Unit Shutdown Procedures; Temporary Shutdown And Restart; Extended Shutdown Procedure - Trane RTAA-130 Installation, Operation And Maintenance Manual

Unit Shutdown
Procedures
Temporary Shutdown
and Restart
To shut the unit down for a short time,
use the following procedure:
1. Move the Chiller Switch to STOP/
RESET. The compressors will
continue to operate and, after
unloading for 20 seconds, will stop
when the compressor contactors de-
energize. The condenser fans will be
de-energized at this time.
2. The unit disconnect switch and unit
mounted disconnect (if installed)
should remain closed to keep the
compressor sump heaters energized.
3. Maintain power to keep the
evaporator and Domestic Water
Heater heat tape(s) energized.
4. Stop the chilled water circulation by
turning off the chilled water pump.
To restart the unit after a temporary
shutdown, restart the chilled water
pump and move the Chiller Switch to
either of the AUTO positions. The unit
will start normally, provided the
following conditions exist:
1. The UCM must receive a call for
cooling and the differential- to-start
must be above the setpoint.
2. All system operating interlocks and
safety circuits must be satisfied.
Extended Shutdown
Procedure
The following procedure is to be
followed if the system is to be taken out
of service for an extended period of
time, e.g. seasonal shutdown:
1. Test the condenser and high-side
piping for refrigerant leakage.
2. Open the electrical disconnect
switches for the chilled water pump.
Lock the switch in the "OPEN"
position.
Caution: Lock the chilled water
pump disconnect open to prevent
pump damage.
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3. Close all chilled water supply valves.
Drain the chilled water from the
evaporator. If the unit will be
exposed to freezing ambient
conditions, flush the evaporator with
an antifreeze solution and energize
the evaporator heat tape.
Caution: To prevent damage to the
evaporator by freezing, flush the
evaporator with an antifreeze
solution and energize the
evaporator heat tape.
4. Drain the Domestic Water Heater and
any exposed system piping to
prevent the possibility of freeze-up.
Use the pressure tap on the water
outlet to force compressed air
through the water coils of the unit
and assure that no water blocks any
of the tubes. Be certain that the drain
valve on the water inlet is open
before applying compressed air to
the water coils. Energize the
Domestic Water Heater heat tape.
Caution: To prevent damage to the
Domestic Water Heater by
freezing, blow out water from coils
and energize the Domestic Water
Heater heat tape.
5. Open the unit main electrical
disconnect and unit-mounted
disconnect (if installed) and lock on
the "OPEN" position. If optional
control power transformer is not
installed, open and lock the 115 V
disconnect.
Caution: Lock the disconnects on
the "OPEN" position to prevent
accidental start-up and damage to
the system when it has been setup
for extended shutdown.
6. At least every three months
(quarterly), check the pressure in the
unit to verify that the refrigerant
charge is intact.
RTAA-IOM-3