Can a new circuit be added to this old CU?

[Milleniumaire]

My elderly in-laws had an RCD tripping issue last week and it took two visits by a very expensive electrician and 5 hours work to identify two wall sockets in the utility room had been scorched and were causing the RCD to trip. It would appear that many years ago, a kitchen installer extended an existing socket to two others and used aluminium cable. One of the additional sockets is used for both the washing machine and dryer, which are regularly used at the same time, so it has been suggested that the load on that circuit is what is causing the problem.

Both sockets were replaced and the cable wires cleaned up and the RCD tripping appears to have been resolved. We have been warned to only use the washing machine and the dryer, one at a time to reduce the load and avoid the same thing happening again.

I am wondering if it would be possible to introduce an additional circuit into the CU, specifically for use by only the washing machine and dryer, thereby avoiding using the existing two sockets that have been installed using aluminium cable.

Here's a photo of the CU:

View media item 108820
As you can see, there isn't currently any space for a new MCB, but I did wonder if the existing double pole RCD could be replaced with one that doesn't take up two slots, allowing an additional MCB to be installed along side it? The photo isn't that clear, so to confirm, the RCD is at the far left of the CU. If this is possible, would it also be advisable to use a thicker cable? I guess the next size up would be 4mm, which seems like overkill.

 

[ericmark]

A new circuit needs to be registered, it cost too much to register work through the LABC, so only option is use a scheme member electrician. The CU already does not comply, as it has wrong MCB fitted, so a scheme member electrician should refuse the work unless a new consumer unit is fitted, he may be willing to stretch a point, and to help you out do some thing to help. However that is up to him, not people on a forum.

What happened in mothers house was they fitted a large MCB feeding a second consumer unit to power her kitchen, there are usually ways around the problem, but to work out how, needs a site inspection, not really some thing one can help with on a forum.

P.S. one can hardly blame the kitchen fitter, it was Ian Smith in South Africa who caused the temp move to aluminium cables. And this was around 1965, so also need to check for earths on lighting circuits. It was 1966 when the rules changed, to use lights without an earth before that date it was required that they were filament lamps, so can't use standard LED bulbs. OK being a bit pedantic there, but seems likely there may be more problems.

 

[Milleniumaire]

........The CU already does not comply, as it has wrong MCB fitted, so a scheme member electrician should refuse the work unless a new consumer unit is fitted, he may be willing to stretch a point, and to help you out do some thing to help. However that is up to him, not people on a forum.

The house is around 40 years old, so obviously an old CU that wouldn't meet todays specifications. I assume you are therefore saying that means no work can ever be done on this CU, so it would need to be replaced or worked around by adding a second CU.

 

[Taylortwocities]

Both sockets were replaced and the cable wires cleaned up and the RCD tripping appears to have been resolved. We have been warned to only use the washing machine and the dryer, one at a time to reduce the load and avoid the same thing happening again.

That is incorrect advice. An overload does not cause an RCD to trip. An RCD trips if there is an earth fault.
The MCB will trip if there is an overload. If the electrcician has installed reasonable quality sockets, and done the repair properly, then theres no reason for your parents not to use both appliances at the same time.

As above. There's no space for a new circuit to be added.

PS What cowboy crowbarred that extra MCB marked "BS3781" into the consumer unit? What does that supply?

 

[ericmark]

The house is around 40 years old, so obviously an old CU that wouldn't meet todays specifications. I assume you are therefore saying that means no work can ever be done on this CU, so it would need to be replaced or worked around by adding a second CU.

No it would be OK to work on it, but a consumer unit is a type tested distribution board, and the type testing means you can only fit items made by the same manufacturer as the board, and clearly by the manufacturer to be used in that board. There is clearly at least one MCB which does not seem to fit right, so seems likely that board is discontinued, and some one has found something to fit the board.

It is up to the guy doing the work, as to how much he will bend the rules.

 

[Taylortwocities]

and some one has found something to fit the board.

Someone has found something that doesn't fit the board!

 

[Milleniumaire]

That is incorrect advice. An overload does not cause an RCD to trip. An RCD trips if there is an earth fault.
The MCB will trip if there is an overload. If the electrcician has installed reasonable quality sockets, and done the repair properly, then theres no reason for your parents not to use both appliances at the same time.

As above. There's no space for a new circuit to be added.

PS What cowboy crowbarred that extra MCB marked "BS3781" into the consumer unit? What does that supply?

I have no idea who/when that MCB was fitted, or even what circuit it controls. It does look like a couple of additions have been made over the years as the one next to it, although branded Wylex, doesn't appear to be the same as the original MCB's.

When the electrician first visited, as well as the single socket with scorch marks and burnt wires, he found 3 cables connected to the MCB that had the fault, which was the 2nd MCB from the left. When he removed one of the cables, this stopped the RCD tripping and because he couldn't find anything that wasn't working in the kitchen, assumed the cable wasn't used! Within 10 minutes of him leaving I determined it must be for the garage as the electric doors no longer worked.

Unfortunately, the following day the RCD tripped again and couldn't be reset without turning off the 2nd MCB (kitchen sockets), which is when he spent another 3 hours testing and found the 2nd affected socket at the back of a cupboard, 40cm to the right of the original socket he had replaced. He told me he was going to simply remove the socket, connect up the cables and blank it, but he then installed a double socket for some reason, I think because he didn't have any blanking plates! Not much use at the back of a coat hanging cupboard!

At £92 + VAT per half hour and 5 hours work, it has been a VERY expensive repair!

 

[Murdochcat]

At £92 + VAT per half hour and 5 hours work, it has been a VERY expensive repair!

That's a complete rip off

over £1100 ?

 

[Taylortwocities]

That's a complete rip off

over £1100 ?

For Nuneaton, yes. But maybe its on a Red route, Kings Road, Chelsea

 

[Milleniumaire]

Yes, £1,104 for 5 hours work. A company called Able Group. We are in West Yorkshire. It was a same day call out as my elderly in-laws were without heating until the tripping issue was fixed. I was reasonably okay with the first bill of £441.60 for 2 hours work to fix the issue, but when it tripped again the following day..... Unfortunately for me, they were the 3rd electricians I called, with the first two local companies saying they were too busy.

 

[Harry Bloomfield]

It would appear that many years ago, a kitchen installer extended an existing socket to two others and used aluminium cable.

That would suggest it was done around the early 1970's, during the copper shortages. The problem with aluminium cable, was that it needed to be a size larger, and the alloy used to oxidise, causing poor, high resistance terminations.

The best solution, really, is to rip the aluminium cable out, and replace it all with copper. Personally, I would also make sure with such a double loading, that it became part of the ring, rather than a spur off the ring.

 

[Milleniumaire]

Thanks for the responses regarding the additional CU circuit, I have managed to get hold of an electrician so I will talk the options through with him.

Slightly off topic, but still related to the original issue, I finally got a chance to nip around to my in-laws and check what the expensive electrician from Able Group had done.

Here's the original single socket in the back of the cupboard that was found on the 2nd visit. It is pretty bad and thank goodness it didn't cause more damage:

20240920_174346.jpg

• Milleniumaire
• Monday at 1:34 PM

As he didn't have a junction box, he replaced this single socket with a double socket:

20240923_124939.jpg

• Milleniumaire
• Monday at 1:35 PM

However, as he explained, he didn't have a blanking plate, so instead has used a double socket cover. As you can see, within the socket, it isn't connected up:

20240923_125322.jpg

• Milleniumaire
• Monday at 1:35 PM

While "I" know this double socket is a "dummy", when the house is eventually sold it may be a little confusing for someone, so I'm tempted to replace the socket cover with a blanking plate myself.

I assume there isn't anything in the regulations about installing sockets that aren't connected up? It's not a safety issue, simply confusing if anyone tries to use it and given it is in the back of a cupboard used for hanging coats, possibly unlikely to be needed as a socket.

 

[Harry Bloomfield]

I was reasonably okay with the first bill of £441.60 for 2 hours work to fix the issue, but when it tripped again the following day.....

The second visit should have been free, if they failed to fix it, and the alloy ought to have been replaced..

 

[Harry Bloomfield]

While "I" know this double socket is a "dummy", when the house is eventually sold it may be a little confusing for someone, so I'm tempted to replace the socket cover with a blanking plate myself.

Nowt wrong with using a socket, as a blank. Just put a sticky label on it, with 'NOT IN USE' wrtten on it, or similar.

Able is a group, similar to Pimlico Plumbers. Making high charges, for quick fixes, relying upon urgent work for customers in desperate situations. You might have been better/ cheaper, moving them into a hotel for a few nights..

 

[Milleniumaire]

Nowt wrong with using a socket, as a blank. Just put a sticky label on it, with 'NOT IN USE' wrtten on it, or similar.

Able is a group, similar to Pimlico Plumbers. Making high charges, for quick fixes, relying upon urgent work for customers in desperate situations. You might have been better/ cheaper, moving them into a hotel for a few nights..

Unfortunately, they both have dementia and have carers visiting them three times a day, so moving them to a hotel wasn't possible and there was no way I was having them move in with us as that may have been the thin end of the wedge

To be fair, I was aware of the half hourly fee before they attended, but didn't expect it would take 5 hours over two visits to resolve the issue!