Operation - Trane CVRC-M-1D Manual

Operation - Chiller Control System
Safety and operating controls are housed in the FastPak™ control panel,
the starter panel (optional) and the purge control panel (optional). The
FastPak control consists of a modular design partitioned by major function
or group of functions. All modules communicate with each other through
the IPC circuit. The modules and major components within each of these
control groups are described below. All wiring to the modules are to plug-
gable terminal blocks. Unit mounted temperature sensors, pressure trans-
ducers and functional switches provide analog and binary inputs to the
various modules.
a. Chiller Module
The Chiller module is the Master-of-the-Chiller, communicating commands
to other modules and collecting data/status/diagnostic information from
other modules over the IPC. The Chiller module performs the leaving
chilled water temperature and limit control algorithms arbitrating capacity
against any operating limit the chiller may find itself working against. The
chiller module contains nonvolatile memory for valid setpoints and retain-
ing them on any power loss. Inputs and outputs are chilled water system
level I/O including evaporator and condenser water temperatures, evapora-
tor and condenser water pump relays, programmable status and alarm re-
lays, external auto-stop, emergency stop, oil differential pressure switch, oil
temperature, optional condenser refrigerant pressure transducer, vent line
valve operation, and oil tank heater and pump operation. Connection
points for the Chiller module (1U1) are shown in the wiring diagrams at the
end of this manual.
b. Scorpio Module
The Scorpio module drives the Inlet Guide Vane Actuator (stepper or pulse)
and serves as an input/output expander. These inputs and outputs include
motor winding temperatures, bearing temperatures, discharge temperature,
saturated evaporator refrigerant temperature, optional oil differential pres-
sure transducer, safety string and IGV operation. Connection points for the
Scorpio module (1U3) are shown in the wiring diagrams at the end of this
manual.
c. Starter Module
The optional Starter module provides control of the starter when starting,
running and stopping the motor. The starter module provides protection to
both the motor and the compressor starter in the form of starting and run-
ning overload, phase reversal, phase loss, phase unbalance, momentary
power loss and compressor surge. Typical wiring connections to the
Starter module (2U1) are shown in the wiring diagrams at the end of this
manual.
d. Purge Module
The optional purge module is located in the purge control panel and pro-
vides all the inputs and outputs to control the purge, optimizing both purge
and chiller efficiency. Connection points for the Purge module (3U1) are
shown in the wiring diagrams at the end of this manual.
20 CVRC-M-1D