How to Measure the Quality of a Compressor?
2 Answers
Methods to measure the quality of a compressor: 1. Resistance measurement method: 1. First, remove the rear cover of the refrigerator and locate the compressor. 2. Then, use a flathead screwdriver to pry off the black electrical cover on the left side of the compressor, exposing the protector and starter. Next, remove the two components with the screwdriver to reveal the compressor's three sealed terminals. 3. Now, you can use the probes of a multimeter to measure the resistance by touching the terminals. The normal resistance should be less than 1 ohm. 2. Current measurement method: 1. Similarly, remove the rear cover of the refrigerator, locate the compressor, and remove the black electrical box cover. 2. Then, find the part where the power cord connects to the compressor. There will be three wires: red, blue, and yellow-green. The red and blue wires are the live and neutral wires, respectively, and the yellow-green wire is the ground. 3. Finally, set the multimeter to ammeter mode and measure the current of the red and blue wires using the probes. Normally, the current should be between 0.4-0.8 amps. If the current exceeds this range or is zero, it indicates that the compressor has issues or is faulty.
To check the compressor's condition, I usually start the engine and turn on the AC, setting it to the lowest temperature and highest fan speed. Listen to the compressor's operation sound: normally, there should only be a slight humming noise. If continuous abnormal sounds like clicking or grinding noises are heard, there may be mechanical wear. Then, inspect the compressor housing and surrounding pipes for any oil stains; excessive oil stains indicate aging seals or leaks. Next, connect an AC pressure gauge to the high and low-pressure service ports: the high-pressure side should maintain between 150-300 kPa, and the low-pressure side around 25-45 kPa. Abnormal or unstable pressure suggests the compressor isn't cooling or there's a blockage. Observe if the pulley rotates normally when the AC is on; if not, check the electrical connections or clutch failure. Through these steps, combined with testing the cooling effect by checking if the air from the vents quickly turns cold, you can assess the overall condition. Regular checks on the compressor's health can prevent unexpected AC system failures and save on repair costs.
