How To Check A Small Electric Motor

The meter should not show an open or a short when a winding leg is measured.

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. Consult the motor schematic or a diagram of the motor s windings and use the meter to measure the resistance of the windings. 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. This is the case for the motors on deep well submersible pumps where the capacitor and starter relay are located away from the submersed motor.

They generally operate on low voltage electricity 6 to 24 volts and are powered by batteries or a transformer that reduces 110 volts to the required low voltage. Test the winding for shorted or open circuits. The bearings allow the shaft or rotor assembly to turn freely and smoothly in the frame. Check c to e s to e r to e.

Load to motor may be excessive or unbalanced. Small electric motors operate a wide variety of electrical devices such as remote control models children s railroad sets and computers. In the ohmmeter mode connect the meter to the plug and monitor the resistance as you wiggle the cord where it enters the enclosure. For defective winding replace the motor.

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. Check the power supply to make sure voltage is accurate. Small universal motors as for portable electric drills may contain extensive circuitry including a switch and brushes. Begin to check the bearings of the motor.

Each winding leg should have some small resistance reading.