Sterling 882.93092.00 specifications Optional Features, High Pressure Cutout, Flow Switch

Caution! Energize the crankcase heater for at least 24 hours before initial startup to drive dissolved refrigerant from the compressor oil. Failure to do so will damage the compressor.

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)

There are two pressure transducers in the refrigeration piping – one on the suction line before the compressor and one on the discharge line after the compressor. Within the program there are four settings that warn and fault based on these two pressure transducers. The low suction warning is set for 110 psig (758 kPa), and the compressor will fault at 100 psig (689 kPa).

The low discharge warning is set for 200 psig (1,379 kPa), and the compressor will fault at 180 psig (1,241 kPa). To prevent nuisance tripping there are delays built in to the program.

Note: Call a refrigeration service technician to analyze the problem to prevent recurring low pressure faults.

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 1 and 23, 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..

GP Series Portable Chillers Chapter 2: Functional Description 10 of 73