Trane RTXC XE Series Installation Operation & Maintenance page 29

ampacity)
Single/Dual
Point Power
Recommended
Wire Size mm
Evaporator
Recommended
Heater
Wire Size mm
Wiring
NOTICE - Control Fault!
To prevent control malfunctions, do not run low voltage wiring (<30V) in conduit with conductors carrying
more than 30 volts.
Starter panel
All controls components and motor starts are wired and functional tested in factory. The starter panel enclosure is
designed per environmental rating IP54, and be suitable for outdoor use. The starter panel includes the controls
for one or two compressors, and a disconnect switch (or a circuit breaker) with handle as the power supply
connecting point. The starter panel is divided into the power section for compressors and associated condensing
fans controls, and the control section of UC800 control system.
The power section includes the Wye-Delta starter for each compressor, and the condensing fans' on and off
control. The UC800 system acquires the compressor motor current of each phase by current transformers, to
avoid the damage of running under unbalanced current, under/over current, phase loss or phase reversal. The
UC800 system also monitors the line voltage by potential transformer, to avoid the motors are running under
abnormal voltage. A control power transformer is offered to provide the 110Vac and 24Vac power supply to the
unit control system.
The control section includes I/O modules, power supply modules, starter modules and the user interface.
Power Supply Wiring
All wiring must comply with local codes. Entrance for incoming power wiring is located on the lower right side of
the starter panel. The wiring is connect to the disconnect switch or optional circuit breaker.
Unit water pump control
NOTICE - Equipment damage!
Trane only allows the customer select either one of the offered schemes for chilled water pump control
and evaporator antifreeze protection. Fail to do so may result in equipment damage and the loss of
related guarantee rights without the authorization or approval from Trane.
Single unit chilled water pump control
For single unit, the UC800 system offers 2 relay contacts of chilled water pump control, total 2 control schemes
are provided. Scheme 1, when the chilled water pump is corresponding with specific unit and controlled by this
unit, the relay contact J2-4 and J2-6 of module 1A20 controls the chilled water pump running and stop, when the
unit receives the running command, this relay contact will close. In most cases of the unit fault diagnostics
appear, this contact will open to shut the chilled water pump, to avoid the pump overheat.
Scheme 2, when the chilled water pump is controlled by customer, the relay contact J2-1 and J2-3 of module
1A20 need to be connected to customer's chilled water pump control circuit, as part of the evaporator antifreeze
protection, or when entering the oil return protection, the contact needs to close to activate the pump.
Single Single Single
185 300 300
2
2
Single Single Dual
185/40
400 400 185/400
0
2.5
29
Dual Dual Dual
300/400 400/400
Dual
400/400