Trane CGAD020, Installation Operation & Maintenance

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CGAD-SVN02C-EN 25
!
WARNING!
In order to prevent accidents or
injuries from electric shocks, turn off
and lock in place all the electric
disconnects.
adding refrigerant.
RECLAIMINGREFRIGERANTFOR
SERVICE
The CGAD units 020, 025, and 030 have
only one circuit. The CGAD units 040,
045, and 050 have two circuits.
a. If the equipment is operating, turn the
A1 switch to the OFF position and
allow the compressors to reclaim the
gas normally. If the equipment is off,
do step B.
b. Turn off the power disconnect and
adjust the RCM leaving water setpoint
low enough to ensure that it calls for
cooling when the equipment turns on.
c. Install a jumper on terminals 117 and
118 of the low-pressure regulator of
circuit 1 (or on terminals 217 and 218
of circuit 2).
d. Turn on the power disconnect and
circuit breakers DJ3, DJ4, DJ5, DJ6.
e. Turn the Chiller switch to the ON
position. The lead compressor will
start up after the other. Allow both
circuits to operate for a period of at
least 5 minutes.
Carefully observe the suction
pressure of each circuit. The suction
pressure of any of the circuits could
drop below 10 psig during this period
of time. Immediately remove the
jumper or turn off the disconnect. If
this occurs, there is a malfunctioning
in the circuit. This problem should be
detected previously. If the unit
operates normally, continue on to step
F.
f. Manually close the service valve of the
liquid line in order to do the
reclaiming.
g. Carefully observe the suction
pressure manometer. When the
pressure drops to 10 psig, remove the
jumper from terminals 117-118 (or
217-218 in circuit 2).
It should also stop by the low-
pressure limit regulator. The com-
pressor should stop and in the sight
glass of the RCM should show bPA/
bPB, low pressure of refrigerant in
circuit A or B. Warning: do not operate
the scroll compressor in vacuum.
These compressors pull internally a
low vacuum if the suction side is
closed or restricted. This can cause
the aluminum rotor to bend, open the
circuit breaker, turn off the high
temperature thermostat, or burn the
fuses.
h. Manually close (seat) the discharge
service valve for this circuit.
i. Do the reclaiming from the other
circuit. Manually close the service
valve of the liquid line.
j. Carefully observe the suction pres-
sure manometer. When the pressure
drops to 10 psig, remove the jumper
from low-pressure switch 117-118
(Circuit 1) or 217-218 (Circuit 2).
CAUTION: The low-pressure limit
regulator should never be jumped.
The compressor should stop and in
the sight glass of the RCM should
show bPA/bPB, low pressure of
refrigerant in circuit A or B.
k. Close (seat) the discharge service
valve for this circuit.
l. Once the two circuits with the refriger-
ant are reclaimed, open and lock all
the disconnects. Keep the circuit
breakers open (OFF), which will keep
an accidental operation from happen-
ing while the circuit is without gas.
Operational
Procedures