How to check brushless motor?

If you use brushless motors in the industry, you must ensure that they are always in perfect working condition. Although it is a good idea to schedule regular maintenance of all electronic equipment, if you can test the brushless motor yourself, you can save some service costs.

If your brushless motor is not spinning, you need to find the problem. If you want to test a brushless motor, here are some tips.

This passage is going to talk about the followings of brushless motor:

(1)   How to test whether the brushless motor is short-circuited?

(2)   How to perform dry test on brushless motors?

(3)   What should I do after the brushless motor test?

(1)   How to test whether the brushless motor is short-circuited?

Brushless motors work by using electromagnets instead of brushes to rotate the motor. The magnet is installed on the bell of the motor and pushes and pulls the motor as needed.

Electromagnets can also be used to generate electricity. Rotating the motor by hand generates power. Many modern generators use the same process to generate electricity. If any of the two wires are shorted together, you will encounter resistance when trying to rotate the motor by hand. If all the wires are separated, there should be no problem with rotation when pushing the motor by hand.

If you have separated all the wires and the motor still cannot rotate, you can assume an internal short circuit.

(2)   How to perform dry test on brushless motors?

If your motor is spinning, but has recently overheated or suffered sustained damage, you may need to dry test it to see if there are any problems. You can follow the steps below to dry test the brushless motor.

first step

Disconnect the motor from the electronic speed controller (ESC), then use a variable-speed battery-operated electric drill to wind the motor and keep the fixed part isolated from the three wires. Run at full speed for a few minutes. If the motor makes strange noises or the internal temperature of the motor rises, it indicates that the windings are short-circuited or the magnets are loosened and hit the stator in the motor.

Second step

Mark the three motor wires, making sure to continue to isolate them from each other, 1, 2, and 3. Now connect the voltmeter to the AC range and connect two of the wires to terminals 1 and 2. Pay attention to the AC voltage again. Repeat this process for terminals 2 and 3 and 1 and 3.

If all three readings are different, there is a problem with your motor cable.

third step

Check whether there is a short circuit between the stator and the winding. Look for any connections between the windings and the motor stator laminations. You need to find bare metal on the stator to connect to one of the meters and the other on the meter winding. If it cannot be found, create one by puncturing the coating of the steel stack.

If the meter does not show an open circuit, the motor may have fired.

fourth step

If your motor passes all these tests, it should be fine. However, before putting it back into operation, you may need to check the no-load current of the motor and compare it with the specifications provided by the manufacturer. This will enable you to identify shorted turns or shorted windings in the motor.

If the turn is short-circuited, the motor cannot be used. It will generate a very high temperature, which will cause the motor to malfunction and possibly damage the ESC.

(3)   What should I do after the brushless motor test?

Naturally, if your brushless motor passes all the tests and appears to be operating normally, you can put it back into service, although you should still be vigilant and check it during regular maintenance. If the brushless motor fails any tests, it may have to be repaired or replaced. Contact us now for more services.