How to Test Single-Phase Motor Windings
In this episode, Keith walks us through how to test and check motor windings on a single phase motor. If you suspect your motor is starting to fail, it could be a symptom of broken windings. Keith will also show us how to check the insulation resistance of a motor.
00:00 Introduction
00:59 Why test motor windings and insulation?
01:13 How to Test Three Phase Motor Windings
01:25 How to Test Windings on a Single Phase Motor
01:52 Motor Winding Resistance Test
02:24 How to Check Insulation Resistance of a Motor
02:48 When to Test Motor Windings With a Megger
Our step by step guide to test your single phase motor windings:
✅ Disconnect the motor power supply.
✅ Next, you’ll test your capacitors. Check out other video for the step by step guide to test the capacitor: • How to Replace a Motor Capacitor
✅ Remove the end bell off and do a visual inspection of the motor windings. You’re looking for burns, melting, or breaks in the motor windings. If you do see burns, your motor’s likely been overloaded and will need to be repaired or replaced.
✅ Next, we’ll check the resistance of your motor windings to make sure the start and run are not shorted together and they are not grounded.
✅ Make sure your multimeter is set to measure in OHMS and place the meter across the isolated winding leads.
✅ If your insulation is good, your multimeter will ready OL. If the windings are shorted, the multimeter will read 0.
✅ Use your multimeter to see if there is continuity or low resistance between any of the motor leads to the terminal and the housing or chassis. Repeat with all the leads. There should be high resistance between all the leads and the motor chassis. If any of these tests indicate a low resistance, your insulation may be damaged.
✅ If your resistance is low but not zero, you could also test with a megohmmeter to get a more accurate reading. Instead of a true short circuit, you may be dealing with a direct short, insulation breakdown, or dielectric breakdown. The megohmmeter (sometimes called a 'megger') applies a high voltage, so you should be cautious when using this device.
Need help replacing a single phase or three phase motor? Contact our team now: https://www.emotorsdirect.ca/contact-us