CAUTION! To prevent compressor
damage, do not operate the unit
until all refrigerant and oil line
service valves are opened.
5 Verify that the chilled water pump
runs for at least one minute after
the chiller is commanded to stop
(for normal chilled water systems).
6 Press the AUTO key. If the chiller
control calls for cooling and all
safety interlocks are closed, the
unit will start. The compressor(s)
will load and unload in response to
the leaving chilled water
temperature.
Once the system has been operating
for approximately 30 minutes and
has become stabilized, complete the
remaining start-up procedures, as
follows:
1 Check the evaporator refrigerant
pressure and the condenser
refrigerant pressure under
Refrigerant Report on the CLD
Module. The pressures are
referenced to sea level (1013 mbar
-14.7 psia).
2 Measure the system discharge
superheat.
3 Measure the system subcooling.
4 A shortage of refrigerant is
indicated if operating pressures
are low and subcooling is also low.
If the operating pressures, sight
glass, superheat and subcooling
readings indicate a refrigerant
shortage, gas-charge refrigerant
into each circuit, as required. With
the unit running, add refrigerant
vapor by connecting the charging
line to the suction charging service
valve port until operating
conditions become normal.
CAUTION! If both suction and
discharge pressures are low but
subcooling is normal, a problem
other than refrigerant shortage
exists. Do not add refrigerant, as this
may result in overcharging the
circuit. Use only refrigerants
specified on the unit nameplate
(HFC 134a) and Trane Oil 00048.
Failure to do so may cause
compressor damage and improper
unit operation.
Note: On Free-Cooling units, in
Compressor mode, the procedure
will remain the same. In Free
Cooling mode, only point 1 needs to
be checked, as the compressors are
not running. To release more cooling
capacity and reduce pressure drop,
Trane recommends using 50%
nominal water flow while in Free
Cooling mode.
General
If the pre-start checkout, as
discussed above, has been
completed, the unit is ready to start.
1 Press the STOP key on the CLD
module.
2 As necessary, adjust the setpoint
values in the UCM-CLD « Operator
Settings » menu.
3 Close the fused-disconnect switch
for the chilled water pump.
Energize the pump(s) to start water
circulation.
4 Check the service valves on the
discharge line, oil line and liquid
line for each circuit. These valves
must be open (backseated) before
starting the compressors.
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RTAD-SVX01F-E4
Unit Start-up Procedures