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13HPD SERIES
Figure 13. Typical Unit Wiring Diagram
IMPORTANT
Crankcase heater (if applicable) should be energized 24
hours before unit start−up to prevent compressor dam-
age as a result of slugging.
Servicing Outdoor Unit Delivered Void of
Nitrogen Charge
If the outdoor unit is void of factory nitrogen charge, clean
the system using the procedure described below.
1. Use nitrogen to repressurize system and check for
leaks.
2. Evacuate the system using evacuating procedure
provided in this instruction.
3. Use nitrogen to break the vacuum and install a new
filter drier in the system.
4. Evacuate the system again using evacuating
procedure provided in this instruction.
5. Weigh in refrigerant using procedure outlined under
Unit Start−Up and Weigh−In Charging.
6. Monitor the system to determine the amount of
moisture remaining in the oil. It may be necessary to
replace the filter drier several times to achieve the
required dryness level.
If system dryness is not
verified, the compressor will fail in the future.
Unit Start−Up and Weigh−In Charging
1. Check that fan rotates freely.
2. Inspect all factory− and field−installed wiring for loose
connections.
3. After evacuation of the outdoor unit, line set, and
indoor unit are complete, close the manifold gauge set
valves. Disconnect vacuum pump from center hose of
gauge set.
4. Connect the center hose of the gauge set to a cylinder
of HCFC−22 and purge the hose. Then, place the
cylinder upside down on a scale (see figure 14).
5. Open the high side manifold gauge valve and weigh in
liquid refrigerant. Refer to unit nameplate to determine
correct weigh−in charge (see figure 15)
6. Close manifold gauge valves.