What is online motor testing?

Testing a motor while it is running. We can see the current draw on the motor at the time of test, hidden frequencies, the health of the rotor, and even eccentricity. Online testing is non-invasive. No need to stop production or disrupt processes.

What is offline motor testing?

Testing a motor when power to the motor is off (locked out or removed). This test can be done while the motor is still installed in the field and can be performed from the starter cabinet. It can also be performed before the motor is installed (baseline) or removed (motor replacement).

How often should online/offline testing be performed?

At a minimum- Yearly. Ideally- every 6 months.

Industrial motors often run 24 / 7 / 365. They drive conveyors, pumps, agitators, elevators, cranes, winders, fans, etc. Knowing the health of your motors is the key to a successful maintenance program.

What are we looking for?

We are trending the motor. Upon install, we believe the motor to be in A+ condition. But as the motor drives equipment it is under stress. Heat, overcurrent, moisture, dirt, frequent starts and stops all contribute to the demise of a motor. By trending a motor every 6 months, we can see the motor’s health.

Instead of Reactive Maintenance for a grounded motor, Predictive Maintenance would have foreseen the motor insulation failing.

Which is better offline or online?

Both should be performed. Offline during a scheduled maintenance period is ideal. Online during production under normal conditions is ideal.