**New Science Air Conditioner: Compressor automatically shuts down after running for 10~15 seconds**
**Fault Phenomenon**: A New Science 1.5KW air conditioner starts the compressor, which runs for 10~15 seconds and then automatically shuts down. After about 2 minutes, it restarts on its own and runs for another 10~15 seconds before shutting down again. This process repeats continuously. However, during the repeated start-stop cycle of the compressor, the temperature remains normal.
**Fault Detection**: Based on the observed phenomenon, the first step was to inspect the temperature controller, overload protection device, and overheat protector. No fault sources were found in these areas. The focus of the inspection was then shifted to the compressor. Upon opening the compressor, the motor windings were found to be in good condition. A pressure test was then conducted by attaching a pressure gauge to the high-pressure pipe and starting the compressor. When the pressure rose from 0 to approximately 0.49 Mpa, the compressor automatically shut down. Power was disconnected, and upon restarting, the motor did not move. Attempting to manually rotate the rotor also failed. After the pressure dropped, the compressor was restarted, and the motor began running again. However, when the pressure reached 0.49 Mpa, the compressor stopped again, repeating the same phenomenon. This unit uses a reciprocating compressor. After disassembling the compression cylinder cover, it was discovered that the spring blade of the one-way valve between the compression cylinder and the high-pressure pipe had weakened due to prolonged use, resulting in an inability to close tightly. This caused incomplete reverse isolation between the high-pressure pipe and the compression cylinder. Therefore, when the motor was running, the pressure in the high-pressure pipe gradually increased, as did the pressure in the compression cylinder, increasing the load on the compression piston connected to the motor shaft. When the load reached a certain level, the motor overloaded and shut down protectively.
**Repair Measures**: After replacing the one-way valve blade, the fault was resolved.
**Beijing New Science Air Conditioner Repair Center, August 10, 2011.**