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NOTE:
Charging to a full liquid line sight glass should never be the sole
means of determining the correct refrigerant charge. Other parameters
such as superheat, suction pressure, head pressure, sub-cooling and
ambient temperature are also important. A system charged to a clear
sight glass is often overcharged.
When charging is complete, close the valve on the refrigerant manifold set and close the service
valve on the refrigerant tank. Stop the compressor by pressing and holding the ESC key to put
the unit in OFFbyKEY mode. Then reset the require return air temperature setpoint.
5.7.2. Flooded System Charging (Systems with Low Ambient Receiver Package)
WARNING:
The fixed speed compressor (2
nd
stage) must be charged
before charging the variable speed compressor (1
st
stage) in an Ultra dual
circuit system.
NOTE:
Prior to refrigerant charging, a system vacuum and moisture
removal procedure must have been carried out. Refer to
Evacuation and Dehydration Procedure
for a triple evacuation prior to
charging the system.
NOTE:
Improper charging procedure could cause compressor damage
in several ways: excessive Low/High Pressure differences, liquid slugging
or vacuum operation. The below system refrigerant charge procedure is
strongly recommended to reduce these risks.
WARNING:
The compressor power must be OFF and the safeties ON to
prevented from starting inadvertently/automatically.
WARNING:
Before starting a compressor, the crankcase heater should
be energized for a minimum of 12 hours to reduce the possibility of liquid
slugging on start-up. Failure to energize the crankcase heater could
result in compressor damage. If the system is charged from a vacuum,
the preheating of the compressor is not necessary.
NOTE:
Charging to a full liquid line sight glass should never be the sole
means of determining the correct refrigerant charge. Other parameters
such as superheat, suction pressure, head pressure, sub-cooling and
ambient temperature are also important. A system charged to a clear sight
glass is often overcharged.