Trane R Series Installation Operation & Maintenance page 37

Control Power Supply
The unit is equipped with a control
power transformer; it is not necessary
to provide additional control power
voltage to the unit. All units are factory-
connected for appropriate
voltages except for the 400V/50Hz
units which need the control power
transformer (1T1) reconnected as noted
below.
NOTE: Important! As shipped, a normal
400 volt unit control power transformer
is wired on the 400 volt tap (H3).
Reconnect the appropriate transformer
wire lead 126A to the tap (H2) for
380V/50Hz power supply or lead 126A
to the tap H4 for the 415V/50 Hz power
supply. It is also necessary to adjust the
"unit voltage" setting using TechView
(Configuration-Custom Tab).
Heater Power Supply
Convenience Outlet (Packaged Units
Only)
The evaporator shell is insulated from
ambient air and protected from freezing
temperatures by two thermostatically-
controlled immersion heaters and two
strip heaters. Whenever the water
temperature drops to approximately
37°F (2.8°C), the thermostat energizes
the heaters. The heaters will provide
protection from ambient temperatures
down to -20°F (-29°C).
It is required to provide an independent
power source (115V
amp, 220V 50Hz-15 amp), with a
fused-disconnect. The
factory-wired back to the unit control
panel.
CAUTION Heat Tape!
Control panel main
does not check for loss of power
to the heat tape nor does it verify
thermostat operation. A qualified
technician must verify power to the
heat tape and confirm operation
of the heat tape thermostat to
avoid catastrophic damage to the
evaporator.
RTAC-SVX002A-EN
Installation Electrical
Interconnecting Wiring
Chilled Water Flow (Pump) Interlock
The Model RTAC Series R® chiller
requires a field-supplied control voltage
contact input through a flow proving
labeled
switch 5S1 and an auxiliary contact
5K1 AUX. Connect the proving switch
and auxiliary contact to 1TB5-8 and
1U11 J3-2. Refer to the field wiring for
details. The auxiliary contact can be
BAS signal, starter contactor auxiliary.
or any signal which indicates the pump
is running. A flow switch is still required
and cannot be omitted.
Chilled Water Pump Control
An evaporator water pump output relay
closes when the chiller is given a signal
to go into the Auto mode of operation
and
from any source. The contact is opened
to turn off the pump in the event of most
machine level diagnostics to prevent
the build up of pump heat.
CAUTION
Evaporator Damage!
IMPORTANT: ALL unit chilled water
pumps must be controlled by the
Trane CH530 to avoid catastrophic
damage to the evaporator due to
freezing. Refer to RLC-PRB012-EN.
The relay output from 1U10 is required
60Hz-20
to operate the Evaporator Water Pump
(EWP) contactor. Contacts should be
heaters are
compatible with 115/240 VAC control
circuit. The EWP relay operates in
different modes depending on CH530
or Tracer commands, if available, or
service pumpdown (See maintenance
processor
section). Normally, the EWP relay
follows the AUTO mode of the chiller.
Whenever the chiller has no diagnostics
and is in the AUTO mode, regardless
of where the auto command is coming
from, the normally open relay is
energized. When the chiller exits the
AUTO mode, the relay is timed open
for an adjustable (using TechView) 0
to 30 minutes. The non-AUTO modes
in which the pump is stopped, include
Reset (88), Stop (00), External Stop
(100), Remote Display Stop (600),
Stopped by Tracer (300), Low Ambient
Run Inhibit (200), and Ice Building
complete (101).
Regardless of whether
is allowed to control the pump on a
full-time basis, if the MP calls for a
pump to start and water does not
flow, the evaporator may be damaged
catastrophically. It is the responsibility
of the installing contractor and/or the
customer to ensure that a pump will
start when called upon by the chiller
controls.
the chiller
37