Fuseboard replacement: Advice on minimum insulation resistance level for certificate

[adamant]

Hello, I'm having my old fuseboard replaced, had conflicting advice from two different electricians regarding the minimum insulation resistance levels that existing wiring needs to have in order to pass test - one says it's 5mega ohms, the other says its just 1mega ohm. Can anyone confirm what's the correct minimum, as I'm guessing that if it's the higher level that more wiring might need to be upgraded. Thanks a lot!

 

[MTI]

Re: Fuseboard replacement: Advice on minimum insulation resistance level for certific

cheers for shouting up guys and and happy new year - how ignorant of me lol!

The circuit in question was fully disconned out of board and no simple continuity tests flashed up between the circuit origin which i had removed completely and the rest of the board. I can understand a low parallel path if someone had pinched a P or N somewhere along the line but this circuit has no cpc at all throughout its length. Basically im getting a low reading between phase of the lighting circuit and the MET when the circuit has been removed?

whilst on the subject if you wouldnt mind, im not going to drag up all the crap about PIR's and competant schemes (im part p but not PIR bit) but can we clear this up:

Go to do a mains change. Surely you would have to do a PIR before changing board as I always do? If you aint PIR registered for domestics and it fails, then can you hand over the PIR cert? Luckily i have not had this problem yet.
Surely we all have to give a set price for PIR before we can price a board change and any other remedial action? I know i wouldnt want to be stuck with problems after agreeing a CU change price but ive heard many just change them and go from there simply on an initial visual! Is this how everyone else conducts business? I dont think we can risk pricing a CU change these days without doing PIR first as the results need logging anyway so they may aswell go on the installation cert at the end?

So this lighting circuit, if its near border line anyway (couple of M lets say), would you be happy reconnecting even on rcbo for tripping that circuit only? There is no damp or anything that could be causing the low reading back to the MET as far as i can see. sorry for babbling on!

 

[rich.250]

Sorry meant to say a max of 30ma per circuit rather than 30ma for half of a db in a domestic situation

 

[rich.250]

You don't have to be pir registered to do them, just may be beneficial.... Well that's what they say. If your qualified PIRs now ECRs can be carried out.
All I can think is there is supplementary bonding between lighting and exposed/extraneous conductive part that is earthed/bonded.
Hope this helps

 

[spark 68]

Re: Fuseboard replacement: Advice on minimum insulation resistance level for certific

Go to do a mains change. Surely you would have to do a PIR before changing board as I always do?

I normally do a quick pre-test and a visual, but don't record this as a PIR, or EICR as it is now, just for my own reference, and to know what I need to do.
Obviously I don't want nuisance tripping or find something nasty after the CU change.

So this lighting circuit, if its near border line anyway (couple of M lets say), would you be happy reconnecting even on rcbo for tripping that circuit only?

Only you know the answer to that, being the competant person in charge of the install.

I would personally want to investigate this further, as you could be storing a lot of trouble further down the line, and may be forced to rectify this at your expense.

 

[GLENNSPARK]

Re: Fuseboard replacement: Advice on minimum insulation resistance level for certific

You don't have to be pir registered to do them, just may be beneficial.... Well that's what they say. If your qualified PIRs now ECRs can be carried out.
All I can think is there is supplementary bonding between lighting and exposed/extraneous conductive part that is earthed/bonded.
Hope this helps

yep ...was just going to point out this myth about needing to be registered to undertake PIRs.....these part p schemes need to stop perpetuating this crap n all....

 

[rich.250]

They also need to stop approving the cowboys. Up the minimum standard I say

 

[MTI]

Re: Fuseboard replacement: Advice on minimum insulation resistance level for certific

cheers for your input too. Ill probably open another can of worms here but GN3 im sure says that you should not under any circumstances do an insulation test at the tails. Of course this is by far the quickest method to get a reading before a board change to avoid any nastys but it certainly cant be used as a figure to be relied upon. Any other equipment or hazards that lurk can cause a massive danger by doing this. Its fine on a new initial verification but been the guy in charge, its up to you as to how you conduct business in line with EAWR etc. If there is no risk of danger to property or others then id probably go for it if i was fairly confident in a visual first off

 

[rich.250]

I'm sure it doesn't. It is the preferred method in there

 

[GLENNSPARK]

Re: Fuseboard replacement: Advice on minimum insulation resistance level for certific

cheers for your input too. Ill probably open another can of worms here but GN3 im sure says that you should not under any circumstances do an insulation test at the tails. Of course this is by far the quickest method to get a reading before a board change to avoid any nastys but it certainly cant be used as a figure to be relied upon. Any other equipment or hazards that lurk can cause a massive danger by doing this. Its fine on a new initial verification but been the guy in charge, its up to you as to how you conduct business in line with EAWR etc. If there is no risk of danger to property or others then id probably go for it if i was fairly confident in a visual first off

you dont IR test through RCDs/RCBOs.....they dont like the 500 through em..lol....

 

[spark 68]

Re: Fuseboard replacement: Advice on minimum insulation resistance level for certific

but GN3 im sure says that you should not under any circumstances do an insulation test at the tails.

What page in GN3 does it say that then ?

 

[rich.250]

It doesnt lol

 

[MTI]

Re: Fuseboard replacement: Advice on minimum insulation resistance level for certific

funny you should mention that - we had a big discussion about this on here a few weeks back and agreed its all pants!
Well at the time, funnily enough elecsa's website went down overnight for a few days without warning or even a message on their site saying saying down for maintenance - bad practice. anyway it now appears (correct me if im wrong) that they have removed the page about a seperate fee and assessment for PIR!! phew - just saved a lot of money!!! Not that i intended on doing it but i could of certainly quite easily tagged it onto my assessment last month for the sake of it!

 

[GLENNSPARK]

Re: Fuseboard replacement: Advice on minimum insulation resistance level for certific

no and it aint on the 2391 either as one of the test rigs is an IR board.....and guess where on that board you get your crocs to IR it???...lol....

 

[MTI]

Re: Fuseboard replacement: Advice on minimum insulation resistance level for certific

ill double check - it was an old copy i had from years ago. maybe i ran before i could walk - my bad! may of dreamt it

 

[spark 68]

Re: Fuseboard replacement: Advice on minimum insulation resistance level for certific

I know it doesn't Rich, in fact it says you can test the whole of the installation if it is a simple one with no distribution circuits.