Figure 1: The refrigerator compressor.

The compressor of a refrigerator plays a key role in the cooling effect of the refrigerator, as well as the refrigeration cycle. One side of the compressor pulls the gaseous refrigerant to the other side by suction and then pushes it out. If you need to repair the refrigerator or locate the low side of the compressor, a simple visual inspection will be all you need.

Basic Principle of Refrigerator Compressor

The compressor of the refrigerator is located at the back of the unit. In terms of technology, it is both a motor and a pump. Usually, a refrigerator compressor looks like a small, dark cylinder. One of its sides is connected to a condenser, which is a copper tube bent into a coil or zigzag shape.

The compressor is an important part of the exhaust and refrigeration system on the equipment, working with the condenser, evaporator and expansion valve or capillary. All of these components work together to help the refrigerator turn a liquid refrigerant into a gas and then back to liquid again.

Figure 2: Parker Sporlan Expansion Valve EBSPE-6

Through this process, the refrigerator is able to keep the temperature low and expel dangerous chemicals from the equipment.

Working Principle of Refrigerator Suction Tube

Essentially, a compressor is a pump that draws in gaseous refrigerant stored in the evaporator, which is leftover from the previous cooling cycle of the equipment. And that's why it's considered as a refrigerator suction line -- it sucks in the cold gaseous refrigerant.

The compressor, driven by a motor, heats the gas before delivering it to the condenser. Then when the temperature drops, the gas will change into a liquid. Finally, the expansion valve reduces the temperature of the refrigerant and the pressure acting on the refrigerant.

This process allows about half of the refrigerant to evaporate. The evaporator converts the remaining refrigerant into a gas, which the compressor uses to restart the refrigeration cycle.

Figure 3: Refrigerator structure.

Locate the Low Side of Refrigerator Compressor

After you have a basic knowledge of how the refrigeration process works on the refrigerator, you can roughly determine the low side of the compressor.

The refrigerant is drawn into the device through the evaporator, from where it is discharged to the condenser. After determining the condenser’s position, you can follow the path.

The valve between the condenser and the compressor is the output valve. Once you know where the output valve is, you can find the other valve, the suction valve, on the compressor. It is installed on the evaporator.

Figure 4: The evaporator.

Although you can also identify the low side of the compressor by finding the evaporator, it may be easier to locate the condenser, which is large in volume and looks like a coiled or twisted copper pipe.

Safety Precautions

You should make sure that you have unplugged the device before trying to locate the low side of the refrigerator compressor. In addition, you are not supposed to attempt to move the refrigerator by yourself.

The equipment is heavy and may cause personal injury. What’s worse, it can tip over and lead to accidents. Before starting to look for the low side of the compressor inside the fridge, you must guarantee there are no children or pets nearby.

Related Info