Protective valve for compressor

The utility model relates to a protective valve for a compressor, belonging to a component of refrigeration equipment. The utility model can add the functions of shutdown and instant starting for compressors of refrigerators and freezers. The protective valve for a compressor is composed of the combination of a one-way valve and a pressure release electromagnetic valve, and then the protective valve is matched with a weighted starting relay for a compressor; after the pressure release electromagnetic valve is connected with a temperature controller and a compressor overload protector, the actions of the pressure release electromagnetic valve can be completely synchronous to the compressor. When the compressor is shut down, the pressure release electromagnetic valve can be opened to release the high air pressure of the compressor, and simultaneously, the one-way valve can cut down the high air pressure of an evaporator, so that the high and the low air pressures of compressor can be balanced, and the compressor can be instantly started. The compressor can not be burnt out due to start failure which is caused by unstable power supply under various conditions, so that the performance of refrigerators and freezers can be increased, and, the compressor can be protected.