Electrical testing services
Motor Testing
Comprehensive electrical testing for AC and DC motors — from acceptance testing of new installations to condition assessment of in-service motors in industrial and utility applications.
Protect Your Most Critical Rotating Assets
Electric motors are the workhorses of industrial facilities — driving pumps, compressors, fans, conveyors, and process equipment that keep operations running. Motor failures are among the most common causes of unplanned downtime, and most failures are preceded by detectable electrical degradation. Periodic motor testing identifies insulation weakness, winding faults, and connection problems before they cause a failure.
J. Wesley Services Group performs motor testing on new installations and in-service motors in accordance with NETA standards and IEEE 43 guidelines. Our testing programs give maintenance teams the data they need to make informed decisions about motor condition, repair, and replacement.
Motor Tests We Perform
Insulation Resistance Testing
Megger testing of motor winding insulation to ground, measuring resistance in megohms. Results are evaluated against IEEE 43 acceptance criteria and corrected for temperature. Trending insulation resistance over time is one of the most effective indicators of winding condition.
Polarization Index (PI)
A ratio of the 10-minute to 1-minute insulation resistance reading that indicates the condition of winding insulation. A low PI value suggests contamination, moisture, or deteriorated insulation that may not be apparent from a single resistance reading alone.
Winding Resistance Testing
Measures the DC resistance of each motor winding phase using a precision micro-ohmmeter. Unbalanced winding resistance between phases indicates connection problems, shorted turns, or damaged windings that will cause unbalanced currents and overheating.
Surge (Impulse) Testing
Applies high-voltage impulses to motor windings to detect turn-to-turn insulation faults that are not detectable by standard megger testing. Surge testing is particularly effective for identifying early-stage winding faults before they develop into ground faults.
Power Factor / Dissipation Factor Testing
Measures the dielectric loss of motor winding insulation, providing a sensitive indicator of insulation aging, contamination, and moisture. Power factor testing is especially useful for large, high-value motors where detailed condition assessment is warranted.
Vibration Analysis (Visual and Electrical)
Assessment of motor condition through electrical signature analysis and coordination with mechanical vibration data. Electrical testing complements mechanical inspection to provide a complete picture of motor health.
Motor Types We Test
- AC induction motors (low and medium voltage)
- DC motors and generators
- Synchronous motors and generators
- Submersible pump motors
- Large industrial process motors (100 HP and above)
- Critical service motors in petrochemical and utility applications