Trane CGWF - Manual (Page 9)

9 CG-PRC012-EN
Controls
Easy Interface to A Generic Building
Management System
Controlling the scroll CGWF chiller with
building management systems is state-
of-the-art, yet simple with either the
LonTalk Communications Interface for
Chillers (LCI-C) or Generic Building
Management System Hardwire Points.
Simple Interface with Other Control
Systems
CH530 controls afford simple interface
with other control systems, such as time
clocks, building automation systems,
and ice storage systems. This means
you have the flexibility to meet job
requirements while not having to learn a
complicated control system. This setup
has the same standard features as a
stand-alone water chiller, with the
possibility of having additional optional
features.
What are LonTalk, Echelon, and
LonMark?
LonTalk is a communications protocol
developed by the Echelon Corporation.
The LonMark association develops
control profiles using the LonTalk
communication protocol. LonTalk is a
unit level communications protocol,
unlike BACNet used at the system level.
LonTalk Communications
Interface for Chillers (LCI-C)
LonTalk Communications Interface for
Chillers (LCI-C) provides a generic
automation system with the LonMark
chiller profile inputs/outputs. The inputs/
outputs include both mandatory and
optional network variables. Note:
LonMark network variable names are in
parentheses when different from chiller
naming convention.
Chiller Inputs:
• Chiller Enable/Disable
• Chilled Liquid Setpoint (Cool Setpoint)
• Compressor Inhibit
• Chiller Mode (Ice Making)
Chiller Enable/Disable
Allows for chiller to be started or
stopped depending on if certain
operating conditions are met.
Chilled Water Setpoint
Allows for the external setting
independent of the front panel setpoint
to adjust the leaving water temperature
setpoint.
Compressor Inhibit
Locks out the second compressor on
each circuit, reducing the kW draw.
Ice Making
Provides interface with ice making
control systems. Please refer to page 11
for more information.
Chiller Outputs:
• On/Off
• Active Setpoint
• Average Percent RLA
• Compressor Inhibit
• Compressor Starts
• Compressor Run Times
• Leaving Chilled Water Temperature
• Entering Chilled Water Temperature
• Evaporator Refrigerant Temperature
• Evaporator Refrigerant Pressure
• Evaporator Water Pump Request &
Flow Status
• Leaving Condenser Water Temperature
• Entering Condenser Water Temperature
• Condenser Refrigerant Temperature
• Condenser Refrigerant Pressure
• Condenser Water Pump Request &
Flow Status
• Outdoor Air Temperature (CCAF)
• Alarm Descriptor
• Chiller Status
Active Setpoint
Indicates the current value of the leaving
water temperature setpoint
Average Percent RLA
Provides the current capacity level via %
RLA
Compressor Starts and Run Times
Provides the number of starts and run
time for each compressor
Alarm Descriptor
Provides alarm messages based on pre-
determined criteria
Chiller Status
Indicates the running modes and states
of the chiller, i.e. Running in alarm mode,
chiller enabled, chiller being locally
controlled, etc…
Generic Building Management
System Hardwire Points
GBAS may be achieved via hardware
input/output as well. The input/outputs
are as follows:
Chiller Hardwire Inputs Include:
• Chiller Enable/Disable
• Circuit Enable/Disable
• External Chilled Water Setpoint
• Compressor Inhibit
• Ice Making Enable
Programmable Relays and Alarms
The unit provides seven output options,
of which four can be chosen.
a) Compressor running indication
b) Maximum capacity
c) Chiller limit mode
d) Warning informational diagnostic
indication
e) Alarm latching shutdown diagnostic
indication
f) Alarm nonlatching shutdown
diagnostic indication
g) Alarm latching or nonlatching
shutdown diagnostic indication