Trane Cold Generator CGWR Series User Manual

Electrical Wiring
CG-SVX038A-EN 29
CCAR Condenser Fan Staging or VFD
Control
The CCAR compressor chiller unit controller has the ability
to control fan staging, fan VFDs and damper control in
order to improve the stability of discharge pressure at
various ambient conditions.
Unit controller capability single circuit compressor chillers
(CCAR 20, and 30) have three dry contact relays to cycle
condenser fan motors to control discharge pressure, as
well as one 0 to 10 Vdc analog output to control a VFD or
fan damper. Dual circuit compressor chillers (CCAR 40, 50,
and 65) have six dry contact relays to cycle condenser fan
motors to control discharge pressure, as well as two 0 to
10 Vdc analog output to control a VFD or fan damper.
CCAR unit controller must control condenser ambient
control devices such as fan cycling and optional low
ambient dampers. As a result the interconnecting field
wiring must be done by others. For pairing CCAR
compressor chiller with CAUJ air cooled condenser, the
following field wiring is to be done by others.
• Fan cycling control
• One con
trol wire for each condenser fan plus a
common must be run between CCAR compressor
chiller and CAUJ condenser.
• Required fan control wiring for CCAR compressor
chillers matched with CAUJ condensers utilizing
fan control are covered by schematic, instructions,
and associated footnotes on Figure 21, p. 53 and
Figure 22, p. 54.
• Low Ambient Dampers (when applicable)
• One shielded pair for each condenser damper
assembly must be run between CCAR compressor
chiller and CAUJ air cooled condenser.
• Required damper control wiring for CCAR
compressor chillers matched with CAUJ
condensers utilizing low ambient control damper
assembly are covered by schematic, instructions
and associated footnotes on Figure 23, p. 55 and
Figure 24, p. 56.
CGWR Condenser Water Loss of Flow
Protection
The controller logic will sense a loss of flow through the
condenser. No flow switches are necessary with the
standard unit controller configuration.
CGWR Condenser Control
CGWR units have one dry contact relay to start a
condenser pump. These chillers also have one 0 to 10 Vdc
analog output to control a head pressure control valve.
Consult wiring diagram located inside the control box
door for connection point(s).
Equipment Grounds
Provide proper grounding at the connection point
provided in the unit control panel.
Unit Controller
Note: The unit controller section in this IOM contains only
a brief overview of the unit controller. Please
consult the Unit Controller Version 17 Manual Rev.
3.0 for Cold Generator™ Chillers (CG-SVX030*-EN)
which documents the function of the unit controller
including setpoint definitions, points lists and
much more.
The unit controller is a rugged microprocessor based
controller designed for the hostile environment of the
HVAC/R industry. It is designed to be the primary manager
of the CCAR/CGWR product.
The unit controller provides flexibility with setpoints and
control options that can be selected prior to
commissioning a system or when the unit is live and
functioning. Displays, pressures, temps, alarms and other
interfaces are accomplished in a clear and simple
language that informs the user as to the status of the
controller. Refer also to the wiring diagram attached to the
inside of the control panel door.
A password is required to access controller setpoints. Use
password code 2112 to access many of these features. A
factory code may be required to allow access to critical
areas, and can only be entered by a factory representative.
A RS-485 port is provided for communication with other
manufacturers’ systems. Additionally, a built-in RS-485 to
RS-232 converter allows communication over the RS-485
port via the RS-232 port. Other features include the
integration of BACnet
®
IP and MODBUS
®
into the unit
controller. An optional gateway card allows
NOTICE:
Unexpected Chiller Start!
Failure to follow instructions could cause the chiller to
start unexpectedly which could result in equipment or
property damage. An external source (EMS, time clock
or any other means) should not be allowed to bring on
a pump that would trigger the flow switch to start the
chiller. The flow switch is meant to act as a safety
switch and not a start/stop mechanism.
NOTICE:
Use Copper Conductors Only!
Failure to use copper conductors could result in
equipment damage as the equipment was not designed
or qualified to accept other types of conductors.

Trane Cold Generator CGWR Series Specifications

General

Brand	Trane
Model	Cold Generator CGWR Series
Category	Chiller
Language	English