Megohmmeter Voltage

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Ken_S

Senior Member
Location
NJ
Occupation
Electrician
It all depends on the type (degree of resistance) you have. Sure, an ohmmeter is fine for dead shorts. A megger not required. But using a ohmmeter on a high resistance short is useless. That's why a megger was invented. I suggest you google "A stitch in time" by megger, you may learn something.
I read that about 15 years ago, a megger has it's place, but a good quality DMM is an extremely useful tool for finding many everyday issues.
 
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
It all depends on the type (degree of resistance) you have. Sure, an ohmmeter is fine for dead shorts. A megger not required. But using a ohmmeter on a high resistance short is useless. That's why a megger was invented. I suggest you google "A stitch in time" by megger, you may learn something.
I agree that a megger is a good tool but define high resistance short. Are you telling my Fluke 87 is not capable of measuring 20 mega ohms, 200k, or 2K?

My Fluke 'megger' tells me at what voltage the insulation has failed at, be it 24 or 672. (Random #s). For sure higher than the 9 volt but to blanket all ohm meters as worthless is not correct. IMO.
 

ATSman

ATSman
Location
San Francisco Bay Area
Occupation
Electrical Engineer/ Electrical Testing & Controls
I agree that a megger is a good tool but define high resistance short. Are you telling my Fluke 87 is not capable of measuring 20 mega ohms, 200k, or 2K?

My Fluke 'megger' tells me at what voltage the insulation has failed at, be it 24 or 672. (Random #s). For sure higher than the 9 volt but to blanket all ohm meters as worthless is not correct. IMO.
Show me where I said all ohmmeters are worthless?
 

paulengr

Senior Member
Hello,
When Testing 600V conductors with a megohmmeter, is it permissible to use the 1000V setting on the meter?

Use the voltage specified by the standard that you are following. Don’t make things up.

Insulation systems have 4 currents that you are measuring. One is leakage, what you want. The other three dissipate over time, so the readings change with time. If you want repeatable results, you MUST use the same voltage and time called for by the standard.
 
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