How the insulation tester works

Hey GFM, always enjoy your videos. Just wanted your opinion on those Supco M500 meggers, the ones that only have an LED scale, no number readings.

Would you say they're decent meters for checking the insulation on residential ACs?

Thanks!

informative...

Thanks eh...     Ü

I have an old megohm analog meter and I found this guys compressor to read less that 10 megohms and I though ok the compressor is shot, so I got out the digital supco megger and it read 20 which is as low as it can read and says to replace the compressor. Well I'm here to tell you thats been well over a year ago and its still running lol and drawing rated amperage go figure

GFM, I read somewhere if you notice a downward trend or low megohms that it's possible you might have containments such a water in the system slowly generating acid and eating away your wire insulation. It was recommended to pump down the system and replace the filter dryer or if really bad readings replace the filter dryer twice.
I would like to know what your thoughts are on the subject and if it would be worth the trouble.

how does a 9v dry cell supply give 1000v in an electronic tester to test insulation?Is it just a simple voltage transformer inside the tester?

good video. and thanks for taking your time to explain the process.

Thank you very much. Great explaination.

i need to know how to take an insulation test. i need to test a set of cables and don't know how.

Thanks a lot for sharing, I think that you have made the best explanation!
I hope that you please will answer my noob question. I want to test old insulation, glue, foam and so on, used in old amplifiers, if it is become conductive over the years. Is that the right tool for the job? (considering it's name) :-)

Im just buying my first insulation tester and this is the most informative video explanation ive seen so far on how to use on windings.

Why aren't you using Kelvin Clips with the insulation tester on the left? I know they do not come with it, but that's what should be used for accurate testing.

Why would anyone use a meter that utilizes only 9 volts to test a compressor that runs at 240 or 440 volts. The motor isn’t running at 9 volts so why would anyone use a standard ohmmeter to verify the condition of a compressor. A compressor that is full of liquid refrigerant will fail a megger test. It’s the reason for a lot of burnouts on units that are started up without the crankcase heaters being energized for 24hrs prior.. We teach and stress the use of megohmmeters in our apprenticeship program. In fact it is a part of annual service on large equipment to Meg the compressors and all motors. A Megger will detect insulation faults in a unit that are causing nuisance trips of fuses and breakers, where an ohm meter will not. Every pro HVAC tech should have one.

you never showed a single test example !?

Would you use an Insulation Tester on a Condensing Unit conductors between a panel and disconnect? If so, can you demonstrate that?

It doesnt measure "millionths of ohms"
It measures in megaohms which is x10^⁶ . Ohms. Millions of ohms..

This kind used to test dc charging pile

The meter on the right is if it is supposed to be stuck then it will confirm its stuck

The meter on the left is for if it is not supposed to be stuck, it will confirm if it is stuck!

Connections, Electrons, Resistance, Continuity, Open/Closed etc is what i mean!!!

Wire with hole in it = possibly stuck! How much? Crank up the voltage!