Two Minute Tips  

Beginner’s Guide To Motor Testing

Mark Koch | Technical Support Manager, ALL-TEST Pro, LLC

Why Is Motor Testing Important?

Motor testing improves machinery and plant availability by eliminating unscheduled machinery shutdowns and failures. Maximized revenue is achieved when these critical machines are operating, so testing motors must be a top priority for a successful company.

With the proper instruments, effective and complete motor testing takes just moments to perform.

1. Not All Motor Faults Are Obvious

Physical senses of sight and sound provide a valuable indication of the proper operation of motors, but usually, by the time these senses are aware a fault is present, severe and expensive damage has already occurred. The correct instruments can locate loose connections, degrading insulation or other faults that may arise from changing temperatures, multiple start-ups, or excessive vibration.

2. Identify Motor Issues as They Develop

Insulation, windings, stators and other motor components experience wear and tear over time. Knowing the condition of the motor’s insulation is critical for extended trouble-free operation.

3. Motor Testing Promotes Safety Initiatives

Motors that overheat are a danger to employees, plants or facilities. The correct instruments help pinpoint where a repair is necessary before an issue occurs.

Common Motor Testing Procedures for Beginners

  • Low-voltage motor testing: Locate faults between conductors in the motor windings.
  • Insulation resistance testing:  MCA™ testing solutions fully test the condition of motor groundwall insulation as well the ability to detect faults in the stators, rotors, cables and all insulation systems.

How to Test a DC Motor Safely

Beginners should follow all basic electrical safety tips when motor testing. For those new to the motor testing process, ALL-TEST Pro provides step-by-step guide outlined below you can reference when using MCA solutions for deenergized motors:

  1. Disconnect wired connections running between the motor and DC battery.
  2. Look for uninsulated portions of the conductor to perform the test.
  3. Ensure the DC voltage to the motor is disconnected from all parts of the equipment.
  4. Using a “confirmed” working voltage tester, verify all power has been removed from the motor leads that are going to be tested.
  5. Fasten test lead clips to motor listed motor leads.
  6. Select the winding test from the testing menu on the testing instrument.
  7. Connect the proper instrument test lead to the correct motor lead before performing tests.
  8. Follow the on-screen instructions to test the entire motor coils.
  9. Always refer to your motor’s manufacturing manual to be certain of connections.
Notify of

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Inline Feedbacks
View all comments

About the Author

Mark Koch Technical Support Manager, ALL-TEST Pro, LLC

Mark Koch is a member of the Technical Support team at ALL-TEST Pro, LLC (ATP), where he has provided professional support worldwide for users of ATP equipment since 2014. He has 17 years of electrical and reliability maintenance experience. In 2001, he started his career as a construction electrician. During this time, he worked his way up from shop floor apprentice to a foreman in charge of starting and completing remodel and new construction projects. In 2010, he began working at the Metropolitan Sewer District (MSD) of Greater Cincinnati, Ohio, USA, where he learned electrical maintenance best practice and helped implement a predictive maintenance program (PdM). During his service at MSD, his team was the recipient of both the Uptime Magazine’s Best Emerging Maintenance Reliability Program Award and the Uptime Magazine’s Best Asset Condition Management Program Award. At MSD, he learned and provided routine PdM services such as thermography, vibration, lubrication, visual inspection, motor testing, and ultra-sonics.


Education and Certifications:

2001-2006- International Brotherhood of Electrical Workers (IBEW) Apprenticeship Program and the National Electrical Contractors Association (NECA) Inside Wireman Certification.

2013- PdM Visual Testing Level 2 Certification & Level 1 Thermographer Certification; 2014- Vibration Analysis Level 1T Certification.