A vailable
Evaporator
Operator Interface
Unit Control
Panel
Panel
Rigging
Locations
(6) A vailable
Compressor Starter,
Mounting Optional
Condenser
IOMM WSCWDC-3 Centrifugal Chillers 5
f
Pum
p,
r
Rigging
Figure 2, WDC Major Component Location
Oil Sump,
Heaters
Eyes
Motor
Terminal Box
Rigging
Eyes
Condenser
Dual Relie
Common Oil
Cooler Wate
Connections
Valves
Lubrication &
Compressor
Control Boxes
Condenser
Note: Chilled water and condenser connection location can vary. Check markings on unit or
consult unit certified drawings for connection locations on specific units.
Location and Mounting
Clearance
The unit must be mounted on a level concrete or steel base and must be located to provide service
clearance at one end of the unit for possible removal of evaporator tubes and/or condenser tubes.
Evaporator and condenser tubes are rolled into the tube sheets to permit replacement if necessary. The
length of the vessel should be allowed at one end. Doors or removable wall sections can be utilized for
tube clearance. Clearance at all other points, including the top, is 3 feet (1 meter). The National Electric
Code (NEC) can require more clearance in and around electrical components and must be checked.
6 Centrifugal Chillers IOMM WSCWDC-3
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. Most WSC units have six mounting feet although only the outer four are
required. Six pads are shipped 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 is not 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 refr igerant and oil valves closed to isolate these fluids for
shipment. Valves must remain closed until start- up by the McQuay technician.
Nameplates
There are several identification nameplates on the chiller:
• The unit nameplate is located on the side of the Unit Control Panel. It has a Style No. XXXX
and Serial No. XXXX, both are unique to the unit and will identify it. T hese numbers should
be used to identify the unit for service, parts, or warranty questions. This plate also has the
unit refrigerant charge.
• Vessel nameplates are located on the evaporator and condenser. Along with other
information, they have a National Board Number (NB) and a serial number, either of which
identify the vessel (but not the entire unit).
• A compressor nameplate is located on the compressor itself and contains identification
numbers.
Water Piping
Water Pumps
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 (four-pole) pump motors.
Evaporator and Condenser Water Piping
All 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 size and type
required. A heat recovery chiller, HSC/HDC, (shown on the
right) has two sets of condenser piping; one for the tower, one for
the heating system.
The tower connections are always the inboard pair of
connections. In the figure to the right, the condenser connections
are “left-hand” when viewed from the front of the unit (Unit
Control Panel and Interface Panel side), so in this case, the righthand condenser connections would be for the tower.
If the condenser connections were on the other end (“righthand”), the tower connections would be the left-hand pair of
connections.
IOMM WSCWDC-3 Centrifugal Chillers 7
Important Notes on Welding
If welding is to be performed on the mechanical or flange connections:
1. Remove the solid-state temperature sensor and thermostat bulbs from the wells to prevent
damage to those components.
2. Properly ground the unit or severe damage to the MicroTech II unit controller can occur.
Water pressure gauge connection taps and gauges must be provided in the field piping at the inlet
and outlet connections of both vessels for measuring the water pressure drops. The pressure
drops and flow rates for the various evaporators and condensers are job specific and the original
job documentation can be consulted for this information. 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. The condenser is connected with the coolest water entering at the bottom to maximize
subcooling.
Note: W hen common piping is used f or both heating and cooling modes, care must be
taken to provide that water flowing throug h the evaporator cannot exceed 110°F which
can cause the relief valve to discharge ref r igerant or damage controls.
The piping must be supported to eliminate weight and strain on the fittings and connections.
Piping must also be adequately insulated. A cleanable 20-mesh water strainer must be installed in
both water inlet lines. Sufficient shutoff valves must 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 lines to signal the presence of
adequate water flow to the vessels before the unit can start. They also serve to shut down the unit
in the event that water flow is interrupted to guard against evaporator freeze-up or excessive
discharge pressure.
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.
Consult the manufacturer's data for the minimum flow rates required to close the switch.
Installation should be as shown in Figure 3 and detailed in the manufacturer’s installation
instructions.
Figure 3, Flow Switch Mounti ng
Flow direction marked
on switch
I in. (25mm) NPT flow
switch connection
Tee
8 Centrifugal Chillers IOMM WSCWDC-3
If flow switches, by themselves, are being used, electrical connections in the Unit Control Panel
must be made from the common T3-S terminal to terminal CF for the condenser switch and T3-S
to terminal EF for the evaporator switch. See Figure 12, Field Wiring Diagram on page 24. The
normally open contacts of the flow switch must be wired between the terminals. Flow switch
contact quality must be suitable for 24 VAC, low current (16ma). Flow switch wire must be in
separate conduit from any high voltage conductors (115 VAC and higher).
Alternatively, for a higher margin of protection, normally open auxiliary contacts in the pump
starters can be wired in series with the flow switches as shown in Figure 12, Field Wiring
Diagram on page 24.
CAUTION
Freeze Notice: Neither the evaporator nor the condenser is self-draining;
both must be blown out to help avoid damage from freezing.
The piping should also include thermometers at the inlet and outlet connections and air vents at
the 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, vibration 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 they can
be required where noise and vibration are critical.
Cooling Towers
The condenser water flow rate must be checked to be sure that it conforms to the system design.
Some form of temperature control is also required if an uncontrolled tower can supply water
below about 65°F (18°C). If tower fan control is not adequate, a tower bypass valve is
recommended. Unless the system and chiller unit are specifically for condenser bypass or
variable condenser flow is not recommended since low condenser flow rates can cause unstable
operation and excessive tube fouling.
The condenser water pumps must cycle on and off with the unit. See Figure 12, Field Wiring
Diagram on page 24 for wiring details.
Tower water treatment is essential for continued efficient and reliable unit operation. If not
available in-house, competent water treatment specialists can be contracted.
Heat Recovery Chillers
HSC/HDC heat recovery chillers control the chilled water leaving temperature. The cooling load
determines compressor loading and unloading, the same as in a conventional chiller. A heat
recovery chiller’s control algorithms are identical to a conventional cooling-only chiller.
The temperature of the hot water being supplied from the recovery condenser to the heating load
is established by manipulating the cooling tower water temperature. The 3-way cooling tower
bypass valve is controlled by the heating water inlet temperature to the recovery bundle of the
condenser. Based on the signal the 3-way valve gets from the heating hot water sensor, it will
bypass sufficient water around the tower to force the tower condenser water loop high enough for
the recovery bundle to produce the desired hot water temperature.
The chilled water and its control system do not “know” that the condensing pressure and
condenser water temperatures are being regulated in this manner.
IOMM WSCWDC-3 Centrifugal Chillers 9
Figure 4, Heat Recovery Schematic
A
HEAT LOAD
UXILIARY
HEATER
OPEN
CIRCUIT
TOWER
LEGEND
TC TEMPERATURE CONTROL POINT
PUMP
TC
RECOVERY
CONDENSER
TOWER
CONDENSER
EVAPORATOR
COOLING
LOAD
HEAT RECOVERY
CHILLER
TC
10 Centrifugal Chillers IOMM WSCWDC-3
Field Insulation Guide
Figure 5, Insulation Requirements, Cooling-only Units
IOMM WSCWDC-3 Centrifugal Chillers 11
12 Centrifugal Chillers IOMM WSCWDC-3
Physical Data and Weights
Evaporator
The standard insulation of cold surfaces includes the evaporator and non-connection water head,
suction piping, compressor inlet, motor housing, and motor coolant outlet line.
Insulation is UL recognized (File # E55475). It is 3/4" thick ABS/PVC flexible foam with a skin.
The K factor is 0.28 at 75°F. 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, or has been tested in accordance, with the following:
ASTM-C-177 ASTM-C-534 Type 2 UL 94-5V
ASTM-D-1056-91-2C1 ASTM E 84 MEA 186-86-M Vol. N
CAN/ULC S102-M88
Refrigerant-side design pressure is 200 psi (1380 kPa) on WSC/HSC units and 180 psi (1242 kPa)
on WDC/HDC units. Water-side is 150 psi (1034 kPa) on all.
In the event insulation is to be field-installed, none of the cold surfaces identified above will be
factory insulated. Required field insulation is shown beginning on page 11. Approximate total
square footage of insulation surface required for individual packaged chillers is tabulated by
evaporator code and can be found below.
Table 1, Evaporator Physical Data
Evaporator
Code
E1809 X 434 (197) 37 (138) 75 (7.0) 2734 (1239) 1
E1812 X 347 (158) 27 (103) 78 (7.2) 2370 (1075) 1
E2009 X 561 (254) 34 (164) 82 (7.6) 3026 (1371) 1
E2012 X 420 (190) 37 9139) 84 (7.8) 2713 (1231) 1
E2209 X 729 (331) 54 (206) 66 (6.1) 3285 (1488) 1
E2212 X 500 (227) 45 (170) 90 (8.3) 2877 (1305) 1
E2212 X 645 (291) 63 (240) 90 (8.3) 3550 (1609) 1
E2216 X 1312 (595) 79 (301) 144 (13.4) 4200 (1903) 1
E2412 X 1005 (456) 88 (335) 131 (12.1) 4410 (1999) 1
E2416 X 1424 (646) 110 (415) 157 (14.6) 5170 (2343) 1
E2609 X 531 (249) 54 (295) 76 (7.1) 2730 (1238) 1
E2612 X 708 (321) 72 (273) 102 (9.4) 3640 (1651) 1
E2612 X 925 (418) 101 (381) 102 (9.4) 4745 (2150) 1
E2616 X 1542 (700) 126 (478) 162 (15.0) 5645 (2558) 1
E3009 X 676 (307) 67 (252) 86 (8.0) 3582 (1625) 1
E3012 X 901 (409) 89 (336) 115 (10.6) 4776 (2166) 1
E3016 X 2117 (960) 157 (594) 207 (19.2) 7085 (3211) 2
E3609 X 988 (720) 118 (445) 155 14.4) 5314 (2408) 1
E3612 X 1317 (597) 152 (574) 129 (11.9) 6427 (2915) 1
E3616 X 3320 (1506) 243 (918) 239 (22.2) 9600 (4351) 2
E4212 X 1757 (797) 222 (841) 148 (13.7) 8679 (3937) 1
E4216 X 4422 (2006) 347 (1313) 264 (24.5) 12215 (5536) 2
E4220 X 4713 (2138) 481 (1819) 330 (30.6) 15045 (6819) 2
E4812 X 2278 (1033) 327 (1237) 169 (15.6) 10943 (4964) 2
E4816 X 4690 (2128) 556 (2106) 302 (28.1) 16377 (7429) 2
E4820 X 5886 (2670) 661 (2503) 377 (35.0) 17190 (7791) 2
Notes:
1. Refrigerant charge is approximate since the actual charge will depend on other variables. Actual charge will be shown on the unit
nameplate.
2. Water capacity is based on standard tube configuration and standard dished heads.
3. The evaporator charge includes the maximum condenser charge available with that evaporator and is therefore the maximum charge for
a total unit with the evaporator. Actual charge for a specific selection can vary with tube count and can be obtained from the McQuay
Selection Program. The program will not allow a selection where the unit charge exceeds the condenser pumpdown capacity.
WSC WDC
Refrigerant
Charge
lb. (kg)
Evaporator
Water
Capacity, gal (L)
Insulation
Area
Sq. Ft. (m
Vessel
2
)
Weight
lb. (kg)
Number
of Relief
Valves
IOMM WSCWDC-3 Centrifugal Chillers 13
Condenser
With positive pressure systems, the pressure variance with temperature is always predictable, and
the vessel design and relief protection are based upon pure refrigerant characteristics. R-134a
requires ASME vessel design, inspection and testing and uses spring-loaded pressure relief
valves. When an over pressure condition occurs, spring-loaded relief valves purge only that
refrigerant required to reduce system pressure to their set pressure, and then close.
Refrigerant side design pressure is 200 psi (1380 kPa) on WSC/HSC units and 225 psi (1552 kPa)
on WDC/HDC units. Water side design is 150 psi (1034 kPa) on all.
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. Dual compressor
units and single compressor units equipped with the optional suction shutoff valve can also be
pumped down into the evaporator.
Table 2, Condenser Physical Data
Condenser
Code
C1609 X 468 (213) 33 (125) 1645 (746) 2
C1612 X 677 (307) 33 (123) 1753 (795) 2
C1809 X 597 (271) 43 (162) 1887 (856) 2
C1812 X 845 (384) 44 (166) 2050 (930) 2
C2009 X 728 (330) 47 (147) 1896 (860) 2
C2012 X 971 (440) 62 (236) 2528 (1147) 2
C2209 X 822 (372) 73 (278) 2596 (1169) 2
C2212 X 1183 (537) 76 (290) 2838 (1287) 2
C2212 X 1110 (504) 89 (337) 3075 (1395) 2
C2216 X 1489 (676) 114 (430) 3861 (1751) 2
C2416 X 1760 (799) 143 (540) 4647 (2188) 2
C2609 X 1242 (563) 83 (314) 2737 (1245) 2
C2612 X 1656 (751) 111 (419) 3650 (1660) 2
C2616 X 2083 (945) 159 (603) 5346 (2425) 2
C3009 X 1611 (731) 108 (409) 3775 (2537) 2
C3012 X 2148 (975) 144 (545) 5033 (3383) 2
C3016 X 2789 (1265) 207 (782) 6752 (3063) 4
C3612 X 2963 (1344) 234 (884) 7095 (3219) 2
C3616 X 3703 (1725) 331 (1251) 9575 (4343) 4
C4212 X 3796 (1722) 344 (1302) 9984 (4529) 2
C4216 X 5010 (2273) 475 (1797) 12662 (5743) 4
C4220 X 5499 (2494) 634 (2401) 17164 (7785) 4
C4812 X 4912 (2228) 488 (1848) 12843 (5826) 4
C4816 X 5581 (2532) 717 (2715) 18807 (8530) 4
C4820 X 7034 (3191) 862 (3265) 23106 (10481) 4
Notes:
1. Condenser pumpdown capacity based on 90% full at 90°F.
2. Water capacity based on standard configuration and standard heads and can be less with lower tube counts.
3. See Relief Valves section for additional information.
WSC WDC
Pumpdown
Capacity lb. (kg)
Water
Capacity gal. (L)
Vessel Weight
lb. (kg)
Number of
Relief
Valves
Compressor
Table 3, Compressor Weights
Compressor Size
Weight lb. (kg)
14 Centrifugal Chillers IOMM WSCWDC-3
050 063 079 087 100 126
870 (390) 3200 (1440) 3200 (1440) 3200 (1440) 6000 (2700) 6000 (2700)
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