Controls – Trane Centrifugal Water Chillers CVGF User Manual

Page 16

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 AdaptiView

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.

Standard Features

CTV-PRC001-E4

Controls