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That's interesting, I did that on the practical and got picked up on it (verbally slapped)In the 2391 I went on the ... RCD (i.e. the buzz bar) without any issues.
Discuss Ir tests in the Periodic Inspection Reporting & Certification area at ElectriciansForums.net
That's interesting, I did that on the practical and got picked up on it (verbally slapped)In the 2391 I went on the ... RCD (i.e. the buzz bar) without any issues.
It still remains that everything should be terminated before IR testing - so you couldn't go on the bare ends of stripped conductors.
Bearing in mind the regs have only just been ammended, you'ld think they'ld have altered the above regulation (sorry, 'guidance'), if it was a problem.
In the 2391 I went on the outgoing side of the RCD (i.e. the buzz bar) without any issues.
The problem you've got is, if you do as you(jimmyboy) and telectrix suggest, by testing each circuit seperately and disconnected from the CU, you could still have issues between circuits.
I'll just give you a very quick example so you know what I'm on about :
Conduit install, you IR test L-N on a socket radial, (disconnected from board) - 500v >299 M everything rosy.
Unknown to you, though, the 'line' conductor you've just tested is shorting out to the neutral of a lighting circuit (within the conduit).
It won't be picked up because you had the socket radial circuit's conductors out of the board.
The same thing can apply to CPCs - you IR test L-CPC with the conductors disconnected from the board - >299...........but what if the 'line' conductor has been snagged on some earthed metalwork somewhere - again, it's not gonna show up.
This is the reason you test with all conductors terminated.
If you have sensitive equipment in circuits, then, as the regs state, you have to compromise some of the testing, but the fact remains you should IR test as much of the installation in it's finished (terminated) condition as possible.
Just dropped into this one. Hope to resolve an odd L-E IR reading by using the aforementioned old school method of dividing into two, then four. Much better than disconnecting everything an running seperate leg IR tests. All other dead/live tests are fine on the circuit. Just the puzzling IR reading (L-N >1000, N-E >1000, L-E >725). All well within guidelines/regs but just a tad puzzling! I don't like unsolved puzzles :dizzy2:
A value of 725 Mohms is well above the maximum that some testers read to (300Mohm) so that result is absolutely fine. If you were testing a new install and got 75 Mohms then I may be slightly concerned.
14 years is plenty of time to have got to 750 Mohm even if it did not start at that.
It's only the protective conductor which has to be connected when testing.
Took me a while to figure out what a buzz bar was. Assume you mean busbar?
A value of 725 Mohms is well above the maximum that some testers read to (300Mohm) so that result is absolutely fine. If you were testing a new install and got 75 Mohms then I may be slightly concerned.
14 years is plenty of time to have got to 750 Mohm even if it did not start at that.
Reply to Ir tests in the Periodic Inspection Reporting & Certification area at ElectriciansForums.net
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