Consumer Unit 10 way henley block box

[george [dicegeorge]]

I want to install a new consumer unit lower than the old one, so need to extend the 12ish grey wires going out of it for a few feet, maybe more than that as there may be some ring mains.

There's a neat photo cu1.jpg I saved from uk-diy somewhere in February 2009, what exactly do i need to order? A plastic box with some kind of fixings and 24+ henley blokcs? Could I share the netral inputs, or must they come from the individual MCBs in the consumer unit?

Wylex 17th Edition Dual RCD Consumer Unit 10 Way & 10 x MCB

one of the consumer units i'm looking at.

[g]

[Tim Watts]

> is one of the consumer units i'm looking at.

Hi,

are DIN, not Henley just to be precise and the terminals are nominally individual (though some types can have a commoning bar fitted).

RS own brand are pretty OK for a decent price.

No you cannot ever common the neutrals, because it will really mess up if you have or later have some RCBOs in your new box which need the neutral fed through.

You can common the CPCs though.

HTH

Tim

[newshound]

That's a neat photo, but I'm a bit confused by it. Where are the incoming tails, and what's the big white strip at the top right corner of the lower box, the one with all the black wires?

[Tim Watts]

No mine - it's Andrew Gabriel's

The bottom box is a standard CU - the white blob is the neutral commoning bar. I just said you can't do that *after* the CU - but of course, the CU has to have one ;->

The bit the OP is interested in is the top box - used to extend the old wiring.

[ARWadsworth]

The incoming tails are via rear entry into the CU. You can see the neutral one going into the main switch.

The "big white strip" is the neutral bus bar of the CU.

[John Rumm]

The use of RCBOs in that CU nicely illustrates one of the reasons for not doing it prior to the CU as well (not to mention the confusion you might created for future maintainers!)

[Tim Watts]

prior?

[John Rumm]

looking from the circuits direction ;-)

(i.e. outside of the CU for the avoidance of doubt)

[Tim Watts]

Sorry John - lost me. (Might be the trauma of trying to use Southeastern trains this week or the kids all being ill)...

My "after" meaning the DIN box on top. I initially read your "prior" as meaning supply side of the CU - but you mean the same as me, don't you - the supply side?

Maybe we should say load side and supply side - it's getting like 2 blokes facing each other talking about left and right ;->>

[Tim Watts]

FFS my addled brain - ^^^ Load side

[newshound]

Doh.....need to reboot brain :-)

[Tim Watts]

I blame the weather!

[Andy Dingley]

Those Wylex units are quite nice. Look at TLC too, as they have it with 15 outgoing ways and two RCDs. They're very cheap for the MCBs too.

[John Rumm]

Yup I mean load side... You don't want to be commoning neutrals outside of the CU on the load side.

[george [dicegeorge]]

My brain should have deleted that line: of course it would have added confusion to common neutrals after the CU, and added danger, i want nice straight wires going up to the henley block-ish box. [g]

[John Rumm]

Yup, basically if you have as many wires into you junction boxes as you have out, and hence as many coming into the CU, then you should be fine. If you start trying to "optimise" things then they will likely bite you later!