Honeywell DH65DG115 User Guide - Page 12

Installation Guide Technical Description TrueDRY DH65 uses a refrigeration system similar to an air conditioner to remove heat and moisture from incoming air and add heat to the air that is discharged. Hot, high-pressure refrigerant gas is routed from the compressor to the condenser coil. The refrigerant is cooled and condensed by giving up its heat to the air that is about to be discharged from the unit. The refrigerant liquid then passes through a strainer and capillary tubing which causes the refrigerant pressure and temperature to drop. It next enters the evaporator coil where it absorbs heat from the incoming air and evaporates. The evaporator operates in a flooded condition, which means that all the evaporator tubes contain liquid refrigerant during normal operation. A flooded evaporator should maintain nearly constant pressure and temperature across the entire coil, from inlet to outlet. STRAINER/FILTER DRIER CONDENSER EVAPORATOR COMPRESSOR CAPILLARY TUBES ACCUMULATOR M27404 Troubleshooting CAUTION: Servicing the TrueDRY DH65 with its high pressure refrigerant system and high voltage circuitry presents a health hazard which could result in death, serious bodily injury, and/or property damage. Service should only be performed by a qualified service technician. Problem No dehumidification, neither fan nor compressor run with fan switch and ventilation timer OFF. No dehumidification, compressor does not run but fan runs when there is a call for dehumidification and the ventilation control is OFF. Fan runs when there is a call for dehumidification and the ventilation control is OFF, but the compressor cycles on and off too frequently. Recommended Troublshooting Steps 1. Unit unplugged or no power to outlet. 2. Humidity control set too high or defective. 3. Loose connection in internal or control wiring. 4. Defective Compressor relay. 5. Defective control transformer. 6. Low pressure control open. 7. Optional Condensate Pump Safety Switch open. 1. Defective compressor run capacitor. 2. Bad connection in compressor circuit. 3. Defective compressor overload. 4. Defective compressor. 5. Defrost thermostat open. 6. Optional Condensate Pump Safety Switch open. 1. Low ambient temperature and/or humidity causing unit to cycle through defrost mode. 2. Defective compressor overload. 3. Defective compressor. 4. Defrost thermostat defective. 5. Dirty air filter(s) or airflow restricted. 6. Low refrigerant charge, causing defrost control to cycle. 7. Bad connection in compressor circuit. Fan does not run with fan switch in either position. 69-2089EFS-08 10 69-2089EFS_D.indd 10 9/22/2008 10:02:41 AM