Feature

Motor maintenance: Dielectric testing explained

The insulation system of a motor prevents winding faults, but time, usage, moisture and other contaminants will inevitably cause insulation to deteriorate. Here, Mark Convery, EMS Sales Representative at Houghton International, explains how dielectric testing can detect potential threats to a motor’s insulation system.

04/04/2022 11:24:49

Around 30 percent of electric motor failures are a result of electrical insulation breakdown – the second biggest cause of failure after bearing issues. It is therefore important to identify and predict early signs of insulation degradation for a clear picture of motor health, reducing the risk of unplanned downtime and catastrophic failure.

The electrical testing regime detailed in this article can find early indications of insulation weakness and faults in windings, between phases or coils, and in ground-wall insulation. It can also detect problems with connections, such as feed-cable insulation weakness, motor imbalances, and open or high resistance.

Houghton International begins a testing routine by checking the balance between the motor’s phases using a phase resistance test, then comparing the reading for each phase to identify any anomalies. High resistance in a phase may be a sign of bad electrical joints or breakage within the coil or copper...

Read the full article in the April issue of DPA

Written By Sophia Bell

Sophia Bell is the Group Editor of DPA, Connectivity, and PBSI. She joined the team in 2020 as Assistant Editor after achieving a First-Class Honours BA in English Literature and Film Studies from the University of East Anglia. In her current role, she leads the editorial strategy, driving digital growth and ensuring each title continues to deliver trusted, relevant insight for engineering and manufacturing professionals.