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Author Topic: Megohmmeter  (Read 6025 times)

Stephen Swaffer

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Re: Megohmmeter
« Reply #10 on: November 05, 2014, 01:45:15 pm »

99% of the time I use a megger for "real" work I really don't care about accuracy that much.  If it is a new wire run I want an open reading.  Motors are different-they can show some conductance, but I really am just looking for a ballpark idea-same thing with an underground feeder.  IMO accuracy would really only be a concern for production testing when you need to meet a spec.
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Steve Swaffer

Mac Kerr

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Re: Megohmmeter
« Reply #11 on: November 05, 2014, 02:19:33 pm »

The AC voltage readings are high (130/266V when the Fluke says 127/255V) on my house voltage.

A man with one meter is always sure, a man with two meters is never sure.

Mac
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Jay Barracato

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Re: Megohmmeter
« Reply #12 on: November 05, 2014, 02:48:53 pm »

A man with one meter is always sure, a man with two meters is never sure.

Mac

Depends on his calibration protocols.

Sent from my DROID RAZR HD using Tapatalk

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Jay Barracato

Tom Bourke

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Re: Megohmmeter
« Reply #13 on: November 05, 2014, 03:07:55 pm »

A man with one meter is always sure, a man with two meters is never sure.

Mac
220 221, what ever it takes.
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Lyle Williams

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Re: Megohmmeter
« Reply #14 on: November 06, 2014, 03:10:55 am »

While in theory for some tests 1.001Mohm might be a pass and .999Mohm might be a fail, the reality is you are generally looking for hundreds of Mohms and anything vaguely close to  the expected threshold needs investigation.

Insulation also varies significantly with temperature and moisture/humidity.  If you aren't adjusting readings for temperature and humidity, there is little point caring about calibration certificates etc.  It is worth having some high value resistors in the bag with the megger so you can verify the device is operating correctly.
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ProSoundWeb Community

Re: Megohmmeter
« Reply #14 on: November 06, 2014, 03:10:55 am »


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