Insulation Resistance recording

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Chris_81

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I recently rewired my Dad's garage and have been doing the tests on it as building control told me they don't anymore, I have to!

Anyway, as most of the work I've been doing has been with other sparkies I haven't done much in the way of testing. When I did my course the IR testing in the small booths on the flukes we used always went up to 500m ohms as they were highest figure on there and that was what was recorded on the sheet. Testing the garage with the Metrel tester I've got the figures keep going up all the time the button is pressed. ie start around 100 and steadily increase, not reaching the mazimum of 1000 that it reads.

How would I write this on the certificate? Do I have to keep holding the test button down until it stops, seems to take ages. (Ring was fine, only the lights its doing this on) or is there a certain figure once it goes past I can write down?

Sorry if its a stupid question and hopefully it makes sense!

 
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You should record the highest figure even if it takes a little while, however as anything over 1 Meg ohms is legal, and anything over 2 MegOhms doesn't incurr the wrath of NICEIC recommendations, then I would simply record what it shows after 5 seconds, or the initial point at which the rate of resitance rise slows down. I sometimes get a similar thing with my megger whereby upto 260 MOhms the dial shows rapid rise but then 'flutters' about until it reads the max of 299 MOhms.

 

Chris_81

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That's a good point actually, never tested a light circuit before that's all flourescent tubes, usually only a couple at the most, not seven!

So would that mean I need to record the figure like binky said?

 
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