DIY consumer unit install - yeer haaa!

[LiamPope]

Hellooo...

As some may be aware, I'm doing a renovation including a complete rewire and CU change. My CU and RCBOs etc etc came today so I will be making a start soon (not this weekend mind, as I need to finish the central heating for mr Gassafe to come on monday and commission).

Now please dont shoot me down in flames . Yes it's notified, I could go into ample detail about installation methods, diversity, predicted Zs', disconection times, the tests which will be/have already been carried out, answer BAS' 20 questions (OK 6 was it?), etc etc

However this is my first CU and I will probably ask a few questions of a practical nature that will seem competence-questioningly simple to the experienced on here! Hope that's OK?

Here's a couple:

1. More of an observation than a proper question really - my shiny new Hager RCBOs (from TLC) have black neutral pigtails. I was expecting blue. Am I right to be surprised? Is it old stock or are they still made black? Obviously they are unused and will be tested, so I guess it's not a major issue. I guess I need to sleeve the black to blue?

2. The supplied main live and neutral cables (main switch to RCDs etc etc) are very-multi-stranded, flex basically, with the ends sort of compressed together to form a rectangular 'spade' termination. The sleeving is pretty loose over the flex. Not a major disaster but will stop me creating a super-neat install with tube-map levels of cable straightness. I also need to change these about a little to create some unprotected ways (I've compromised on a dual RCD board with RCBOs in an unprotected way rather than full RCBOs). Is what I see used in neat looking installs for these main cables essentially just blue/brown singles? What CSA is generally used?

I'll no doubt have a few more in the near future. Any help appreciated. Cheers,

Liam

 

[streetlighter]

That flexible multi stranded cable is whats known as tri-rated

 

[Lectrician]

Dual split boards do have a mass of internal pre-wiring which gets in the way of making a neat job...

Hagar would not be my first choice, but far from the worst.

The MCB can be classed as an accessory, and as such is type tested with the CU - I would not bother sleeving it's N tail.

If your CU is not a 3 way spilt (just a dual), what are you going to do with the neutrals of the RCBO's or circuits you place in your 'created' unprotected area?

 

[LiamPope]

That flexible multi stranded cable is whats known as tri-rated

Oh that's what it is - I see. Is that why it gets away with looking smaller than the 25mm I'd expected to see in a 100A rated CU (its higher temp rating)? It may be 25 - I havent measured.


Thanks for the input, Lectrician. The Hager CU is intended to be reconfigured to allow the creation of unprotected ways. I had to buy the optional-extra little busbar section for the unprotected way neutrals. I'll have to shuffle the existing busbars around a little to accommodate this in the correct place, so I hope there's labels for the circuits, as the moulded-into-the-busbar-holder plastic numbering will no longer correspond to the circuit numbers

Liam

 

[securespark]

I would cut your losses and not burger about with the new board:

ask TLC nicely if they'll swap it for a high-integrity dual split board.

 

[LiamPope]

Hmmmm, well i bought what they call their 'flexible' 17th edition CU, which is advertised as being able to be setup to give unprotected ways for MCBs/RCBOs. Essentially the same thing as what other brands call a 'high integrity' board, I thought. And it is really - just didn't come pre-setup for high integrity ways, so I've had to slide the first RCD along, fit the extra neutral terminal bar, and I'm also a neutral link wire short . Available as another optional extra for a few quid

Anyway - another silly question:

3. Can I extend an RCBO functional earth lead? Solder/heat shrink?

Cheers,

Liam

 

[LiamPope]

It's a shame it's come to this...

Untitled

• LiamPope
• 12 May 2009
• 2

 

[ColJack]

they come about 500mm long to fit into industrial boards.. so why would you need to extend one? you cut it off to make it look neat and then had to move it didn't you?

 

[LiamPope]

Nope - honest! Measure twice, cut once and all that . Hager must be feeling the credit crunch - using up old reels of black for the neutrals and the functional earth really is about 200mm long, the tightarses!

I suppose I could swap my earth terminal bar over to the other side where the main switch and unprotected ways are, and move the neutral bars over the other way. Think that'd work - the neutral leads are much longer on these RCBOs.

Hmmmm I'd done a good few searches on here and never really heard a bad word about Hager, plus we use loads of it at work, so thought it'd be a good brand to go for, and a good price on TLC. However, this and a few other minor issues with this CU really aren't all that well thought out. Should I have gone for MK or Wylex perhaps, or, heaven forbid, looked somewhere other than TLC for someone else's CU?

Ah well it'll be reet. Cheers,

Liam

 

[LiamPope]

Well - since I finally achieved hot water, we decided to move in despite it still being a bit of a construction site. So it was time to go out with the old...

Untitled

• LiamPope
• 17 Aug 2009
• 1

And in with the new. Here's work in progress...

Untitled

• LiamPope
• 17 Aug 2009
• 1

Look OK? Still a few more circuits to wire in and a list of other things that need sorting...

1. Still using the old 16mm (I assume) tails, though main fuse is still 60A so not too big an issue I don't think.

2. CU earth is currently some 10mm left over from main bonding, so needs to be done in 16mm.

3. Stupid too short RCBO functional earths need extending.

4. Labelling etc, though not sure how well labels for the terminal bars will stick over the existing relief plastic numbering. Wish it had a flat panel like the Wylex they're touting in Screwfix.


I do have another little question: On pictures here and elsewhere, I've seen RCBO functional earths either sharing the earth terminal bar position with the circuit CPC, or in a seperate terminal dedicated to the functional earths. Any reason for going one way or the other?

Cheers,

Liam

 

[sparkyspike]

I've seen RCBO functional earths either sharing the earth terminal bar position with the circuit CPC, or in a seperate terminal dedicated to the functional earths. Any reason for going one way or the other?

I tend to put functional earth wires in the same terminal as the corresponding CPC. This makes it easier to remove one RCBO at a time. Doubt it makes much difference though.

 

[ColJack]

those blue neutrals look rather mangled.. what have you been doing to them?

couldn't you muster some 2 x 2 plastic trunking to fit above the board? or some large mini-trunking?

 

[LiamPope]

Do you mean the neutral link wires (I hope you dont think my circuit neutrals look mangled )? If so, those are tri-rated cable (apparently) with a loose fitting silicone sleeve. They dont hold a bend so are a bugger to get looking neat. Whatever you do do to them, the loose sleeving wrinkles up like slack socks. Might just have to live with it, unless you've any suggestions?

Liam

 

[sparkyspike]

Don't worry about it.

Any reason why the meter tails are in new colours, but the tails between the isolators are in old colours?

 

[LiamPope]

I had N-power out to swap the old mechanical meter, upgrade the meter tails to 25mm and fit an isolator (all free of charge ). He fit the old cu tails into the isolator and I'm currently still using those with the new CU.

Hmmm some trunking might have been nice for those cables at the top, although I'm still probably going to cupboard over the whole lot to cover the old cut out etc. If I dont (and maybe even if I do) I'll definately cover those cables up somehow. Still, doh that it's too late to simply use some mini trunking.

Liam