Most motors, whether AC motors or DC motors, will fail due to time, which may not be electrical in nature. Since there are few moving parts, motors without brushes and commutators (such as AC (alternating current) induction motors) have the longest service life. AC and DC brush motors (such as those used in vacuum cleaners and power tools) generate high power in a short period of time and stop working when worn brushes and commutators are issued. To check any type of faulty motor, follow logical steps. If you want to learn more, you can read the comprehensive guide below.
This passage is going to talk about the followings of ac motor:
(1) Check bearings and shafts of an ac motor
(2) Check the ac motor windings with a multimeter
(3) Ensure that the ac motor fan is in good condition and firm
Check bearings and shafts of an ac motor
Motor bearings are one of the most vulnerable components. Bearings are subject to regular wear and tear, so you need to replace them over time. You must check the bearings regularly, because if you continue to use the motor with worn bearings, it will damage the mechanism and reduce the efficiency of the motor.
The bearings are easy to check. All you need to do is rotate the bearings to make sure they rotate smoothly and freely. Another way to check the bearing is by pushing and pulling the shaft to which the bearing is connected. The bearing should rotate smoothly and the shaft should be able to move smoothly. That is, if you hear scratching or feel any friction, you may need to replace the bearing. If the friction is small, the bearing may only need lubrication.
Check the ac motor windings with a multimeter
Not surprisingly, the windings of a motor are critical to its machinery. You should check the wear of the winding regularly, but more importantly, you need to analyze its resistance. First, you will need a multimeter to test the windings. First, set the multimeter to read ohms, and then test the wires and terminals of the motor. You should test the "short to ground" in the winding circuit and open the winding or shorts.
To test whether the motor is shorted to ground, you need to set the multimeter to ohms and disconnect the power to the motor. Then check each wire, looking for infinite readings. Or, if the reading is 0, it may be a cable problem. To determine whether the cables are damaged, each cable should be tested separately and make sure that no wires are touching. Testing separately allows you to find the cable causing the problem. On the other hand, if each cable provides unlimited readings, it may be a motor problem, so you should hire a professional repair service.
Ensure that the ac motor fan is in good condition and firm
Too many people forget to check and maintain the fan of the ac motor. The fan is very important to the performance of the motor, because it keeps the motor cool and can run for a long time. You might suspect that the fan is easily clogged with dust and debris, which reduces airflow and keeps heat in. Although the outside of the fan looks relatively clean, dust and debris may accumulate elsewhere, which can slow the fan. When removing the fan cover for cleaning, also test the fan and make sure it spins freely. In addition, the fan should be fixed on the motor. Otherwise, the fan will not operate normally, and the motor will overheat, and eventually it will definitely be damaged.