Refrigerator Troubleshooting Diagram

Archive for the ‘Evaporator Section’ tag

Condensing Unit And Evaporator Section

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There are times when everything appears to be operating according to all specifications, yet, insufficient cooling is the

Heat strips energizing with cooling-Check the heat relay in the air handler and see if there is 24 volts being applied to the holding coil.

The resistive heaters would counteract the cooling effect. Sometimes the contacts of a heat relay weld in the closed position, causing this. If 24 volts are found at the relay when the thermostat mode is in cooling, you must check the system circuitry. Disconnecting for the summer is alright; however, you will have to isolate the problem sooner or later. The source should be found in the evaporator section. It is either receiving its voltage from the thermostat or the defrost device in the condensing unit, if it is a heat pump. Sub-bases are sometimes the blame. They distort on an uneven wall surface causing them to crack or short circuit.

Written by sam

December 24th, 2010 at 9:11 am

Evaporator Section Blowing Hot Air

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Check condensing unit to see if it is operating. Place one hand on the liquid line and the other on suction line. If the condenser fan is operational and there isn’t any difference in the temperature of the two lines, the compressor is not operating. If the fan motor is not operating, check for line voltage and low voltage in the control panel. You must establish if the problem is in line voltage or low voltage. If line voltage is present, and there is no low voltage, nothing will operate.

No line voltage—           Check fuses for the supply voltage to the condensing unit.

No low voltage—               If present through the thermostat, a wire from the thermostat to the condensing unit is open.

tests can be made over a period of time. In the above case, the pressure recorder hooked to the high side of the system. The amperage recorder should be hooked to the condenser fan motor power supply. Each time the compressor cycles on, the pressure is recorded on a chart similar to those used in the medical profession. Everytime the compressor cycles so should the condenser fan motor. The defective motor will stop operating and thus the amperage will either fall to zero or climb to locked rotor and fall. This would be followed by the high pressure side of the system starting to elevate. This is truly the only way to solve a situation such as this.

Written by sam

December 24th, 2010 at 8:57 am