**CU Changes And YOU**

[WayneL]

you will need to make sure you either disconnect the main earthing conductor, or test at the neutral bar with the main switch open (otherwise you'll pick up N-E at the transformer)

You don't disconnect the earthing conductor - and I should hope the main switch is open for a dead test

Jason, I don't understand why your not testing L&N connected together to earth at 250v - it's only a little croc clip fly-lead from neutral bar to bus bar - or am I missing something.

 

[Spudnik]

Jason. I dont really agree with you on all points but Arsenal are on tele soon so I must fly. But in general youre right. I missed out the bleeding obvious because it is just that. But it was good of you to spend the time spelling it out! Cheers!!

The guide i gave was just that.... a guide.

Others may have different ways and im happy to edit with further suggestions.

 

[mattcos1972]

Hi Jason,
Wicked thread mate. Thanks for putting it up.
I have just finished a CU change and as it was my first one, did quite a bit of research on it (as you know, cos you answered about a billion of my threads!!! lol)
I found out some very handy info from 'DurhamSparky' on here, and I am sure he wont mind me passing it on, regarding changing a CU and non earthed lighting ciircuits.
The crux of it was that al lighting and switchgear needs to be changed to class 2 and a label needs to be applied to the new CU stating that the lighting circuit is not earthed and that no metal fixtures can be applied to it.
If the customer does not agree to the changes in their fixtures then a sparky is advised not to go ahead with the CU change.
He also sent me a link to an publication from the electrical safety council, that has been endorsed by NICEIC, ECAetc, outllining the specific requirements

And here it is.....

http://elecsa.co.uk/downloads/public/Reconnecting%20Lighting%20Circuits%20with%20no%20Protective%20Conductor_ESC.pdf

Hope that helps.

 

[DurhamSparky]

no need to thank me!! just thank the Big 3 and the ESC....

 

[robsparky1975]

great topic,thanks jason,similar topic of my own,can you replace old cartridge fuses for plug i mcbs(old wylex unit)without having to notify under part p,i work for a registered firm but will have to wait before going it alone and getting signed up with elecsa,the idea of part p might be good but my word has it not made it even more difficult for qualified sparks working on the cards who in the future set up on their own.

 

[Spudnik]

great topic,thanks jason,similar topic of my own,can you replace old cartridge fuses for plug i mcbs(old wylex unit)without having to notify under part p,i work for a registered firm but will have to wait before going it alone and getting signed up with elecsa,the idea of part p might be good but my word has it not made it even more difficult for qualified sparks working on the cards who in the future set up on their own.

Start a new thread in the relevant forum.

More chance of it being seen in there.

 

[billy110]

Good Q Chris,

I think if you are just replacing the existing tails, then a MWC would suffice.

The Nic man did his annual inspection recently and this topic came. RCBO on a light circuit would require an EIC for that circuit, not a MWC as you are changing the characteristics of the circuit at the point of origin. Changing the main tails would require a full EIC of the installation as you are changing the Characteristics of the whole installation.

Hope this helps

Billy

 

[sythai]

Just a little thing I find useful when doing a CU change.

Rather than changing it all over, go to energise and you now have circuits tripping out.

What I do first (on day of upgrade, not when initially looking at job) is take along an RCBO put that in the old board and check each circuit in that before hand. Just so you don't get any unforseen surprises, that aren't picked up by your inital inspection when you first go to look at the job.

Also that way you can get any issues sorted first, rather than the other way round.... stitched myself up like this once before.... CU swap done by 11:30, nice and easy then powered up only to find lights up, lights down and ring all tripping out. A CU change and test which should have taken 5-6 hours ended up taking me 12 hours (very stressful day) !!

Hope that helps a bit... Sy

 

[acat]

Thanks for the feedback Sy hints and tips are always welcome by everyone on the forum.



Chris

 

[sythai]

No probs....

 

[WayneL]

Just a little thing I find useful when doing a CU change.

Rather than changing it all over, go to energise and you now have circuits tripping out.

What I do first (on day of upgrade, not when initially looking at job) is take along an RCBO put that in the old board and check each circuit in that before hand. Just so you don't get any unforseen surprises, that aren't picked up by your inital inspection when you first go to look at the job.

Also that way you can get any issues sorted first, rather than the other way round.... stitched myself up like this once before.... CU swap done by 11:30, nice and easy then powered up only to find lights up, lights down and ring all tripping out. A CU change and test which should have taken 5-6 hours ended up taking me 12 hours (very stressful day) !!

Hope that helps a bit... Sy

Would it not be easier to do an IR test - 250V L & N connected together and tested to earth?

Seems a lot of messing about fitting a RCBO to each circuit to get the same result that a two minute test will give you - and what do you do with an old Wylex re-wirable board?

 

[mogga]

"and what do you do with an old wylex rewirable doard" Bin it lol

 

[sythai]

Board normally goes in the bin............. unless there is a market for them on ebay !!

"Just so you don't get any unforseen surprises, that aren't picked up by your inital inspection"

I always do a quick IR when first looking at the job, but this for a secondary thing I do just in case the IR didnt pick anything up at the time? Only takes a few mins to quickly try each circuit.

Should have said this is only any good for a domestic sort of situation. Could be a real pain in **** trying to do this with 48way board !!

 

[nadger]

last week i downloaded a pdf file from this site all about changing a consumer unit and your subsequent responsibilities regarding testing etc, i gave my copy to a mate and cannot for the life of me find it again. Please could someone point me in the right direction thanks

 

[Guest123]

last week i downloaded a pdf file from this site all about changing a consumer unit and your subsequent responsibilities regarding testing etc, i gave my copy to a mate and cannot for the life of me find it again. Please could someone point me in the right direction thanks

Probably this one.

http://www.esc.org.uk/pdfs/business-and-community/electrical-industry/BPG1v2_web.pdf