OI Roundtable

Hello people,

What is the difference between a motor megger and an insulation tester?

I am going to purchase and insulation tester for our maintenance shop. I see both terms used loosely and I really don't think there is a difference, but can anyone detail these two items so I make the right buy. Thanks very much for any insight.

QuoteWhat is the difference between a motor megger and an insulation tester?

Megger is the name of the insulation tester that was manufactured by The James Biddle Company. A motor megger or just plain Megger IS an insulation tester.

Not sure when they the James Biddle Co began manufacturing Meggers, but the name caught on in the same way we typically use brand names like Band-Aid (instead of bandage).

Here's an old photo of a hand operated Megger from an operating manual:

(http://www.obsoleteindustrial.com/photos/motor-megger-from-manual.jpg)

Here's an photo of a hand operated Megger from an operating manual:

(http://www.obsoleteindustrial.com/photos/old-hand-operated-megger.jpg)