Refrigerator Troubleshooting Diagram

Domestic Refrigerator Components and Operations

with 4 comments

Capillary restrictor

Domestic refrigerators and freezers do not employ a mechanical device as a refrigerant flow control. Instead a capillary restrictor meters refrigerant liquid to the evaporator and maintains a pressure differential whilst the compressor is operating.

Basically the capillary restrictor is a small tube. The refrigerant flow rate is determined by the length of the tubing and the internal diameter of the bore. Refrigerant will continue to flow through the capillary when the compressor stops until the pressures in the system (high side and low side) equalize.

The capillary is normally located after the filter drier; it is sometimes formed into a tight coil around the suction line. Figure 56 shows a typical domestic refrigerator arrangement. It will be noted that the capillary actually passes through the inside of the suction line to the evaporator and thereby provides a heat exchange feature which improves compressor performance.

Domestic refrigerator details

Domestic refrigerator details


Suction line accumulators are employed to prevent frosting back along the suction line after off cycles. This is because the relatively small refrigerant charges in modern refrigerators and freezers are difficult to control accurately, and some overspill from the evaporator occurs when the compressor stops.

Accumulators are shown in Figures 52-55.

Freezer door heater and oil cooler

Figure 57 shows a freezer system diagram with door frame heater and oil pre-cooler.

Freezer door flame heating and oil cooling

Freezer door flame heating and oil cooling

Hot gas defrosting

Figure 58 shows the normal refrigeration and defrost cycles in an appliance using hot gas defrosting.

Hot gas defrosting

Hot gas defrosting

Solenoid flow control for refrigerator/freezer

Figure 59 shows the refrigeration system and Figure 60 the electrical circuit for solenoid flow control.

Refrigerator/freezer with solenoid flow control

Refrigerator/freezer with solenoid flow control

When the refrigerator thermostat is made and the freezer thermostat is open circuit, the relay is energized through contacts 1 and 3. The compressor operates but the solenoid is not energized, and the refrigerant flows through the refrigerator evaporator and the freezer evaporator.

Flow control circuit

Flow control circuit

When the freezer thermostat is made and the refrigerator thermostat is open circuit, the compressor operates and the solenoid is energized through contacts 1 and 2. The refrigerator evaporator is by-passed.

When the refrigerator thermostat makes whilst the compressor is operating, the relay is energized. This opens contacts 1 and 2, and refrigerant will again flow to the refrigerator evaporator as well as the freezer evaporator.

4 Responses to 'Domestic Refrigerator Components and Operations'

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  1. hi good evening i wnt to to combine refrigeration and water cooler arrangement of assably of diagram and plan efficiency of assebly. and compressor capacity how much by using of compressor. pl send me


    19 Aug 10 at 6:01 pm

  2. I have a New Dimensions Domestic Since 2001 I have to defrost it every 3 weeks. It starts to get warm Is that normal.We live in our Rv Can you help me? Debby Browmfield

    Debby Brownfield

    13 Nov 10 at 4:08 am

  3. I have a New Dimensions Domestic 9 years old I have to Defrost Every 3weeks the fridge gets warm. Is that normal. We live in our R.V. Debby Brownfield

    Debby Brownfield

    13 Nov 10 at 4:12 am

  4. hi,i want few line diagram of refrigerator please send me


    21 Sep 11 at 7:53 am

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