| Controls 10,15 Tons
Interface with Other Control Systems
Stand-Alone Unit
Figure 28-1 —
Stand-Alone Unit
Interface to stand-alone units is very
simple; only a remote auto-stop or chilled water flow interlock signal for scheduling is
required for unit operation. Signals from the chilled water pump contactor auxiliary or a
flow switch are wired to the chilled waterflow interlock. Signals from a time clock or
some other remote device are wired to the external auto-stop input. Unit controls do not
provide an output to turn pumps on and off.
Required Features
- External Auto/Stop (Standard) - or -
- Chilled Waterflow Interlock (Standard)
Trane Integrated Comfort™ System
Interface
Figure 28-2 — Tracer®
ICS System Interface Schematic
A single twisted pair of wires tied
directly between the CGA unit and a Tracer ® system provides control, monitoring and
diagnostic capabilities. Control functions include auto/stop, compressor operation lockout
for kw demand limiting. In addition, the Tracer system can provide sequencing control for
two or three CGA units on the same chilled water loop. Pump sequencing control can be
provided from the Tracer system also. Sequencing of two CGA’s can be accomplished
with the DDC Chiller Sequencer.
Required Features
- Unit Temperature Controller (Standard)
- ICS Interface Panel
External Trane Devices Required
- Tracer 100 System - or -Tracer L System
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