SRL Service Manual 
Revision 00 
July 2007 
 
Page 20 of 56 
 
3.2.9  Fan Pressure Switch (Air Cooled Models) 
 
Settings: On: 275 psig (19 barg), Off: 203 psig (14 barg). 
Controls operation of the condenser fan which keeps the pressure (and therefore 
temperature) of the refrigeration circuit within design limits.  Turns the fan on 
when the refrigerant pressure reaches 275 psig (19 barg) and off when it reaches 
203 psig (14 barg).
 
 
3.2.10  Water Regulating Valve (Water Cooled Models) 
Regulates the flow of water into the condenser to maintain a constant refrigerant 
pressure (and therefore temperature).  Adjustment at start up may be required 
depending on the cooling water temperature.
 
 
 
3.2.11  Hot Gas Bypass Valve 
 
Setting: Max: 66.7 psig (4.6 barg) Min: 62.4 psig (4.3 barg). 
Maintains a constant refrigerant pressure in the compressor suction line to account for changes in the 
heat load.  As the heat load into the dryer decreases, less heat is transferred to the refrigerant in the 
Air-to-Refrigerant Heat Exchanger, and so less refrigerant evaporates.  This causes the pressure in 
the compressor suction line to drop.  The Hot Gas Bypass Valve injects hot high pressure refrigerant 
from the compressor outlet into the suction line to keep it constant. 
For details on adjusting the Hot Gas Bypass Valve, refer to Section 12. 
 
 
 
SRL-250 to 1400 (60Hz)
SRL-220 to 520 (50Hz) 
SRL-1600 to 6000 (60Hz) 
SRL-630 to 1800 (50Hz)