1940's Consumer Unit.

14 Jul 2012
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United Kingdom
I currently have an old 1940’s Consumer Unit with 3 fuses (30 Amps, 30 Amps and 5 Amps!) with no RCD's or MCB's and looking to upgrade.

My current set up is as follows:

30 amps: Downstairs Sockets (Front room, Living room and kitchen inc. Cooker.)

30 amps: Upstairs Sockets (Front Bedroom and Back Bedroom.)

5 amps: Upstairs and Downstairs Lighting Circuits.

In the near future, I would like the following in each MCB:

1. Front Room Double Socket.

2. Living Room Double Socket, Kitchen Double Socket (1), Kitchen Double Socket (2), Cooker Switch, and another Double Socket for the Fridge and Freezer...... and a Switched Fused Unit for the Boiler.

3. Upstairs Lighting Circuit. (for 4 lights)

4. Downstairs Lighting Circuit. (for 6 lights)

I need to know what the difference between a Dual RCD Consumer Unit and a High Integrity RCD Unit? I thought all Consumer Units where the same as circuits will end up going into one!?

I truly believe that anyone is better than the one I currently have but which one to choose is confusing!

I may go with this one!

Any advice?

Thanks in advance.
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Your existing circuits will more than likely NOT lend themselves to being split up in the way you want them to be.

Likely, if you want things laid out like that, you'll have to do at least some rewiring.

Dual RCD has two RCD's each feeding a bank of MCB's.

HI boards have dual RCD's then one or more ways not fed via RCD.

Best off to start with an EICR.

If your fusebox is not wooden, it is likely 1950's at it's earliest.

If your fusebox is metal, it could be 1940's or younger or older even.
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If you have a 1940s fuse box, that would suggest 1940s wiring too!

Or is this a 1940s house, that was re-wired at some stage?
consumer units should be metal these days.

Although plastic would be much easier and cheaper for a DIY install.
you can't make a post like this without posting photos OP! Vintage wiring forever!
You will need an electrician to do this work for you and test it.

Paul - this is so not a job which you can do yourself - you are going to have to get an electrician, and therefore it makes sense to have him provide the CU.

You can tell him whether you want a dual RCD or an all-RCBO one, and you might possibly be able to tell him that you would prefer a top-end make to a budget cheapie, but going off and buying one yourself and expecting him to fit it for you would be foolish.
I have vague memory of the 1940's fuse box, it was wood, and had fuse holders which had provision to hold spare fuse wire. Seem to remember three or four fuses, the house had two 15A sockets one upstairs and one down stairs, and most power was from the lights, we had double adaptors in the light sockets to connect the iron to. Pre-war there was no 13A socket or ring main, this was developed during the war ready for the post war re-building program.

Post war the number of sockets more than doubled, instead on one in hall and one on landing we got a socket in every room, my dad's house (1954) had 5 sockets all 13A plus a special 15A socket dedicated for the immersion heater, cooker was solid fuel so just 3 fuses sockets, immersion heater and lights.

I think it was 1966 with 14th Edition when we went mad on earthing, and lights required earth wires. This is still causing problems today we still find the odd house without earth wires to lights, in real terms if wired before 1966 then house needs a re-wire, as likely there are rubber cables. It was also around this time when Ian Smith with the Rhodesia crisis and until 1974 there was a shortage of copper and we for a short time used aluminium cables, they were to put it mildly no good, so any house with aluminium cables also needs a re-wire.

By 1980 when my house was built we had even more sockets think I had 10? not sure now, and one extra fuse with a supply for the cooker.

Add another 10 years and the sockets were split into two circuits and also the lights were often split into two circuits. And add another 10 and we had moved to breakers instead of fuses.

2001 saw what we all at that time considered as the 17th Edition it had new BS7671:2001 number but still called the 16th Edition. There were many changes at this time and massive changes to how houses were wired, in 2008 we had another large change BS7671:2008 now called the 17th Edition, at this point the RCD became much more widely used. Since then there have been amendments with amendment 3 requiring fire resistant CU which in real terms means metal.

So step one is work out how old the wiring is?

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