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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> CU Help Needed Please https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1092339750 Message started by adamskyj on Aug 12^th, 2004, 8:42pm

Title: CU Help Needed Please
Post by adamskyj on Aug 12^th, 2004, 8:42pm

Hi all,

I wonder if you can help me?

I am confident with electrics but always stayed away from replacing Consumer Units due to the tails from meter issue and unwilling to pull the service fuse.

However moved in with girlfriend who's house has a token electric meter.

The existing CU is full (wilex mcb 6 way) and she wants a shower and underfloor heating.

So i was thinking, in theory, if she doesnt insert any tokens in the meter the electric will cut off and the tails from the meter will not be live until more tokens are creditted and therefore allow for easy replacement.

Any thoughts appreciated

Many thanks in advance

Title: Re: CU Help Needed Please
Post by plugwash on Aug 12^th, 2004, 10:33pm

the meter inputs will still be live though and they are generally under the same cover

i would probablly say pulling the service fuse is a safer option

Title: Re: CU Help Needed Please
Post by adamskyj on Aug 12^th, 2004, 11:45pm

Thanks Plugwash.

I am nervous about the service fuse if im been honest in that i don't know what i will find when i open the seal (never seen inside one) so thought my idea may be safer and less frightening ;D.

The existing meter to cu tails are fine in terms of wear and length so I was intending to leave them in place thus not touching the actual meter whatsoever during swapout.

Title: Re: CU Help Needed Please
Post by L.Spark on Aug 13^th, 2004, 2:22am

I wouldnt really advise any Non-Proffesional body to pull Service fuses, however if you do decide to, ensure that all the fuses in the CU are switched off, or the load is taken off, as this will prevent sparking at the Main Fuse.

Title: Re: CU Help Needed Please
Post by Beanzy on Aug 13^th, 2004, 5:13am

I can hear TN's little wacko paws padding down the corridor already........ any second now he'll burst into the forum saying......

"Chop those meter seals - CHOP 'EM I SAY!"

As for actually contributing anything to your dilemma.... I'd give it a miss on this job for a couple of reasons.

1- if it's a flat you may only have 60 or 63A main breaker and the service fuse probably is about the same. You'll need to do some proper testing to establish if the existing set-up is going to cope.

2- If your girlfriend has to put tokens into the meter it would imply that someone else actually owns the place or the electrical services, so you may get badly stung if you alter it. If it's just an ex council place she's bought, then I'd get the old slot-meter replaced for convenience sake; in which case you'll need to get the job looked at properly anyway.

In all seriousness this is a job you'd be best to get someone in to look at. Pay them for a proper inspection and plan of attack. You may be able to do all the prep and making good to save time & dosh which would be good. But without the proper test kit and the knowledge of C&G2391 proceedures, you could end up with a real nasty one here.

Title: Re: CU Help Needed Please
Post by adamskyj on Aug 13^th, 2004, 11:33am

1- No its a semi with a 100a main breaker so the existing fuse and rig will work

2- Its (currently - in process of right to buy) council owned but they have no problem with fitting of underfloor heating or a shower. The CU has all 6 fuses used and therefore unable to accomodate any further fuses. You could have a valid point about the meter being replaced but at present that is not an urgent issue.

Hope the above clarify's that theirs no reason for this to be a 'nasty one'.

I was simply hoping for someone to confirm my theory or not. i.e with no credit in the meter the tails at the cu end are not live and therefore would have zero risk of injury during replacement of cu for larger cu such as 12 way.

Thanks for your advice.

Title: Re: CU Help Needed Please
Post by Beanzy on Aug 13^th, 2004, 11:52am

Live will be disconnected but neutral may not switch, would depend on meter spec, most switch the pair. I'd snip the seals & pull the fuse anyway, just in case the meter decides to pick that moment to go faulty.

100A should be up for a first shower in most normal sized installations. Are you buying the underfloor heating roll with the earthing mesh already set up, or are you buying the elements and assembling while laying it? I'd give the floor its own dedicated earth while running the shower cable in too. 10mm would be good, & when bonded to the bathroom bonding will give you a reassuring level of safety.

Title: Re: CU Help Needed Please
Post by adamskyj on Aug 13^th, 2004, 1:31pm

Thanks Beanzy for your help

With you mentioning the neutral issue and me being a 'softie' with the fuse i think i'll leave the connection part to the pros.

Once again many thanks

Title: Re: CU Help Needed Please
Post by plugwash on Aug 13^th, 2004, 1:44pm

neutral isn't idolated by the service fuse either

this doesn't really pose a problem especially with most rec backbones up to PME standards nowadays

Title: Re: CU Help Needed Please
Post by adamskyj on Aug 13^th, 2004, 3:01pm

Thanks Plugwash.

Good to know that the process I intend carrying out will be 99% as safe (assuming the meter doesnt decide to go faulty in the 1 hour period taken!) as removing the service fuse.

I will tell the girlfriend to stop feeding the meter for a few days and slap in the new 12 way mk split rcd ive bought from the 'sheds' (i know im sorry ;D)

I willl of course treat the tails, like all other electrical work, with respect at all times whilst 'handling' them.

Title: Re: CU Help Needed Please
Post by plugwash on Aug 13^th, 2004, 3:10pm

just a little word of warning

if your old CU has its main switch further from the meter you may need to replace the tails out of the meter

if you have to do this then you will have to open the meter terminal cover

this will have the cables going into as well as out of the meter

Title: Re: CU Help Needed Please
Post by adamskyj on Aug 13^th, 2004, 4:24pm

A very good point Plugwash!

But I'm lucky, the tails have excess via a loop on each of them �;D �:P

Thanks to all your advice and concerns it really is appreciated.

Title: Re: CU Help Needed Please
Post by L.Spark on Aug 13^th, 2004, 5:19pm

Good job then id say, because removing the cover from the meter leaves a selection of live terminals, and is also not legal.

Stick with what your doing, and in your case the Neutral at that point is considered adequately Earthed to the Network so doesnt pose a danger.

Anywhere else this would be considered a live conductor.

Good luck & Be carefull

Title: Re: CU Help Needed Please
Post by plugwash on Aug 13^th, 2004, 8:48pm

we know you are not technically supposed to touch rec kit

we also know that most sparkys here just get on with it because recs are so bloody slow eh ls

LSs idea of a temp supply ;) (note to diyers don't mess with 3 phase)

Title: Re: CU Help Needed Please
Post by L.Spark on Aug 14^th, 2004, 12:26am

now now thats naughty Plug!

you and I both know that for an electrican it's different, we've talked about this.

and anyway I personaly sealed it all back up so as to keep fingers out ;)

Nothing wrong with my Temp Supply! :)

Title: Re: CU Help Needed Please
Post by plugwash on Aug 14^th, 2004, 12:58am

how exactly did you reseal it?

Title: Re: CU Help Needed Please
Post by L.Spark on Aug 14^th, 2004, 2:11am

erm.. with meter seals, kindly donated by EDF Energy, want to know anymore?

and EDF energy aint up where you are I dont think or iirc in ur terms ::)

Title: Re: CU Help Needed Please
Post by plugwash on Aug 14^th, 2004, 2:15am

you managed to get real rec meter seals?

sounds like some dogy dealing there ;)

Title: Re: CU Help Needed Please
Post by L.Spark on Aug 14^th, 2004, 2:20am

how dare you suggest such things!, just a kind donation, nothing more, nothing less �:)

p.s. learn to spell :D

Title: Re: CU Help Needed Please
Post by Beanzy on Aug 14^th, 2004, 4:06pm

Just ordered my meter-seal press and die from Seton direct. They'll do you three letters. Not cheap but it's a once in a lifetime buy. And the rec sparks dont' care if it's one of theirs or not, just so long as they know joe soap hasn't been rippping them off. Now I seal them up and go. However I do have a friend who's a jeweller who said he'd do me a nice SWEB logo on a die for me. ;) Not taken him up on the offer yet though.

Title: Re: CU Help Needed Please
Post by dingbat on Aug 14^th, 2004, 8:44pm

When the rec updated my service head I had a chat about pulling fuses. The lads promptly handed over a big bag of seals and wires. They'd far rather you left a cutout or meter sealed up when you left a job than leave it open to abuse.

Title: Re: CU Help Needed Please
Post by L.Spark on Aug 15^th, 2004, 1:16am

Yes, thats most definatly true Dingbat, only really thought of kids mostly.

must get some more seals! :)

Title: Re: CU Help Needed Please
Post by Lectrician on Aug 15^th, 2004, 8:47am

The seals used down here are 3 letters only. WPD :-)

Title: Re: CU Help Needed Please
Post by dingbat on Aug 15^th, 2004, 11:08pm

Beanzy's seal press sounds good. I had a look on Seton's website, but it didn't give prices for the seals themselves. Perhaps Beanzy'd be good enough to let us know if it's a good investment - or whether the seals cost a quid a piece ;D!

Title: Re: CU Help Needed Please
Post by Beanzy on Aug 16^th, 2004, 9:06pm

Not cheap I'll admit but only use a few per site

http://www.seton.co.uk/perl/product.pl?productid=1117

Depends if you use Monel or Copper (cheaper)

Title: Re: CU Help Needed Please
Post by Lectrician on Aug 16^th, 2004, 9:36pm

Ehh - �100plus for 1??

Title: Re: CU Help Needed Please
Post by adamskyj on Aug 18^th, 2004, 12:30pm

Well im still here and the consumer unit works dandy ;D

Thank you for all your help

Title: Re: CU Help Needed Please
Post by scotspark on Aug 18^th, 2004, 10:11pm

crimper is less than 1 seal????????????

something aint right

Title: Re: CU Help Needed Please
Post by plugwash on Aug 19^th, 2004, 1:49am

i would guess those prices are per pack

how many are in a pack the website doesn't seem to say

Title: Re: CU Help Needed Please
Post by L.Spark on Aug 19^th, 2004, 3:37am

THEY SUCK, oops caps ;D

ought to sort there site out, loads of websites have messy or no information, especialy the prices! ::)

Title: Re: CU Help Needed Please
Post by Beanzy on Aug 20^th, 2004, 8:59pm

Yep it's pants. Think price is for a ton of them but I'm using old ones for now and i don't know how much they were....just can't recall ..... ahem!

Don't even have a box on the order for inserting the letters to customise it. Have to e-mail you once they get the order.... very klunky. :-/