repairing refrigerant leaks, replacing refrigerant components such as filter drier, pressure switch, metering device, coil, accumulator, or reversing valve.
Synthetic Roof Precautionary Procedure
1.Cover extended roof working area with an impermeable polyethylene (plastic) drip cloth or tarp. Cover an approximate 10x10 ft (3x3 m) area.
2.Cover area in front of the unit service panel with a terry cloth shop towel to absorb lubricant spills and prevent
3.Place terry cloth shop towel inside unit immediately under component(s) to be serviced and prevent lubricant
4.Perform required service.
5.Remove and dispose of any oil contaminated material per local codes.
Liquid Line Filter Drier
The biflow filter drier is specifically designed to operate with Puron. Use only
Puron (R-410A) Refrigerant Charging
Refer to unit information plate and charging chart. Some
Step 13 — System Information
Loss of Charge Switch
The loss of charge switch is a protective device wired into control circuit (low voltage). It shuts off the compressor if abnormally low pressures are present in the refrigeration circuit.
NOTE: Because these switches are attached to refrigeration system under pressure, it is not advisable to remove this device for troubleshooting unless you are reasonably certain that a problem exists. If switch must be removed, remove and recover all system charge so that pressure gauges read 0 psi. Never open system without breaking vacuum with dry nitrogen.
Check Defrost Thermostat
The defrost thermostat signals heat pump that conditions are right for defrost or that conditions have changed to terminate defrost. It is a thermally actuated switch clamped to outdoor coil to sense its temperature. Normal temperature range is closed at 32_ 3_F (0
1.7_C) and open at 65_ 5_F (18 2.8_C).
NOTE: The defrost thermostat is usually located on the lowest liquid leaving circuit of the left condenser coil.
FEEDER TUBE
STUB TUBE
DEFROST
THERMOSTAT
C99029
Fig. 21 - Defrost Thermostat
TROUBLESHOOTING
Refer to the Cooling and Heating Troubleshooting Chart (Table 9) for troubleshooting information.
START-UP CHECKLIST
Use the
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