How Do You Load Test An Electric Motor

You may find that when it runs ungrounded that the casing becomes live at up to supply voltage.

How do you load test an electric motor.

Knowledge of the basics together with powerful new test equipment vastly simplifies the job. If there is any reading on any of these then the motor is bad do not use it. It s possible the problem could be the wring or the power source and not the electric motor. Thus a 10 horsepower hp motor has an acceptable load range of 5 to 10 hp.

Maximum efficiency is usually near 75 of rated load. So when a motor fails to operate it may not be obvious what the problem is. However if you re motor isn t working use a multimeter to test it before deciding to replace it. Sometimes the trouble lies within the power supply including branch circuit conductors or motor controller.

Deviations from rated fla could signify problems with the motor under test. Peak efficiency is at 7 5 hp. Do the following with the motor disconnected. Look at the label on the electric motor to determine the voltage it needs to operate.

Reasons to determine motor loading most electric motors are designed to run at 50 to 100 of rated load. Keep the multi meter set for 30 000 ohms and touch one test lead to one terminal and the other to another terminal. Even though you may have to do a bit of work by splitting the coupling this test will really help you to find out if the motor is bad or good since it is not usual for a bad motor to run off load. When an electric motor fails to start runs intermittently runs hot or continually trips its overcurrent device there my be a variety of causes.

Additionally along with these tests you will also have to test your voltage contacts contact check terminal check etc. Check c to e s to e r to e. Electric motors have had a reputation for being a mix of science and magic. When an electric motor is broken one suspect is the fiel coild of the motor stator.

Minimum test value for a good electric motor is at least 1mω running amps test with the motor running check the full load amps fla with a suitable meter or preferably a clamp on meter and compare with the motor name plate fla. Another possibility is that the driven load is jammed binding or mismatched. With a multimeter set to low ohms usually 200 test between each winding terminal and the metal casing of the motor. A motor s efficiency tends to decrease dramatically below about 50 load.