Sterling GP Series Refrigerator User Manual


 
GP Series Portable Chillers Chapter 2: Functional Description 10 of 44
High Pressure Cutout
This electro-mechanical cutout device opens the compressor control circuit if the refrigeration
system compressor discharge pressure exceeds 575 psi..
Note: The high-pressure cutout is a manual reset device typically mounted on the
compressor discharge line inside the mechanical cabinet. Call a refrigeration
service technician to analyze the problem and reset the control.
Low Pressure Cutout (no switch but done through the transducer)
This electro-mechanical cutout device opens the compressor control circuit if refrigeration
system compressor suction pressure drops below 15 psi. It automatically resets when
refrigerant suction pressure reaches 30 psi.
Note: The low pressure cutout is an automatic reset device typically mounted on the
compressor suction line inside the mechanical cabinet. Call a refrigeration
service technician to analyze the problem and reset the control.
Flow Switch
The thermal dispersion flow switch cutout device, mounted in the process piping, shuts down
the chiller if it senses that the water/glycol flow rate through the evaporator has dropped
below an acceptable level. The flow switch opens the control circuit and shuts down the
pumps and the chiller.
Remote Start/Stop Interlock
An additional contact is provided to allow the remote starting or stopping of the chiller. To
use this feature, remove the jumper between terminals X1 and 1, and supply a switch or dry
contact interlock connected in series between these two terminals. Refer to the schematic
inside the control enclosure door.
2-5 Optional Features
Options marked with “*” indicate options that can be factory installed or retrofitted in the
field.
Automatic Water Make-Up*. Not available on chillers less reservoir tank. Includes an
electric water solenoid valve, a level sensing pressure switch mounted in the reservoir tank,
and the necessary internal piping to connect the chiller to a make-up water source. See
Appendix for typical piping diagrams.
Caution! Customer piping must provide backflow protection and venting of tank to
atmosphere to prevent over-pressurization of the reservoir tank (not needed for
open tank). See Error! Reference source not found. on page Error! Bookmark
not defined..
Process Water Sidestream Filter*. Not available on chillers less pump and reservoir tank.
Includes a 50 micron filter, flow meter, ball valve for throttling water flow, and the necessary
piping to provide constant filtering of the process water at about one gallon per minute (1
gpm/3.8lpm).
General Fault Indicator Audible/Visual Alarm*. Includes a 100 dB audible alarm horn/
visual alarm strobe and silence button with provisions for customer wiring indication