Insulation Resistance??

[Des 56]

I but surely it suggests that there is something not quite right on one of the circuits?

Best to ask yourself why we do the insulation test

eg
What are the effects of heat ,age, mechanical damage etc and what they mean to the results of the insulation test that is being done on your installaton

 

[Jimmy Boy]

Does anyone/Has anyone used test method 2 in GN3 as stated in regs book 612.3, where to join the 2 Line conductors together and test to earth ? this removes the need to disconnect sensitive equipment and must be quite useful if you have a circuit full of fluorescent lights or similar.

 

[semaphore]

Steve,
"Does anyone/Has anyone used test method 2 in GN3 as stated in regs book 612.3, where to join the 2 Line conductors together and test to earth ? this removes the need to disconnect sensitive equipment and must be quite useful if you have a circuit full of fluorescent lights or similar."

We use this method virtually all the time. I'ts very rare we can disconnect equipment.
I think you mean join the line(s) and neutral together and IR test between the live conductors (joined together) and Earth.

 

[Jimmy Boy]

Thats what I meant yes I was calling the Neutral a Line conductor I should have said 'Live' conductors

 

[Risteard]

I'm not being funny, but are you confusing an insulation resistance test with an earth fault loop impedance test?

No, I'm not.

Insulation Resistance should be performed with the system de-energised and the means of earthing attached.

 

[Risteard]

What do you do if you find a fault, just say 'oh, there's a fault somewhere on the system. Oh well.'?

You open circuit breakers or remove neutrals until you find the faulty circuit. That is why it says that below 2 Megohms requires further investigation. This is the further investigation.

 

[rocker]

You open circuit breakers or remove neutrals until you find the faulty circuit. That is why it says that below 2 Megohms requires further investigation. This is the further investigation.

Which, for the billionth time, is what I do to start with, because, for the billionth time, there is no need to test the full installation if you are only working on one circuit.

 

[rocker]

Just realised my last post comes off as really chippy, which was not what it meant to sound like. Just find it odd that we've all been taught in different ways.

 

[Risteard]

Which, for the billionth time, is what I do to start with, because, for the billionth time, there is no need to test the full installation if you are only working on one circuit.

I'm not talking about working on an individual circuit.

I am pointing out that insulation resistance is cumulative.

And no need to apologise.