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What's an acceptable resultOne megohm on a new circuit. Pass?
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A good circuit
Display: > 2000 MΩ Record exactly that: >2000 (the > symbol matters — you're saying "at least")
§The book's minimum for a low voltage circuit is 1 MΩ. One million ohms conforms to the requirements.
✋But read the note underneath it, because this is the bit worth highlighting. The book says an insulation resistance value as low as 1 MΩ would conform — and then goes on to say that a new installation should not yield a test result that low, and that in new installations any value below 20 MΩ should be investigated.
So what do you actually do with a 1 MΩ reading on a brand new circuit? You investigate it. It passes the letter of the regulation and it tells you something is wrong. Your instrument reads past 2000 MΩ for a reason.
GN3 · 2.6.7 · p.70 · minimum insulation resistance · the 20 MΩ note (new installations) ★
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