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START-UP AND MAINTENANCE
8 - 4
Close the Ball Valve immediately downstream of
the Receiver and connect the proper refrigerant to
its Access Port. Slowly open the liquid valve on
the refrigerant tank and charge the Receivers to
60% on the liquid gauge. Disconnect refrigerant
tank and open the ball valve. Liquid level should
decrease as refrigerant is drawn out into system
field piping.
CAUTION: The remaining charge must be
added only as vapor through the suction
header.
Note: With non-azeotropic refrigerants, it is best
to charge the entire contents of the cylinder to
prevent fractionalization of the refrigerant when
charging vapor.
Charge the system to approximately 30% of the
receiver on the liquid gauge. Turn on compressor
number one to speed up charging. Its suction
pressure should remain below 20 psig for low
temperature and below 45 psig for medium
temperature units. If necessary, turn on more
compressors. Monitor the oil levels carefully.
At the first sign of trouble or unusual compressor
operation shut off the system.
After 30% charge is achieved, check oil levels.
Bring on each compressor one at a time.
Check:
Suction and discharge pressure
Oil Pressure
Voltage differential and balance
Ampere draw and balance.
Allow the full rack to operate until it stabilizes. If
the Receiver charge drops below 15% add more
vapor until a 15% level is obtained. Watch oil
levels, receiver liquid level and possible flood
back from evaporator.
HUSSM ANN CORPORATION • BRIDGETON, M O 63044-2483 • Printed in USA
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Shut off all compressors and recheck oil levels in
each compressor and the Turba-shed. Leak
testing, evacuation and initial charging are now
completed.
Compressor Motor Rotation
To check compressor rotation, use the following
procedure:
1. Install gauges on suction and discharge
headers. Be aware of Satellite and Split-
Suction Scroll Plus units when making
hook-up. A momentary compressor run
should cause a drop in suction header and
a rise in discharge header pressure.
2. With main disconnect OFF, switch OFF all
breakers in the control panel except the
control circuit breaker.
3. Turn ON main disconnect.
4. Look for the red light on the single phase
protector. If it is not lit, turn OFF the main
disconnect. All Scroll Plus 3-Phase wiring is
connected: L 1 to T 1 , L 2 to T 2 , and L 3 to T 3 .
Have the field connections corrected so the
phase protector indicates phase alignment.
(The red light is lit.)
5. Turn ON main disconnect.
6. Using the compressor controller, force all
compressors ON.
7. Momentarily turn ON compressor breaker #1
and verify correct pumping direction. Check
all compressors before switching any wires. If
all compressors are rotating backwards,
change two Legs at the field side of the main
disconnect. For individual compressors,
change the Legs on the load side of the
compressor contactor.
8. Using the compressor controller, remove all
forced conditions.
September 1, 1997
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