I.R test before cu changeI

[ron55]

Hi Ron,

When testing the RFC R1+R2 cross connected at the CU, and then going round all the sockets, this should have highlighted the problem.

An IR test would not pick this up as there was a break in the circuit, which to be honest, probably made the readings quite good!

It highlighted the problem but only in the same way as the end to end continuity test. It did not help find the break because RI+R2 cross connected at the meter with a break in R2 gives open circuit at every socket on the ring. Linking the 2 N's & 1 cpc (or 2 L's & 1 CPC) was the only way I could think to find the break.

You hit the nail on the head though regarding the IR test and on the basis it was good I went ahead but in future it will make me think.

Cheers, Ron

 

[Spudnik]

It highlighted the problem but only in the same way as the end to end continuity test. It did not help find the break because RI+R2 cross connected at the meter with a break in R2 gives open circuit at every socket on the ring. Linking the 2 N's & 1 cpc (or 2 L's & 1 CPC) was the only way I could think to find the break.

You hit the nail on the head though regarding the IR test and on the basis it was good I went ahead but in future it will make me think.

Cheers, Ron

Yes good point.

This does go to show however, that any testing is not always conclusive.

At least you found the fault.

 

[sivoodoo]

IEE guidance note 3 section 2.7.4 The sequence of tests, sets out the corect order in which tests should be performed.

Regards

 

[ron55]

IEE guidance note 3 section 2.7.4 The sequence of tests, sets out the corect order in which tests should be performed.

Regards

Quite correct and the first on the ring is the end to end continuity.

But also think carefully about the tests and not one of them would help pinpoint this fault, they would only show a fault i.e open circuit. You have to think about ways to locate it and they are not in the book.

Cheers, Ron