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PROBLEM
UNIT OPERATES TOO LONG OR CONTINUOUSLY
1. Low refrigerant charge.
2. Control contacts fused.
3. Air in system.
4. Partially plugged expansion valve or filter drier.
SYSTEM IS NOISY
1. Piping vibration.
2. Compressor noisy.
COMPRESSOR LOSES OIL
1. Leak in system.
2. Crankcase heaters not energized during shutdown.
3. Improper interconnecting piping design.
FROSTED SUCTION LINE
1. Expansion valve admitting excess refrigerant.
HOT LIQUID LINE
1. Shortage of refrigerant due to leak.
2. Expansion valve opens too wide.
FROSTED LIQUID LINE
1. Restricted filter drier.
2. Liquid line solenoid valve partially closed.
NOTE(S):
a. On 569J***T/U systems, Outdoor Fans 2 and 4 will be off in cooling mode below 55°F ± 1.5°F outdoor temperature.
APPENDIX A — AIR CONDITIONER AND HEAT PUMP WITH PURON
•
Puron (R-410A) refrigerant operates at 50 percent to
70 percent higher pressures than R-22. Be sure that servic-
ing equipment and replacement components are designed
to operate with Puron refrigerant.
•
Puron refrigerant cylinders are rose colored.
•
Recovery cylinder service pressure rating must be
400 psig, DOT 4BA400 or DOT BW400.
•
Puron systems should be charged with liquid refrigerant.
Use a commercial type metering device in the manifold
hose when charging into suction line with compressor
operating.
•
Manifold sets should be 700 psig high side and 180 psig
low side with 550 psig low-side retard.
•
Use hoses with 700 psig service pressure rating.
•
Leak detectors should be designed to detect HFC refrigerant.
•
Puron, as with other HFCs, is only compatible with POE
oils.
•
Vacuum pumps will not remove moisture from oil.
•
Use only factory specified liquid-line filter driers with
rated working pressures greater than 600 psig.
•
Do not install a suction-line filter drier in liquid-line.
•
POE oils absorb moisture rapidly. Do not expose oil to
atmosphere.
Table 22 — Troubleshooting (cont)
1. Add refrigerant.
2. Replace control.
3. Purge and evacuate system.
4. Clean or replace.
1. Support piping as required.
2. Replace compressor if bearings are worn.
1. Repair leak.
2. Check wiring and relays. Check heater and replace if defective.
3. Check piping for oil return. Replace if necessary.
1. Adjust expansion valve.
1. Repair leak and recharge.
2. Adjust expansion valve.
1. Remove restriction or replace.
2. Replace valve.
•
POE oils may cause damage to certain plastics and roofing
materials.
•
Wrap all filter driers and service valves with wet cloth
when brazing.
•
A factory approved, liquid-line filter drier is required on
every unit.
•
Do not use an R-22 TXV.
•
If indoor unit is equipped with a TXV, it must be changed
to a Puron TXV.
•
Never open system to atmosphere while it is under a vacuum.
•
When system must be opened for service, recover refriger-
ant, break vacuum with dry nitrogen before opening
system.
•
Always replace filter drier after opening system for
service.
•
Do not vent Puron refrigerant into the atmosphere.
•
Do not use capillary tube coils.
•
Observe all warnings, cautions, and bold text.
•
All Puron heat pumps must have indoor TXV.
•
Do not leave Puron suction line driers in place for more
than 72 hours.
39
SOLUTION
®
– QUICK REFERENCE GUIDE
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