Testing after a consumer unit change

[Andy78]

This guide states after a board change, do not to reconnect any circuits with C1 or C2 faults. Is this backed up by regulation?

I think the EAWR regulation 4 would apply.

 

[Pete999]

Not seen that before; a step by step guide on how to change a consumer unit..
what next.. electrics for dummies?

Judging from dome of the questions asked, Charlie, seems like a good document to read before attempting a CU change!!!!!!!!!!!!

 

[Marcus Vaughan]

Always do the tests before which are end to ends and Zs at every accessible point on rfc, lighting Zs but at switches if a ceiling full of downlights and dimmers involved, Zs on any radials. L&N - E ir for each circuit. Additionally when more than 1 lighting circuit I do a functional test (look) by disconnecting the neutral to make sure it is not affecting the other circuit (borrowed neutrals). After change Zs on a few random points and compare with original readings to confirm my earth terminations, Ze and rcd trips. Feels like an assessment answer!

Brilliant.

 

[Dustydazzler]

His opening statement was that he changed 40 consumer units

Changed as in past tense ?

 

[Charlie_]

Judging from dome of the questions asked, Charlie, seems like a good document to read before attempting a CU change!!!!!!!!!!!!

Yes, most definitely so!!
I’ve just read through it and I can see that could be a very useful document

 

[buzzlightyear]

I’ve just read through it and I can see that could be a very useful document

what next.. electrics for dummies

you said it ,LOL.

 

[ruston]

Lol , the opening post reminded me of two mates trying to outdo each other with the best lie. One said " I paddled up Niagara falls in a canoe". His mate replied " I saw you"

 

[Charlie_]

Changed as in past tense ?

Is that a trick question or do you genuinely not know?

 

[Diver233]

Changed 40 in one day, wow. I know I am mainly a fire alarm engineer but even if there is only a lighting, socket circuit in each I cannot see how you can do 40 in a day. Even working a 20 hour day it’s two every hour.

 

[Dustydazzler]

Is that a trick question or do you genuinely not know?

Sorry

Yes I know it’s past , as in they have already done 40 consumers units

My point was if they have already done 40 and now looking at possibly doing some testing after the fact , then aren’t they putting cart before the horse

 

[Tony Reidy]

Had to change 40 consumer units the other day in a hostel/hotel/b&b and it come to the testing stage


I spoke to the NICEIC who said you need to test circuits for " safety only ". He said doing a global IR test (testing each individual circuit if less than 1M), and earth fault loop, RCD and end to end to any ring mains. He said not to bother with R1+R2 or R2 test as polarity would be verify due to the Zs test.

How much depth do you do?

40 in a day wow, I'd fit one and test it then go for a pint to celebrate a successful day

 

[Dustydazzler]

I’ve got it...

They have changed a 40 ‘circuit’ consumers unit the other day

And are now possibly contemplating which tests might need doing and not doing

 

[rolyberkin]

Who cares, 40 consumer units, £30 a circuit…..............!

 

[Dustydazzler]

Who cares, 40 consumer units, £30 a circuit…..............!

Too cheap

 

[Rpa07]

OP hasn’t been back since post #6 - they’ll have a bit of reading to catch up on and some explaining to do!

 

[richy3333]

OP hasn’t been back since post #6 - they’ll have a bit of reading to catch up on and some explaining to do!

Probably busy doing another 40 boards

 

[Gavin John Hyde]

it also comes down to size of the installation, number of circuits etc..
in terms of domestic and not a commercial 3 phase then
As already said by others for me it would be as a minimum
Ring - end to ends
Zs for each circuit as it confirms the polarity, If time permits then R2 with a wander lead or I might link busbar to earth bar in the cu with mcbs all open for a R1/R2 at random points on circuits, if anything pops up then then give that circuit some more attention.
IR - I would as a minimum do LN joined>E if there is lots of neons and fixed lights etc. as It can be a slow process to disconnect it all.
RCD/RCBO trip times on all devices
Then usual Ze, PFC, PSC, check bonding etc..