Brief Analysis on Overload Protection Technology of Air Conditioning Compressor

The air conditioner compressor is easily affected by the voltage and the working conditions of the refrigeration system. In a bad environment, the compressor is easy to burn out. As the most expensive component of an air conditioner, the protection technology of the compressor has become an important subject that must be paid attention to in the field of air conditioner technology.

In the existing compressor protection technology, the current transformer or temperature sensor detection technology is used most. The former uses the current transformer to sense the current of the main circuit of the compressor, and obtains the compressor current through current detection. When the current exceeds When setting the value, the main circuit is disconnected to protect the compressor through software control, and the current transformer can be installed in the indoor unit or outdoor unit; the temperature sensor detection technology is to install a temperature sensor on the surface of the compressor to detect the temperature of the compressor The temperature is used to protect the compressor. Since the compressor coil is inside, the temperature rise between its surface and the outside is very different, and the temperature measurement error is relatively large. In the case of instantaneous overcurrent, the protection effect is not ideal. The above two technologies need to be controlled by a single-chip microcomputer, and one or two connection lines need to be added between the indoor unit and the outdoor unit, and the manufacturing cost is relatively high.

It has been found from relevant experiments that compressor burnout often occurs when there is a lack of refrigerant and under harsh operating conditions. The temperature of the compressor coil is related to the intake pressure and the amount of refrigerant. This article mainly discusses that under the condition that the software and hardware of the indoor unit of the commonly used air conditioner remain unchanged, the pressure switch is used as the pressure detection device, and an electric control board for detection is added in the idle space of the outdoor unit to detect the pressure of the compressor. Realize the overload protection of the compressor. With this solution, there is no need to change the original circuit of the air conditioner, and it has strong versatility, and can be applied to different types of air conditioners, and the indoor unit does not need to be changed.