5
Figure 2: Refrigeration system of Phoenix
4.3 Troubleshooting
No dehumidification. Neither blower or compressor
run. Power switch does not light when ON.
1.
Unit unplugged or no power to outlet.
2.
Power switch defective (Sec. 2.6).
3.
Loose connection in internal wiring (Fig. 3).
No dehumidification. Neither blower or compressor
run. Power switch ON & lit.
1.
Low pressure control open (Sec. 2.11).
2.
Power switch defective (Sec. 2.6).
3.
Loose connection in internal wiring (Fig. 3).
Some dehumidification, blower runs continuously
but compressor only runs sporadically.
1.
Unit is in defrost cycle (Sec. 2.10 & 4.7).
2.
Defrost thermostat defective or loose
(Sec. 2.10 & 4.7).
3.
Loose connection in compressor circuit
(see Fig. 3).
4.
Defective compressor overload (Sec. 4.6A).
5.
Defective compressor (Sec. 4.6).
6.
Defective relay (Sec. 4.9).
7.
Defective time delay (Sec. 4.10).
No dehumidification. Blower runs but compressor
does not. Pump fail light not lit.
1.
Bad connection in compressor circuit (Fig. 3).
2.
Defective compressor capacitor (Sec. 4.6A).
3.
Defective compressor overload (Sec. 4.6A).
4.
Defective compressor (Sec. 4.6).
5.
Defective relay (Sec. 4.9).
6.
Defective time delay (Sec. 4.10).
No dehumidification. Pump Fail Light lit. Blower
runs but not compressor.
1.
Bad connection in pump circuit (Fig. 3).
2.
Pump float switch or safety switch defective
(Sec. 4.8).
3.
Pump motor defective (Sec. 4.8).
Blower does not run. Compressor runs briefly but
cycles on & off.
1.
Loose connection in blower circuit (Fig. 3).
2.
Obstruction prevents impeller rotation.
3.
Defective blower (Sec. 4.5).
Unit removes some water but not as much as
expected.
1.
Air temperature and/or humidity have dropped.
2.
Humidity meter and/or thermometer used are out
of calibration.
3.
Unit has entered defrost cycle (Sec. 2.10 & 4.7).
4.
Air filter dirty (Sec. 3.1).
5.Defrost timer incorrectly set for conditions (Sec.
2.10 & 4.7).
6.Defective defrost thermostat (Sec. 4.7)
7.
Low refrigerant charge (Sec. 4.4).
8.
Air leak such as loose cover.
9.
Defective compressor (Sec. 4.6).
10. Restrictive exhaust ducting (Sec. 2.5)
Unit runs but does not pump water.
1.
Hose kinked or plugged.
2.
Pump check valve plugged (Sec. 4.8).
3.
Bad connection in pump circuit (Fig. 3).
4.
Hose disconnected internally.
Unit pumps water automatically but not when
purge switch is pushed.
1.
Bad connection in purge switch circuit
(Fig. 3).
2.
Defective purge switch (Sec. 2.7).
Evaporator coil frosted continuously, low
dehumidifying capacity.
1.
Defrost thermostat loose or defective
(Sec. 2.10 & 4.7).
2.
Defrost timer incorrectly set or defective
(Sec. 2.10 & 4.7).
2.
Low refrigerant charge (Sec. 4.4).
3.
Dirty air filter or air flow restricted. (Sec. 3.1).
Compressor runs with power switch OFF.
1.
Defective relay (Sec. 4.10).
2.
Defective power switch (Sec. 2.6)
4.4 Refrigerant Charging
If the refrigerant charge is lost, a new charge must be
accurately weighed in. If any of the old charge is left in
the system, it must be removed before weighing in the
new charge. Refer to the unit nameplate for the correct
charge weight and refrigerant type.
