Joining 2 core house cable?

[JOEPRO]

For my car lift install, one of my consumer units will need to be relocated.

Whilst I'm not an elecchicken I wired the replacement consumer units myself some 20 years ago. These were plastic Wylex units to replace old wired fuse types.



Metal clad is now the standard so I am considering replacing both consumer units again myself but with correct metal clad type.

Or ideally maybe one large metal consumer unit which can take all connections but not the full width that the 2x take up at present.

Question:

If some of the existing wires are too short when relocating it is there a decent solution to use there to joint them in plain view? Aka the existing wires are already tight as seen above.

 

[Pigeon_Droppings2]

I'm no electrician but wonder if something like inline wago joiners might work. They're nice and small so could be hidden in a box maybe.

Just need to confirm they're allowed for joining ring mains I guess.

 

[MetalMonkey]

If the cables are long enough to make it inside the new C/U but you just need a couple of extra inches to terminate you could just use inline crimps and heatshrink to extend them inside the C/U.

If they are far too short then you could joint them in a maintenance free junction boxes, providing they are rated for it.
If you have several to do it will end up looking very messy, in which case you might be better off getting a large adaptable box/enclosure and making all your joints in that.
There is a readymade thing you can buy - The wiska 818 relocation box which is designed for the job and has DIN rail mounted connecters. They don't give them away though.

Shame the door track is where it is, otherwise you could just move it up a few inches.

 

[Mark 5]

For my car lift install, one of my consumer units will need to be relocated.

Whilst I'm not an elecchicken I wired the replacement consumer units myself some 20 years ago. These were plastic Wylex units to replace old wired fuse types.

View attachment 475698

Metal clad is now the standard so I am considering replacing both consumer units again myself but with correct metal clad type.

Or ideally maybe one large metal consumer unit which can take all connections but not the full width that the 2x take up at present.

Question:

If some of the existing wires are too short when relocating it is there a decent solution to use there to joint them in plain view? Aka the existing wires are already tight as seen above.

Gosh where to start, while metal clad is a standard it is not necessarily the must.

If you are going to replace CUs consider a RCBO installation.

You might want to tidy up existing cable runs, don't look to bad to me, rearrange them so your longest cables go to your new CU, those that are short consider using one of these.

 

[JOEPRO]

I am leaning towards one large consumer unit. Modern compliant metal clad unit with 18 or 20 ways.

If that replaces these 2x plastic consumer units and sits to the left then should be clear of where the lift post is going so ideal really. And maybe no need to splice the wires. I'll take more measurements later.

 

[Mark 5]

I am leaning towards one large consumer unit. Modern compliant metal clad unit with 18 or 20 ways.

If that replaces these 2x plastic consumer units and sits to the left then should be clear of where the lift post is going so ideal really. And maybe no need to splice the wires. I'll take more measurements later.

You should be able to get away with something like this or this.

You will need to check what brand/ protective devices will fit.

 

[Robotstar5]

Before you do anything it may worth investing in an EICR to check for any issues you are unaware of and while the sparky is there ask advice on best solution.

 

[JOEPRO]

Thanks all for replies so far- all very helpful.

Gosh where to start, while metal clad is a standard it is not necessarily the must.

If you are going to replace CUs consider a RCBO installation.

You might want to tidy up existing cable runs, don't look to bad to me, rearrange them so your longest cables go to your new CU, those that are short consider using one of these.

When I last upgraded my consumer units it was to go from an old wylex fuse wire setup.

At the time the new Wylex unit with MCBs was an important safety and usability upgrade. This included RCDs in many of the circuits. Having them separated like I have now means that if something trips it doesn't take out the whole house. So fridge etc more likely to be on.

Your mention of MCBOs is a good one and would offer me2x advantages here. The additional protection of overcurrent protection which RCD doesn't have is a good safety upgrade. And also that these could go in and act individually essentially within the enclosure. So allowing me to yield more MCBOs in the one consumer unit VS giving up double slots for RCDS.

So yes a large single, quality metal clad unit with one main switch and individual MCBOs are what I'll look into.

Like this I mean:

 

[JOEPRO]

This looks well sized for my needs and would leave 2 or 3 spare slots for expansion.

And it has surge protection

FuseBox F3021MZ 21 Way RCBO Consumer Unit + Surge Protection

Shop for the Fusebox F3021MZ 21 Way Main Switch Consumer Unit + integral type 2 Surge Protection Device. Consumer Unit World, the one-stop FuseBox shop.

consumerunitworld.co.uk

 

[dobbslc]

A couple of these up high with some 2x2" trunking underneath leading to a new DB.

Wago L60 Wiring Center - Less Connectors | Wago_Connectors (207-4301)

 

[brightspark]

This looks well sized for my needs and would leave 2 or 3 spare slots for expansion.

And it has surge protection

FuseBox F3021MZ 21 Way RCBO Consumer Unit + Surge Protection

Shop for the Fusebox F3021MZ 21 Way Main Switch Consumer Unit + integral type 2 Surge Protection Device. Consumer Unit World, the one-stop FuseBox shop.

consumerunitworld.co.uk

hope you have a fat wallet for 20 rcbo units on top of that price

 

[JOEPRO]

hope you have a fat wallet for 20 rcbo units on top of that price

Yes that's true but I don't mind investing in a good unit especially if it increases safety.

Caveat being that I will likely encounter some issues with the RCBOs if they detect any existing faults the MCBs do not. I know the external lights can trip the odd time so not used any more. So that's one circuit I would disconnect and make safe before MCBO installation as they would likely pick that up and not switch on.

Besides the external light circuit the rest of my house electrical system is in great shape and never trips or anything.

 

[brightspark]

some good bargain prices on ebay for the fusebox rcbo

 

[Mark 5]

hope you have a fat wallet for 20 rcbo units on top of that price

I got a stonking deal from these people.

I've yet to install, ( unsure of a couple of things ) but a 20way +Surge + RCBOs + Glands and other bits and bobs, just over £270, some of the RCBOs were on special offer at the time, the CU was as well but I think I did all right.

 

[Mark 5]

Yes that's true but I don't mind investing in a good unit especially if it increases safety.

Caveat being that I will likely encounter some issues with the RCBOs if they detect any existing faults the MCBs do not. I know the external lights can trip the odd time so not used any more. So that's one circuit I would disconnect and make safe before MCBO installation as they would likely pick that up and not switch on.

Besides the external light circuit the rest of my house electrical system is in great shape and never trips or anything.

But that's a good thing don't you think, yes such faults may have you scrambling around and fault finding but once found and righted, you're away.

 

[JOEPRO]

A check of the measurements and a single consumer unit will work

Rough overlay



The lift will clear this by an inch or two so it will work.

The wire issue will also be OK now with the unit staying here. So no need to joint them.

From reading up I'll need to use an intumescent gasket along the top of the metal consumer unit enclosure to protect against fire spread.

 

[Mark 5]

A check of the measurements and a single consumer unit will work

Rough overlay

View attachment 475738

The lift will clear this by an inch or two so it will work.

The wire issue will also be OK now with the unit staying here. So no need to joint them.

From reading up I'll need to use an intumescent gasket along the top of the metal consumer unit enclosure to protect against fire spread.

So your meter tails, you're going to combine them into one Henley block, then L/N cable into your main switch and of course your Earth?

If not fitted, a DP isolator switch might be an idea

Meter tails and Earth will require a gland as they go inside new CU, you're final rings/circuits should be glanded or at least in trunking.

My understanding is if you gland no intumescent strip required, might be wrong on that.

EDIT scrub the combining of tails It's just one CU, doh but fit a DP isolator.

 

[MetalMonkey]

Before you do anything it may worth investing in an EICR to check for any issues you are unaware of and while the sparky is there ask advice on best solution.

^^ This is good advice – and nothing stops you conducting one yourself if you have access to the equipment.

Moving to a fully RCBO board is going to highlight any "interesting" wiring tricks that won't have necessarily shown up on an RCD board.
For example, borrowed neutrals, especially on hallway lights are a very common favourite.
It’s good to know what you are in to, before you pull the old one off the wall.

 

[JOEPRO]

^^ This is good advice – and nothing stops you conducting one yourself if you have access to the equipment.

Moving to a fully RCBO board is going to highlight any "interesting" wiring tricks that won't have necessarily shown up on an RCD board.
For example, borrowed neutrals, especially on hallway lights are a very common favourite.
It’s good to know what you are in to, before you pull the old one off the wall.

I was looking at buying an in calibration Megger 1700 series of my own so that during holiday period I could do dead circuit tests on my existing consumer unit to see if any if the circuits are showing up anything unusual before moving to full new RCBO Consumer unit in Feb or so.

Re testing yes I know I should get it done and I will get someome in next summer. Why summer? I know there are a couple of limited areas in my house where sockets are cracked or loose. Not things I have messed with personally but that are old issues I also haven't actively repaired and should. So really I'd like to spend the time myself to go around and make any defects I know about 100% right first. As I know someone testing the electrics will need access everywhere and no point bringing them in too early to point out bits I already know about.

Also at that point the inspection would include the latest consumer unit so take care of all in one hit so to speak.

I know the electrics in my house are in good condition otherwise. I have unearthed and repaired many past bodges by tradesmen along the way too! For example here is how I found my bathroom light wiring when renovating it:



Any work I have done has been tidy and using correct cables, earth sleeves and enclosures.