Screw Compressor Central Chiller
Chapter 3: Installation
22
Condenser Water Out
The return outlet, located at the chiller side or rear is connected to a cooling tower inlet, a
sewer or other approved discharge receiver.
x
A water regulating valve is an
optional
feature in the condenser water
out line.
x
Adjust the butterfly valve for the pressure drop that corresponds to the
model number of the chiller (Shown in the table below). Pressure drop
is equal to supply pressure minus return pressure. (If a water
regulating valve has been supplied,
adjustment is not required
.)
Water Side Pressure Drop
Condenser (each)
Evaporator (each)
Model
Number
Flow (gpm)
PD (psi)
Flow (gpm)
PD (psi)
RSW/R60
91
4.0
72
5.3
RSW/R75
102
4.7
90
4.5
RSW/R90
117
4.4
107
5.6
RSW/R100
150
5.5
123
3.9
RSW/R115
166
4.3
140
3.0
RSW/R145
196
4.1
175
4.8
RSW/R165
219
4.1
200
4.6
RSW/R195
278
4.7
232
6.0
High Pressure Cutout
This unit is equipped with an electro-mechanical safety feature which opens the control
circuit if the system condensing pressure exceeds a safe level. The table below lists the
manufacturer settings for this safety feature:
High pressure cutout setting
Model
psi
kPa
bars
Water and Remote air-cooled chilling stations
290 psi
2,000 kPa
20 bars
Note:
The high pressure cutout is a manual reset control, so you should reset it
once.
If the problem persists, call a refrigeration service technician to analyze the
problem and to reset the control.
Low Pressure Cutout
This encapsulated switch safety feature prevents the compressor suction pressure from
dropping below a pre-set point. It is factory set to open the control circuit when pressure
drops below a safe level of 15 psi. The chiller will restart when the suction pressure reaches
30 psi (206.9 kPa/2.1 bars). The table below lists the settings at which the control circuit will
be open or reset.
Opens control circuit @
Resets control circuit @
Model
psi
kPa
bars
psi
kPa
bars
Water-cooled and remote air-cooled
chilling stations
15 psi 103.4 kPa 1.0 bars 30 psi 206.9 kPa 2.1 bars
