Unit installation

7
STANDARD CONTROL & SAFETY DEVICES AND OTHER ACCESSORIES
The chillers are provided with the following items as a standard practice:
Microprocessor Controller: This controller monitors analog and digital inputs to achieve precise control & safety
functions of the unit.
Compressor In-Built Protection Device: Protect the compressor by monitoring:
a. Motor winding temperature in case of overload.
b. Discharge gas temperature in case of overheating.
c. Phase reversal for direction of rotation.
Starters: The starter is operated by the control circuit and provides power to the compressor motors. These devices
are rated to handle safely both RLA and LRA of motors.
Under/Over Voltage and Phase Protection: Protects against low/over incoming voltages as well as single phasing,
phase reversal and phase imbalance by de-energizing the control circuit. It is an automatic reset device, but it can be
setup for manual reset.
Crankcase Heaters: Each compressor has crankcase heater. The compressor crankcase heater is always on when
the compressors are de-energized. This protects the system against refrigerant migration, oil dilution and potential
compressor failure.
High Pressure Switch: This switch provides an additional safety protection in the case of microprocessor failure to
cut-out on high pressure alarm.
Unit On-Off Switch: On-Off switch is provided for manually switching the unit control circuit.
Indicator Lights: LED lights indicate power ON to the units, MENU adjustment and FAULT indications due to trip on
safety devices.
Electronic Expansion Valves: Electronic expansion valve is used to regulate the refrigerant flow to the water cooler
and maintain a constant superheat and load optimization.
Replaceable Core Type Filter Drier: Refrigerant circuits are kept free of harmful moisture, sludge, acids and oil
contaminating particles by the filter drier.
Control Circuit Transformer: For units rated with 460V-3Ph-60Hz power supply factory mounted and wired control
circuit transformer is furnished eliminating the need for running a separate 220-volt power supply to the unit control
circuit.
Sight Glass: Moisture indicating sight glass installed in the liquid line. An easy-to-read color indicator shows moisture
contents and provides a mean for checking the system refrigerant charge.
Liquid Line Solenoid Valves: Closes when the compressor is off to prevent any liquid refrigerant from accumulating
in the water cooler during the off cycle.
OPTIONAL FEATURES
The chillers can be provided with the following items based on specific client/project requirements:
Hot Gas Bypass System: Hot gas bypass is provided on the lead circuit to permit operation of the system down to
50% of its unloaded capacity. Under low ambient condition, it controls temperature by eliminating the need to cycle the
compressor on and off, ensuring narrow temperature swing and lengthen the life span of the compressor.
Water Flow Switch: Paddle type field adjustable flow switch for water cooler circuits. Interlock into unit safety circuits
so that the unit will remain off until water flow is determined.
Unit Mount Spring Isolators: This housed spring assemblies with a neoprene friction pad on the bottom dampen the
vibration transmission.