Using a megger for hvac/r

[jayguy]

1000 volt is usually more than enough...i test ALL motors at 1000 VDC. yes, even 115VAC motors and they do just fine.

[hvacrmedic]

I currently don't work on anything bigger than 460/480v.
Is it worth getting a 5000v capable meg ohmmeter ?
Really liking the AEMC stuff. 1050 model has my attention but not my budget :0(

That's a really nice meter. It would be overkill for most of us though. I have the AEMC 1026.

[KnewYork]

1000 volt is usually more than enough...i test ALL motors at 1000 VDC. yes, even 115VAC motors and they do just fine.

Yeah, until you find one that the insulation is compromised. Industry standard for DC test voltages of 120-
240 VAC motors is 500 VDC. Certainly you can continue juicing those little motors to 1000 VDC until your luck runs out.

The manufacturers of 4160 V motors prefer a continuous application (10 minutes) of approximately 2500 VDC rather than shorter durations of 5000 VDC.

[jayguy]

Yeah, until you find one that the insulation is compromised...

that's the goal. at 2mA DC of maximum current, lightning bugs have more power in their butts than a megger. no damage is going to occur unless it was already there to begin with.

[KnewYork]

no damage is going to occur unless it was already there to begin with.

Like Tom Petty says "you can believe what you want to believe..."

[Russ57]

There is a reason why there are megger tests....and then they are hi-pot tests.

A megger test is supposed to be non-destructive. Every insulation class has a rating. We are supposed to be protecting investments, not harming them.