Controls
Standard Features
Standard Features
Field Connection
The fi eld-connected elements are involved in physically turning the chiller on or off. This involves ensuring that the chiller is not in an emergency or external stop condition, starting the pumps, and verifying that fl ow has been established. The optional, factory-supplied fl ow switch or a customer- supplied differential-pressure switch can be used to prove fl ow.
Heat Exchanger Control
Fundamental internal variables that are necessary to control the chiller are gathered and acted upon by the heat exchanger control function.
Motor Control and Compressor Protection
This includes all functions that start, run, and stop the motor. The starter module provides the interface and control of Y-delta, across-the-line, primary reactor, autotransformer, and solid-state starters. The motor control also provides protection to both the motor and the compressor.
Phase Voltage Sensors – 3 phase
Includes factory-installed potential/current transformers in the starter for monitoring and displaying phase voltage and provides over/undervoltage protection. Tracer AdaptiViewTM control, Tracer TU and Tracer Summit display the following:
•Compressor phase amperage (a-b, b-c, c-a)
•Kilowatts
•Power factor (uncorrected)
•Compressor-phase voltage (a-b, b-c, c-a)
•Kilowatt-hours
Chilled-Water Reset
Chilled-water reset reduces energy consumption during periods of the year when heating loads are high and cooling loads are reduced. It is based on return chilled-water temperature. Resetting the chilled-water temperature reduces the amount of work that the compressor must do by increasing the evaporator refrigerant pressure. This increased evaporator pressure reduces the pressure differential the compressor must generate while in the heat recovery mode. Chilled-water reset is also used in combination with the hot-water control. By resetting the chilled-water temperature upward, the compressor can generate a higher condenser pressure, resulting in higher leaving hot- water temperatures.
