Data Aire gForce Ultra, Installation, Operation And Maintenance Manual

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Step 4: Add refrigerant weights from step 1 through 3 together and multiply by .80 to
get the starting charge.
Example: model GUAX-125XX (37.5 + 57 lbs. + 55) *.80 = 119.6 lbs.
2. Next connect the refrigerant tank to the refrigerant manifold gauge set and make sure the
manifold gauge set is properly purged
3. Then from a vacuum, slowly open the high side liquid line valve on the refrigerant manifold
gauge to feed liquid refrigerant through the high side.
4. Add the amount of refrigerant weight per tables, slowly open the high side liquid line valve on
the refrigerant manifold gauge to feed liquid refrigerant through the high side.
At this point there will be approximately 70-80% of the total charge in the system. It is likely that more
refrigerant will be required to complete the charging procedure. Close the valve on the refrigerant
manifold gauge set.
WARNING: Before starting a compressor, the crankcase heater should be
energized for a minimum of 12 hours to reduce the possibility of liquid slug-
ging on start-up. Failure to energize the crankcase heater could result in
compressor damage. If the system is charged from a vacuum, the preheat-
ing of the compressor is not necessary.
NOTE: A quick and easy way to run the fans and compressor is by using
the manual slide switches provided by the Manual Override Module (Exclu-
sively for floor mounted units. Ceiling mounted units are not equipped
with Manual Override Module!)
All automatic control is disabled but safety
switches will remain functional.
Before turning the system on to finish charging the circuit make sure you check for voltage phasing.
For more information on this refer to section 5.3.
Manually start the system by first sliding the “Blower” switch to ON position on the manual override
board. Allow time for all fans to start and come up to a constant airflow before starting the constant
speed compressor. Then manually start the constant speed compressor by sliding the “Cool 2” switch
to the ON position on the manual override board to turn on the constant speed compressor. Allow the
system to stabilize to room temperature. Bubbles in the sight glass are not unusual at this point.
Finishing charging by slowly opening the valve on the refrigerant manifold set to meter liquid refriger
-
ant into the low side of the system.
If the receiver head pressure is below the required pressure (350 PSIG (2413 kPa) for R-410A), block
part of the condenser coil surface until the pressure rises. During extremely cold weather all the con -
denser fans may have to be de-energized to maintain head pressure.