EC&M Tech Talk - The Why, What, and How of High Potential (HiPot) Testing

In this EC&M Tech Talk, Randy Barnett, NFPA Certified Electrical Safety Compliance Professional, demonstrates how to safely use a high potential test set (HiPot) as he conducts an AC Dielecrtic Withstand Test.
Here is the Tech Talk in a nutshell:
• After a brief introduction into the terminology of the topic, Randy demonstrates the how-to side of safety when it comes to performing any test at greater than the insulation rating of the equipment.
• The difference between the dc Insulation Resistance Test and the High Potential Test are presented, then a dc insulation resistance test is performed.
• Important References are presented.
• The AC Dielectric Withstand Test basics are explained.
• A dc Insulation Resistance is performed on a 460 vac motor.
• An AC Dielectric Withstand Voltage Test is performed on the AC motor. Closeups of the HiPot screen shows how to setup the test set.
• Various HiPot applications bring the Tech Talk to a close.
If you have a need to learn what high potential testing is all about, or just want to learn more about testing methods, viewing this EC&M Tech Talk can be of great benefit.
HiPot Safety - 00:51
dc Insulation Resistance testing vs. HiPot testing - 02:28
Important References - 03:30
The AC Dielectric Withstand Test - 04:10
Performing the dc Insulation Resistance Test - 04:45
Performing the AC Dielectric Withstand Test - 09:40
HiPot Applications - 16:33

[@bobbyyoung2831]

Why test a motor insulation that is only rated for 600V at 1000V? Will you not cause damage to a new motors insulation? Should you hold the Megaometer whilst doing the test without gloves? Thanks for the class.

[@electricrb]

Thanks for the comments and good questions. Since we will apply 480v - 600v to the motor we want to make sure it will withstand at least that voltage level. Spikes and surges will definitely occur during operation. The megohmmeter must receive an inspection daily before use and meet the inspection requirements of NFPA 70E Standard for Electrical Safety Maintenance in the Workplace. As long as the meter itself has passed the inspection and is located outside of the restricted approach boundary of 18" or 2'2" depending on the voltage level, insulated gloves would not be required.