Sterlco GC Series Central Chiller - Manual (Page 14)

GC Series Central Chillers Chapter 2: Functional Description 14 of 79
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 module and shuts down the pump 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 install a switch or dry contact interlock
connected in series with the terminal points listed on the electrical schematic. Refer to the
electrical schematic supplied in the control enclosure. Once the wiring is complete the
controller will need to be reconfigured in the supervisor settings.
2-5 Optional Features
Options marked with “*” indicate options that can be factory installed or retrofitted in the
field.
General Fault Indicator Audible/Visual Alarm*. This end user can select the 85 dB (@ 2
ft/0.6 m) audible alarm; a 108,000 peak candle power, 80 flash/min. yellow warning light; or
a 108,000 peak candle power, 80 flash/min. red fault light. All three can be selected to
provide complete indication of the alarms. The alarm signals anytime that an issue is
recognized during the operation of the chiller.
Shell-and-tube evaporator. This option replaces the standard stainless steel brazed plate
and can be used when the process fluid cannot be kept clean. It also allows for more
serviceability by allowing a qualified refrigeration technician to plug one or multiple tubes
should they fail.
Compressor sound blanket.* The sound blanket can be added to reduce the sound pressure
levels of the compressor.
Electronic modulating hot gas bypass capacity control valve. Designed to trim the load of
one compressor and will modulate to meet the desired leaving fluid setpoint via a PID
algorithm.
Fluid differential pressure switch.* This differential pressure switch option can be added
to either the evaporator or a water cooled condenser. It measures the change in pressure
across the heat exchanger and will signal an alarm when the change is too high. The setting
of the switch is customer adjustable.
Evaporator flow meter.* This option provides the ability to display the actual flow rate
through the evaporator.
Pressure transducer input.* An analog pressure transducer may be added to the chilled
water in and/or chilled water out to measure the pressure of the process fluid through the
evaporator. These values will be added to the display.
Thermistor input.* A negative temperature coefficient (NTC) thermistor may be added to
measure the temperature of the fluid entering and/or leaving the entire system, and/or the
condenser out temperature.
NOTE: Up to (2) of the sensors listed above (evaporator flow meter, pressure
transducer input, and thermistor input) can be added per chiller module.