Insulation test

[mrloy99]

Hi All.Bracing myself here for torrents of abuse.
Is there any reason why an I.R. test can't be done at a socket rather than at consumer unit.

 

[Richard Burns]

An IR test can be performed at any point in the circuit so long as it is all continuous (i.e you do not remove the cables from the socket) , however if the cables are still connected in the consumer unit then they will also be (for Neutral and earth) connected to the other circuits, whilst it is advisable to have the earth still connected to ensure there are no other earthed parts that may short to line or neutral, having the neutral connected will apply 500V to one side of the other circuits and this may give incorrect results and possibly cause damage to connected equipment. Also if the circuit is only switched off at the circuit breaker and the main switch is still on there will be a neutral earth connection either at the service head (TNCS) or at the sub station (TNS) which will give false results.

 

[Silly Sausage]

Hmmm, probably not the best place to do an IR test from, for the reasons Richard states.
You're not thinking of doing R1R2 tests from a socket as being wrong? Some people insist it's wrong.
Perfectly fine I say.

 

[mrloy99]

An IR test can be performed at any point in the circuit so long as it is all continuous (i.e you do not remove the cables from the socket) , however if the cables are still connected in the consumer unit then they will also be (for Neutral and earth) connected to the other circuits, whilst it is advisable to have the earth still connected to ensure there are no other earthed parts that may short to line or neutral, having the neutral connected will apply 500V to one side of the other circuits and this may give incorrect results and possibly cause damage to connected equipment. Also if the circuit is only switched off at the circuit breaker and the main switch is still on there will be a neutral earth connection either at the service head (TNCS) or at the sub station (TNS) which will give false results.

I was thinking to test the I.R.of the whole installation..main switch off ,cbs on and useing a shorting plug to join neutral and earth at the other half of the double socket. Of course continuity testing first...and then operating the 2 ways and all that,Same deal for testing at the board if there's electronic stuff that might get fried disconnect /test at 250 .

 

[mrloy99]

Hmmm, probably not the best place to do an IR test from, for the reasons Richard states.
You're not thinking of doing R1R2 tests from a socket as being wrong? Some people insist it's wrong.
Perfectly fine I say.

I dont see any problems either from doing the ring tests at a socket either..in fact sometimes its handier can use the terminals to cross link for fig.8 tests..sometimes its quite difficult to disconnect in the board and be sure that you have the right set of neutrals.Also in a socket its usually easier to distinguish the ins and outs

 

[Deleted member 26818]

You want to short out neutral to earth?
Why?

 

[mrloy99]

You want to short out neutral to earth?
Why?

Sorry meant to write neutral and live.Missed the cutoff time to edit

 

[HandySparks]

Nothing wrong with testing in ways other than 'to the book', providing that you think through all the consequences and fully understand what you're doing, which clearly you do. I agree that ring continuity is often much easier at a socket than the board.