Page 28
TABLE 12
SW 060 COOLING OPERATING PRESSURES
Entering Water Temp
Discharge
+10 psig
S 5
psig
59
F
260
135
77
F
328
140
86
F
357
144
TABLE 13
SW 060 HEATING OPERATING PRESSURES
Entering Water Temp
Discharge
+10 psig
S 5
psig
32
F
312
75
50
F
342
103
68
F
377
139
TABLE 14
SW 120 COOLING OPERATING PRESSURES
Entering
Water Temp
CIRCUIT 1
CIRCUIT 2
Dis +10
psig
Suc +5
psig
Dis +10
psig
Suc +5
psig
59
F
245
136
254
136
77
F
322
134
322
137
86
F
365
135
364
138
TABLE 15
SW 120 HEATING OPERATING PRESSURES
Entering
Water Temp
CIRCUIT 1
CIRCUIT 2
Dis +10
psig
Suc +5
psig
Dis +10
psig
Suc +5
psig
32
F
300
75
285
74
50
F
332
105
313
103
68
F
360
134
337
130
TABLE 16
SW 240 COOLING OPERATING PRESSURES
Entering
Water Temp
CIRCUIT 1
CIRCUIT 2
Dis +10
psig
Suc +5
psig
Dis +10
psig
Suc +5
psig
59
F
231
127
250
131
77
F
312
132
306
140
86
F
353
135
346
142
TABLE 17
SW 240 HEATING OPERATING PRESSURES
Entering
Water Temp
CIRCUIT 1
CIRCUIT 2
Dis +10
psig
Suc +5
psig
Dis +10
psig
Suc +5
psig
32
F
282
70
271
68
50
F
335
97
324
96
68
F
355
123
342
122
F-Compressor Controls
See unit wiring diagram to determine which controls are
used on each unit.
1- High Pressure Switch (S4, S7)
The compressor circuit is protected by a high
pressure switch which opens at 640 psig + 10 psig
(4413 kPa + 70 kPa) and automatically resets at 475
psig + 20 psig (3 138 kPa).
2- Low Pressure Switch (S87, S88)
The compressor circuit is protected by a loss of
charge switch. Switch opens at 40 psig + 5 psig (276
+ 34 kPa) and automatically resets at 90 psig + 5
psig (621 kPa + 34 kPa).
3- Crankcase Heater (HR1, HR2)
Units have compressors which contain a belly band
compressor oil heater which must be on 24 hours before
running compressors. Energize by setting thermostat so
that there is no cooling demand, to prevent compressor
from cycling, and apply power to unit.
4- Freezestats (S49, S50)
Switches de-energize compressors when indoor
coil temperature falls below 29
F (-2
C) to prevent
indoor coil freeze-up. Switches reset when indoor
coil temperature reaches 58
F (15
C).
5- Crankcase Heater Thermostat (S40, S162)
Switches de-energize crankcase heaters when
discharge temperature rises above 94°F (34.4°C).
Switch opens to energize crankcase heaters when
discharge temperature drops below 74°F (23.2°C).
Water Circuit Operation
When the compressor is energized the water flow control
valve will de-energize and spring-return open allowing
water flow. When the compressor de-energizes, the valve
is actuated closed, stopping the flow of water. The valve
opens in 10-15 seconds and closes in 30-40 seconds.
The automatic flow regulator manages the water flow to
the water-to-refrigerant coil. No g.p.m. adjustment is
required.
Freeze Protection
Consult with local and national governing bodies
when determining the water mixture used in the
water-to-refrigerant coil. Appropriate mixtures must
be used to prevent personal injury, product, or
property damage.
Each unit is equipped with a factory-installed S116
antifreeze controller to prevent damage to the refrigerant
to water coil. See figure 30. The controller is set to initiate
water compartment electric heat when compartment
temperature drops to 42°F (10°F above the freezing point
of water) and to circulate water if compartment
temperature continues to drop to 37°F (5°F above the
freezing point of water). When compartment temperature
rises to 42°F water circulation is discontinued. If
compartment temperature continues to rise electric heat
will de-energize at 47°F. See figure 31.
