Repairing and maintaining air conditioners within proper intervals is a good way to increase their efficiency and longevity. However, in case the problem is major it is better to contact a professional as inexperienced handling might make the condition of you aircon worse or might even prove hazardous to your own self. Keeping that in mind, you would need a few regular tools to do the repairing works. Other than an assortment of screwdriver and a pliers, you might need a few extra tools like a multimeter and items based on the work that needs to be done in you compressor.
1. Before you do anything, the power to the system needs to be cut. Under no circumstances you are to work with the power still on. In case of difficulty in finding the source that powers the single unit in question, cut power of the general electricity providing unit of the vicinity (the house) if need be.
2. First thing you need to know is where the compressor is. The compressor along with the thermostat control, fans and the motor is placed between the coils covering the inner walls of the outer shell.
3. Now, with the help of the proper screwdriver, open the cover of the compressor. You would also need to open the electrical panel of the condensing unit. Sometimes the compressor’s cover is mounted by a fan that needs to be unscrewed and rotated sideways before you can proceed further. The fans are usually connected with long cables so there is no need to take them of entirely.
4. Now check the capacitors located behind the control panel of the system. They are usually of circular shape if not oval. Capacitors store electricity even after you disconnect the unit from its port so they need to be discharged before doing anything else. The manual that came along with the A/C shows how you can discharge them. Once they have been discharged, check their lids. In case you find them leaking or seem a bit swollen you need to replace them with the exact same model. Again, consult the manual to find the capacitor model name and type.
5. Sometimes when the A/C does not work properly, it is not because of a faulty compressor but for a damaged thermostat. To check if your thermostat is working properly, you would need to use the multimeter. A VOM (Volt-Ohm meter) would do. Before clamping the multimeter’s tester probes to the thermostat’s terminals, the meter needs to be set on RX1 scale. Now, once you have clipped the probes set the dial for controlling temperature to coldest. If the meter’s pointer shows zero, the thermostat is not faulty. However, in case the reading is higher than zero you need to replace the thermostat. Again, check the manual to find the model name of the item. Be careful while handling thermostats. There are sensitive bulbs connected to it to sense the temperature of the surrounding area. They need to remain undamaged and placed in the proper places before you took the thermostat off for checking.
6. Next, you need to check the wire terminals of the compressor. The terminal is usually covered so you might need to use a slotted or flathead screwdriver to pry the cover open. Once that has been done, check the connector-terminal condition. If they seem burnt or even loose, they need to be replaced with new connectors. Once the checking has been done, replace the cover properly. Dust is the worst enemy of electrical terminals.
7. Now you move on to the compressor. First you need to put your multimeter to Amp mode. Next, find the LRA (Lock Rotor Amps) and RLA (Rated Load Amps) ratings of the condenser from its ID label. LRA and RLA give the condenser’s maximum amperage (start-up) and equipment run amperage respectively.
8. There is a black wire coming out of the compressor’s COM (common) terminal. Find it and clamp the tester probes of the multimeter over it. Now, check VOM’s readout once you have turned the circuit breaker of the condenser on. It should be near-about the labeled LRA rating. The rating should drop and match the labeled RLA once the maximum speed is reached.
9. Now, once you turn the circuit breaker off the readout should not exceed the LRA rating. If it does, find the run-capacitor terminal of the compressor and place a hard start capacitor. If the LRA reading still exceeds the standard, the compressor needs to be replaced. In case of abnormal (higher or lower) RLA readout, check for high or low refrigerant level. If all these fail, you might have no other choice than to get a new compressor.