Consumer Unit replacement, suppliers fuse, old cable colours etc.

[redlitchfield]

Hi,

It's my first day on the forum and thought I'd kick off with a few questions.

I've got my first consumer unit replacement to do in the next couple of weeks and would like to clarify a few points.

Here is a photo of the original fuse board:

- As I didn't do the original install (40 odd years ago) am I permitted to do the inspection, testing and certification even though I have yet to do my 2395. I am using this job for my NAPIT assesment.
- The cables coming in are old red and black cables and I will be running new circuits in for a kitchen extension soon. Will I need to just use the "Warning, wiring to different versions of BS 7671..." sticker on the new consumer unit or replace the old cables.

Thanks,

Red

 

[Guitarist]

Only the DNO can touch the main earthing arrangements. They may be willing to take a larger cable to an earth block for you if you need one.

 

[redlitchfield]

Just an update. Scottish and Southern Energy Power Distribution said I could cut the tag to remove the fuse and then go to their local depot to get a temporary tag until they come and replace it with a proper one. More straightforward than I imagined!

 

[Spudnik]

The sse have been quite good recently with this.

It still a good idea to contact them first though.

Also a lot of the new meters they are fitting are self connect with a built in isolator.


Sent from my iPhone using Tapatalk

 

[GLENNSPARK]

you need to IR test this install first before replacing with a new C/U that will undoubtedly contain earth-leakage devices....how do you know there aint a borrowed neutral here...you`l need to test for that....a thorough inspection of the install would be prudent here as well....i mean...is there even a CPC on the lighting circuits....it just goes on.....what i am trying to say is this install requires an EICR undertaking on it first BEFORE you procede with anything else....list owt you find that needs sortin....its your 1s and 2s your looking for....and dont forget those essential tests.....

 

[GLENNSPARK]

whats the earthing arrangements here?...done a Ze?....how do you know you have a reliable means of earthing?....your PFC at the origin of supply may dictate the choice of MCB you need as well.... these are all things you need to check first.....

 

[GLENNSPARK]

when it comes to formal inspection ant testing certs...such as the C&G2391...it isn`t a requirement to have em....but they are a way of proving competency.....just be careful though with napit as they have a watered down version of the 2391 which they try to push.....it aint worth a jot outside of napit...unlike the C&G version...

 

[redlitchfield]

Hi Glennspark,

I've already told the client that I will first be doing a thorough inspection and test for the things you've mentioned like borrowed neutrals, lack of cpc's etc. and that anything untoward will need to be sorted before I proceed. He told me that his father in-law used to do 'a bit of electrical work' in the past and when they wanted more sockets they used to get him to do it, so I'll be checking out any spurs etc. Funnily enough he mentioned to me that a friend of his had a new CU fitted and something constantly trips it!

Yeah, I'm going to do the new C&G 2395 at Basingstoke college later in the year

 

[GLENNSPARK]

Hi Glennspark,

I've already told the client that I will first be doing a thorough inspection and test for the things you've mentioned like borrowed neutrals, lack of cpc's etc. and that anything untoward will need to be sorted before I proceed. He told me that his father in-law used to do 'a bit of electrical work' in the past and when they wanted more sockets they used to get him to do it, so I'll be checking out any spurs etc. Funnily enough he mentioned to me that a friend of his had a new CU fitted and something constantly trips it!

Yeah, I'm going to do the new C&G 2395 at Basingstoke college later in the year

well as for the friend of his that has the tripping problem....could be your first paying customer there.....as for this install....go for the obvious stuff first....such as the `extras` he added on...and any other signs of disturbance....normally on a PIR/EICR...you would go for 10% sampling to start with..but keep an open mind.....any crap...then up it to 50% and so on....i would suggest you start at 50% here...go for the things he added for em...then move on....your tests will usually reveal if theres any flim-flam going on with circuits n stuff....IR between neutrals to find the borrowed neutral
(if its there)....and as has already been mentioned....check both earthing AND bonding...CSA and R2....

 

[GLENNSPARK]

dont forget when IR testing that neons and outside lamps will affect the test...so watch out for em....passives, variable resistors and smokes n heats dont like the 500.....so a good practice is to always set your insulation resistance tester to 250V first and test at that to be sure theres no connected loads anywhare.....before upping it to 500V....and that goes for any testing other than an initial verefication......

 

[redlitchfield]

Thanks for that Glenn. This forum has proved in less than a week to be a valuable tool for people's real world advice and opinions, rather than a sterile text book description. I shall keep you updated on my progress/findings/results/how much swearing id involved etc!

 

[redlitchfield]

Hi all,

After all that the customer has decided not to go for the consumer unit change and a friend is going to wire his kitchen extension of the old C/U and and run it to a small consumer unit for RCD protection on the sockets etc.

Looks like I'll be changing my own consumer unit now for my NAPIT assessment. I'll let you know how it all goes!

 

[Guitarist]

Much easier to do your own. The assessor has less travelling, you can offer him tea and biscuits, plus you will know your own wiring system like the back of your hand. Good luck.