Replacing a Consumer Unit - Cable too Short

[jenki]

Hi - Can anybody give me some advice please? - I want to Change my CU to a Split load RCD unit as the current CU is only 4 way - and I want to add a Shower Circuit. I know that the cables inside the current CU will be too short - what is an acceptable way to increase the Length of the conductors - I was told that Connector blocks are ok with BS7671 - but I would prefer to use crimps - any ideas?? -

Just read numerous previous posts on Crimping, Jbs etc, - must point out that the all the wires come in from the back of the CU, positioned at ceiling level - so jbs are no good - So to revise my question - Should i use Crimps or Choc blocs?? also - just to throw this in - Does the colour of the crimp - affect BS7671 - Correct identification / colour of conductors?? if so do i then need to use insulation tape.. I await your answers with baited breath.......

 

[Big_Spark]

Jenki, the only accepted method for jointing cores inside a consumer unit or distribution board is crimp terminals/through crimps. If you used connectors the board would be a bigger pigs ear than it will be anyway.

Ideally you should use the correct crimp for the correct cable size, and use a proper ratchet crimping tool for this..not one of those cheap and nasty DIY jobs..these connections must be tight and electrically sound, a ratchet will give equal force all over the crimp on be consistant on all the crimps regardless of size.

I would point out that crimps should only be a last resort, where-ever possible you should try to make as many reach the terminals as possible, but they should not be pulled tight to achieve this.

 

[jenki]

Jenki, the only accepted method for jointing cores inside a consumer unit or distribution board is crimp terminals/through crimps.

Thanks for the info - , just curious - is this method mentioned in the regs / on-site guide been looking for it and could'nt find it??

 

[Big_Spark]

Thanks for the info - , just curious - is this method mentioned in the regs / on-site guide been looking for it and could'nt find it??

No, this kind of thing is not mentioned, normally you would go out of your way to avoid such circumstances as it is not good practice, and you would certainly not do it on a new installation..I would be horrified to find it in a newly installed DB or CU in a new installation.

As you don't have many circuits, have you considered lifting the floor above and using JB's to extend the cables so that crimps are not required?

This would be far more acceptable, a preferable solution and would make life easier in the consumer unit?

 

[ban-all-sheds]

Why lift the floor? If JB's are acceptable, why not put them on the wall where the CU is now, and reposition the CU, if repositioning is an option.

If you do use crimps, and you are concerned about insulation, RS sell a range which have quite a long overlap of heat-shrink insulation integral to the crimps:

They're made by Raychem, so no doubt available from other fine suppliers.


Also, FWL - I've wondered before about using rail mounted through terminals like these when needing to extend several cables:

You can get them capable of handling any size cables and currents you'll find in a house, and they have terminals where plates bear down on the conductors, so IMHO superior to ordinary JBs. You could easily mount a length of DIN rail in an ABS box on the wall.

Would they be acceptable?

 

[securespark]

Ok, OK.

Put me out of my misery - I need a glossary for all abbreviations (I know I've been guilty of using a few of my own) starting with IMHO..

Cheers!

 

[Big_Spark]

Ban, using DIN rail mounted terminals would be a great way to go, although very expensive by the time you add all the costs.

I would not buy ANYTHING from RS, unless it was unavailable elswhere, as the prices they charge make Dick Turpin look innocent of all charges!!

Ban, he cannot get JB's on the wall, re-read his post.

 

[ban-all-sheds]

Ok, OK.

Put me out of my misery - I need a glossary for all abbreviations (I know I've been guilty of using a few of my own) starting with IMHO..

Cheers!

In my humble opinion.

IMO - In my opinion
AFAIK - As far as I know
BTW - By the way
NIFOC - Naked in front of computer.

The list is endless-ish.

SWALK. Ooh - no - not that one

 

[ban-all-sheds]

Ban, using DIN rail mounted terminals would be a great way to go, although very expensive by the time you add all the costs.

They're not that bad..

I would not buy ANYTHING from RS, unless it was unavailable elswhere, as the prices they charge make Dick Turpin look innocent of all charges!!

Indeed. Handy source of pictures though. And to be honest, they are competitive in some areas.

Ban, he cannot get JB's on the wall, re-read his post.

Re-read mine - he'd have to move the CU, and put the JBs where the CU is now.

 

[Big_Spark]

Ban, he cannot get JB's on the wall, re-read his post.

Re-read mine - he'd have to move the CU, and put the JBs where the CU is now.

I really need to get my glasses checked!! Sorry fella

 

[il78]

Adaptable box & DIN connectors sounds good to me........

 

[securespark]

Ban

NIFOC!!! The mind boggles.....now I have an image of a large DIY store-hating bloke somewhere in Middle Earth (!) sitting in front of his PC (or Mac, I'm not being prejudiced!) with not a stitch on. Hmmmmm....

BTW, I don't blame you for your hatred, I do too. Especially the way they put up "Excellent Customer Service Award" Certificates behind the check-out, when you can't find anybody to ask a question, there's only one till open, and you can't get thro' on the dog, or if you do it's to an amoeba who knows sweet fa about dogsh*t, let alone DIY products...I have to use my local one sometimes, and everytime I go in the above is true. And everytime I collar the manager (a FF restaurant reject) and complain about the awful service. And the reply is always the same. "We are having seasonal staffing problems". Pah!!

I have to confess I am twitter & bisted about this particular topic because I worked for them in 1988, and they fired me for being unhelpful!!! Must be a first for *** (company name obliterated for legal reasons).

Anyway, enough rant. I can feel my aorta swelling as I write!!

 

[Big_Spark]

I had a good one today..I went to a local B&Q (Whetstone) to get some timber for a new fence around the field, and this idiot was trying to explain to this woman how to wire up...............................................................................







a Solar powered light!!!!!!!!!!!!!!!


I had to laugh..then carried on buying the timber

 

[AdamW]

I usually feel miffed coming out of some of those places, knowing that if only I had bought the bits on my last order to an internet retailer then I would have saved a load of money. They are good if you just need to get a few things or if you want to see a display. Although my local builder's merchants has the biggest bathroom showroom I have ever seen!

However, I had a good experience today. Walked into Homebase and asked about Hippo Bags (those "skip bags" that get picked up from your house) and not only did the bloke know what I meant and where they were, but I didn't get any funny looks for asking for such an oddly named product.

 

[securespark]

Adam

Didn't know you knew my missus!!