How To Check A Small Electric Motor

The bearings allow the shaft or rotor assembly to turn freely and smoothly in the frame.

How to check a small electric motor.

Bearings are located at both ends of the motor which are sometimes called bell housings or end bells. Check c to e s to e r to e. Consult the motor schematic or a diagram of the motor s windings and use the meter to measure the resistance of the windings. Load to motor may be excessive or unbalanced.

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. Check the motor load and inspect the drive belt tension to ensure it s not too tight. Each winding leg should have some small resistance reading. The amps may also be high.

Small universal motors as for portable electric drills may contain extensive circuitry including a switch and brushes. Test the winding for shorted or open circuits. Check the starter control box for capacitor start motors where this function is separate from the motor itself and no malfunctions are evident with the motor body itself. Begin to check the bearings of the motor.

Check the power supply to make sure voltage is accurate. For defective winding replace the motor. Small electric motors operate a wide variety of electrical devices such as remote control models children s railroad sets and computers. Many electric motor failures are caused by bearing failures.

In the ohmmeter mode connect the meter to the plug and monitor the resistance as you wiggle the cord where it enters the enclosure.