Specifications

8 Centrifugal Chillers IMM WMC-2
Field Insulation
If the optional factory-installation of thermal insulation is not ordered, insulation should be field installed to
reduce heat loss and prevent condensation from forming. Insulation should cover the evaporator barrel, tube
sheet, and water heads, plus the suction line to the compressor flange and the compressor end bell opposite the
suction connection.
The optional factory-installed insulation of cold surfaces includes the evaporator and non-connection water
head, suction piping, compressor inlet, and motor housing.
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
Physical Data and Weights
Evaporator
Refrigerant-side design pressure is 200 psi (1380 kPa). Water-side is 150 psi (1034 kPa).
Approximate total square footage of insulation surface required for individual packaged chillers is tabulated
by evaporator code and can be found below. The suction elbow and compressor also require insulation.
Table 1, Evaporator Physical Data
WMC Model
Evaporator
Code
Tube
Length
Unit Refrigerant
Charge
lb. (kg)
Evaporator
Water
Volume, gal (L)
Insulation
Area
sq. ft. (m
2
)
Number of
Relief
Valves
145S, E2209 9 ft. 500 (227) 38 (145) 66 (6.1) 1
145D E2209
9 ft. 600 (272) 38 (145) 66 (6.1) 1
150D E2212
12 ft. 800 (363) 45 (170) 90 (8.3) 1
250D E2609
9 ft. 600 (272) 61 (231) 76 (7.1) 1
290D E2612
12 ft. 1100 (500) 72 (273) 102 (9.4) 1
Notes:
1. Refrigerant charge is for the entire unit and 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.
Condenser
With positive pressure systems, the pressure variance with temperature is always predictable, and the vessel
design and pressure 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 quantity of refrigerant required to reduce the
pressure to the valve’s set pressure and then close.
Refrigerant-side design pressure is 200 psi (1380 kPa). Water-side design is 150 psi (1034 kPa).
Table 2, Condenser Physical Data
WMC Model
Condenser
Code
Tube
Length
Maximum
Pumpdown
Capacity lb. (kg)
Water
Volume
gal. (L)
Number of
Relief Valves
145S, 145D C2009
9 ft. 724 (328) 47 (147) 2
150D C2012
12 ft. 971 (440) 62 (236) 2
250D C2209
9 ft. 883 (401) 61 (231) 2
290D C2212
12 ft. 1174 (533) 72 (273) 2
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.
4. See page 8 for unit operating, shipping and corner weights.