Consumer units Help

[Chris27001]

Can you connect 2 consumer units together, to accommodate the 24 circuits (due to several extensions over the years) running around my house. I have been told the existing unit is overloaded (space wise, some MCB's are doubled up)

I do not have the space (height wise) to fit a twin unit, so want to connect a 16 way unit to say a 14 way unit! Can this be done directy from the existing CU (how is this wired?)or do I have to have new 'tails' run from the meter?

 

[Taylortwocities]

With respect, you don't wire it. You should get a registered electrician to sort it out for you.
This work must be notified to the local authority and your question suggests that you do not have skills to do it and test it properly yourself.

Have a look here: //www.diynot.com/wiki/electrics:part_p:diy_electrical_work_and_the_law
and then

Get someone at www.competentperson.co.uk to help you out.

 

[Chri5]

The meter to CU cable would need to be terminated on a Henley block and from there 2 sets of tails are run to CU1 and CU2.

Most domestic supplies are single phase 65 or 100 amp head fused, 24 circuits seems a lot for a property. I'd ask the spark to do some load cals considering diversity to confirm the design is acceptable.

Then there's the 17th edition work required to bring your house up to the new standard that applied since July 2008.

Circuits will require RCD or RCBO protection, tails 25mm, main earth 16mm, earth bonding of gas and water.

Then the whole installation requires testing and certification,

As To2C mentions this is well outside DIY scope and must be done by someone with the correct skill and scheme membership.
Once done the work does add value, in as much as a 17th ed cert on a property with 24 circuits would be a near essential requisite for a property sale.

 

[Chris27001]

Thanks for that guys

I will now get another 'competent' sparks to, quote the job! and if does not know about a 'henley block' I'll get another!

The last one said I cant have two CU's in the same place and would have to have a twin CU in a new location!

 

[Taylortwocities]

You could probably have one in the existing location and another somewhere else.
Dont forget the circuits would have to be extended and moved.

Anyone on the competent person register will know about Henley blocks

 

[flameport]

If you do have 2 separate units, you should also have a separate isolator, which will cover the whole installation (i.e. both consumer units).

Really though, 24 circuits is far too many for one house.
How many rooms does this house have?

 

[securespark]

24 circuits is far too many for one house.

Is it?

I do not have a picture unfortunately, but I went to a house last month fed via a 3 phase board with 40-odd ways.

It was a large house.

Having said that, I have also seen smaller houses with many circuits. The one I remember was a house with a 20A radial for each room bar the kitchen & utility, which had a 32A radial each. Lighting circuits were wired with two rooms on each breaker, one up & one down.

There were also two showers, one cooker circuit & one hob circuit, one immersion, outside lighting & power & garage circuits.

That was 22 circuits.

 

[RF Lighting]

From a domestic property I am currently working in.

DB 2 of 3

 

[ricicle]

That must be some domestic install. Why so many circuits ? - if it requires that many for loading in a house then some of those circuits must be a long way from the dis-board.

 

[wingcoax]

RF That looks suspiciously like a commercial installation, I have done several larger installations but they were in sub-stations.

 

[flameport]

.. 24 circuits (due to several extensions over the years)

From the original post, it sounded as if the large number of circuits was a result of the extensions to the property, rather than being designed with that many circuits to start with.

Don't look here:

Wylex 40 way Quad RCD consumer unit

• flameport
• 12 Apr 2009
• 1

 

[RF Lighting]

RF That looks suspiciously like a commercial installation, I have done several larger installations but they were in sub-stations.

Why would I say it was in a domestic if it wasn't?

I've done loads of boards bigger than this on commercial jobs, but this is my record for a domestic.

There are loads of circuits for a few reasons.

Circuit length plays a part but was not the only consideration. 314.1 was one of the reasons, mainly the reduction of inconvenience, and the possibility of an accumulation of conductor currents due to lots of gadgets with filters etc.

Hopefully this should help.

Don't bother mentioning the missing blanks or the 'locking off'

 

[electronicsuk]

Looks like the customer has deep pockets

 

[VanSolo]

Wouldn't like to pay for that lot! I've changed a few three phase dbs since the seventeenth came out and the customers jaws have hit the floor.

 

[nozspark]

Love your lock out (5 - L1 & L2)

Also a "Secret corridor",,,, what goes on there