Motor testing often alludes to issues before visual inspection makes them apparent. Motor testing with a preventive maintenance program can test motors while they're operating in their normal environment under normal loads to confirm they're running at acceptable or optimum limits. Motor testing is often used in a preventive maintenance or reliability-centered maintenance program. These standards are constantly reviewed and improved when deemed necessary by the board. Motor testing is regulated by the Institute of Electrical and Electronics Engineers (IEEE) through standards such as IEEE 43 – Insulation Resistance and Polarization Index, IEEE 56 – Maintenance AC Hipot Test, IEEE 95 – DC Hipot Test, and IEEE 400-2001 – The Guide for Field Testing and Evaluation of the Insulation of Shielded Power Cable Systems. While each motor test applies to most alternating current (AC) or direct current (DC) motors, each testing method depends on the construction and application of the motor in question. Mechanical motor testing includes things like looking into the cracks of a motor's rotor and lamination sheet makeup.

Specific to electric motors, motor testing evaluates static parameters like insulation, wire damage and electrical current leakage, as well as more dynamic parameters such as distortion, temperature fluctuations and balance. The main objective of motor testing is to reveal hidden problems and prevent unnecessary failure.

Motor testing assesses the integrity of a motor through the use of computer-supported equipment or tools that monitor trends within the motor.

Electric motor winding