When most people think reliability, vibration analysis is the first thing that comes to mind. But what about the electrical side of your motors. That’s where a lot of hidden damage is happening and it’s often ignored.

In this episode we get into shaft current. It’s been around since variable speed drives first hit the scene but it’s still not well understood and definitely not well managed. These stray electrical currents eat away at bearings and windings, quietly cutting motor life down by decades. The scary part is that from what we are seeing around 90 percent of drive installs haven’t been designed properly to deal with it.

I reference the teachings of electrical condition monitoring expert Mark Gurney to break this down. We look at how to actually detect the issue with oscilloscopes, Rogowski coils and the SKF TechEd tool. We explain the difference between common mode and circulating currents and why quick fixes like grounding rings aren’t always the silver bullet people think they are. Done wrong they can even make the problem worse.

We also talk about Motor Current Signature Analysis MCSA. For me this is the future of motor testing. It gives you the ability to pick up not just electrical faults but mechanical ones too. Bearings rotor bars even belt tension can all be identified just from reading the motor’s electrical signal at the MCC. If you’re serious about IoT and advanced monitoring MCSA is a game changer compared to just scattering sensors everywhere.

The bottom line is this. Why are we okay with motors failing after 10 years when they are designed to run 30 or 40. It’s time to move beyond only looking at vibration and start treating electrical testing as a key part of reliability. Our most critical assets deserve that level of care.

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