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Hello,
We live in an old stone built ground floor flat, built in the 1880s. Obviously the consumer unit and cabling has been updated a number of times over the years by previous owners. One being the Local Authority who owned the property back in the 1960s -70s.

We have lived here for 25 years and decided to have an electrical inspection carried out by a local Electrician. He is a good honest guy, fully trained and qualified and a member of quite a few registered bodies. His report has shown only a couple of problem areas that should be addressed. Separate circuits for appliances, swapping circuits to the protected side of the consumer unit, updating sockets and light switches. He says although our consumer unit is older and the cabling is older there is no need change it or renew at this time but it is something we should think about for the future. He did have limited knowledge with regard to our particular make/model of consumer unit. (Young guy probably not born when our consumer unit was installed)

Now, our plan is to sell up in the new year and realising that this would be a huge upheaval and at a hefty cost we have decided to not take on the task.
However, we have hit a juncture. Our plumbing is such that we have only ever had an Electric Shower.
We wish to maintain this arrangement but have decided to upgrade the shower to a more powerful 10.5Kw unit as the old 7.5Kw shower has packed in and as you have no doubt guessed, this will involve a cable and MCB upgrade.

Existing arrangement is; distance from consumer unit to shower, 25m. Cabling 6mm², under floor in solemn space and in plaster for the last 1m. 32amp MCB on RCD protected circuit.
Our fuse box is an Merlin Gerin, (photos attached).

My questions are; (bearing in mind we are not changing the consumer unit and only wish to change the cabling and MCB for this one circuit),
Q1, would the Merlin Gerin consumer unit be able to be upgraded with a modern Schneider Acti9 45 amp MCB in place of the Multi9 MCB.
Q2, Are our current Multi9 MCBs a C-curve? I'm not sure if the writing on the current MCBs indicate the Curve type.
Q3, Would the Schneider replacement MCBs need to be a C-Curve or B-Curve type in whichever case?
Q4, Rather than a consumer unit upgrade, could we actually just update all the MCBs in the consumer unit this way?
Q4, Should we upgrade all the MCBs to RCBOs instead. (Assuming there is room in the consumer unit for such an upgrade as I understand they are quite large in comparison).

From my internet of things investigation... I gather that Merlin Gerin are no longer in manufacture and subsequently that the proper replacement for Multi9 would be Schneider Acti9. Would this be the correct information?

Any good advice appreciated for 3 dirty children and a smelly wife... I've always been a clean guy...
 

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Schneider C60H RCBO's will fit that board. Merlin Gerin is now Schneider so only the colours and name changed on their switch gear.

Do not try and get the iC60H range to fit as they will not, only the C60H.

This way you will only need to install a new busbar rather than replace the whole board. I'd go full RCBO.

TBH that board is a very good make and I would be very reluctant to rip it out, unless required all your devices only need to be B type unless you have LED units with high inrush currents and the manufacturers recommend C type or if you have a decent sized welder in the garage.
 
Hi - just my opinion, but why not just replace like for like if you’re moving on?
For the upgrade it sounds like you would need a new cable from the CU to the uprated local isolator and then the new shower. But rather than mess about with the old Consumer Unit I’d probably put in a separate little board - Schneider do a 50A one (as you’ve mentioned them).
 
The odd thing that jumps out at me in the pictures is a relatively new 100a DP isolator which only has the live tail connected through it with the neutral being straight through a SP block. Why would anyone do that ?
 
The odd thing that jumps out at me in the pictures is a relatively new 100a DP isolator which only has the live tail connected through it with the neutral being straight through a SP block. Why would anyone do that ?

It's odd to fit a DP isolator when they are only connecting the line, but not unusual for a DNO to fit a single pole isolator in the line only.
Self connect meters with a built in isolator are single pole, and I've seen single pole isolators fitted in seperate enclosures occasionally.
 
What body the electrician belongs to is irrelevant and side tracking this thread. Posts removed.
Hi I don't understand your comment with regard to side tracking and am I to understand that you have removed my post?
I am a householder not an Electrician. I only mentioned the registered bodies because 100% of the Electricians that I looked up on the internet to do the job for me all advertised that they were registered with some organisation/body or other. Is this not the case for all Electricians? So are you saying that an Electrician registered with one of the following organisations is irrelevant?
BRE Certification Ltd
British Standards Institution
ELECSA Ltd
NAPIT Registration Ltd
NICEIC Group Ltd
SELECT (Scotland)
STROMA
Are there any Electricians you could recommend to me an ordinary family man in the street, not an Electrician, that I should hire to do the job who are not registered with an organisation? How would I know to trust them or their work?
I don't feel like taking a chance where electricity is concerned and would hope that I would get a good fully qualified Electrician. How would I know otherwise?

Thank you.
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None of your posts have been removed. I deemed the questioning of the bodies the electrician belongs to as being irrelevant to your issue.
 
Hi Dave OCD, the Isolator was fitted by British Gas when we had a new boiler installed. Can you see a problem with it and should I get them back to make amendments?
Thanks

The odd thing that jumps out at me in the pictures is a relatively new 100a DP isolator which only has the live tail connected through it with the neutral being straight through a SP block. Why would anyone do that ?
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None of your posts have been removed. I deemed the questioning of the bodies the electrician belongs to as being irrelevant to your issue.

Thanks for your reply westward10.

My apologies, I thought that you had removed my thread as you are a moderator and you said Posts Removed...
I was not questioning any bodies or their relevance. I merely mentioned that to highlight that in my opinion the local Electrician I asked to do the job for me had advertised these organisations. As it happens I checked the organisations for his registration and he was indeed an approved contractor and that gave me huge confidence in his abilities. As I said, I have no other way of ascertaining his credentials or reliability? Only a man in the street trying to get the best for my family...

Thanks...
 
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You haven't seen the removed posts, they were not pertinent to your question they would have sent it off track. None of your posts are a problem.
 
Hello,
He is a good honest guy, fully trained and qualified and a member of quite a few registered bodies.
He says although our consumer unit is older and the cabling is older there is no need change it or renew at this time but it is something we should think about for the future. He did have limited knowledge with regard to our particular make/model of consumer unit. (Young guy probably not born when our consumer unit was installed)

Existing arrangement is; distance from consumer unit to shower, 25m. Cabling 6mm², under floor in solemn space and in plaster for the last 1m. 32amp MCB on RCD protected circuit.
Our fuse box is an Merlin Gerin, (photos attached).

My questions are; (bearing in mind we are not changing the consumer unit and only wish to change the cabling and MCB for this one circuit),
Q1, would the Merlin Gerin consumer unit be able to be upgraded with a modern Schneider Acti9 45 amp MCB in place of the Multi9 MCB.
Q2, Are our current Multi9 MCBs a C-curve? I'm not sure if the writing on the current MCBs indicate the Curve type.
Q3, Would the Schneider replacement MCBs need to be a C-Curve or B-Curve type in whichever case?
Q4, Rather than a consumer unit upgrade, could we actually just update all the MCBs in the consumer unit this way?
Q4, Should we upgrade all the MCBs to RCBOs instead. (Assuming there is room in the consumer unit for such an upgrade as I understand they are quite large in comparison).

From my internet of things investigation... I gather that Merlin Gerin are no longer in manufacture and subsequently that the proper replacement for Multi9 would be Schneider Acti9. Would this be the correct information?


I would say there is no point replacing that consumer unit, short term or long term, it is a good quality board designed primarily for commercial/industrial use rather than domestic and any modern domestic CU would be a step backwards in my opinion.
The electrician not being familiar with that CU is may be due to them primarily working in the domestic sector rather than commercial or industrial.

Schneider have bought Merlin Gerin but are still manufacturing compatible protective devices. To bring it up to full compliance with current regulations you would need to change the non-RCD ways to RCBO's.
Whilst you can buy new compatible protective devices there is still a massive amount of the older type out there, mostly second hand or some new old stock.

The MCB's you have use an older labelling system than the current B, C, D, the but that says type 2 denotes the tripping curve.
 
I would say there is no point replacing that consumer unit, short term or long term, it is a good quality board designed primarily for commercial/industrial use rather than domestic and any modern domestic CU would be a step backwards in my opinion.
The electrician not being familiar with that CU is may be due to them primarily working in the domestic sector rather than commercial or industrial.

Schneider have bought Merlin Gerin but are still manufacturing compatible protective devices. To bring it up to full compliance with current regulations you would need to change the non-RCD ways to RCBO's.
Whilst you can buy new compatible protective devices there is still a massive amount of the older type out there, mostly second hand or some new old stock.

The MCB's you have use an older labelling system than the current B, C, D, the but that says type 2 denotes the tripping curve.

Thank you for your reply davesparks.

That sounds very good advice to me and I am delighted to hear that the CU is of good quality.
I think I will try to source the original MCBs from the internet and ask my Electrician to do the job for me. He quoted me a very reasonable £250 labour for the original work of running another cable to my kitchen, (both the oven and hob are on the same cable and have a dual outlet plate in the kitchen), he recommends that needs to be changed. Also to swap the cooker circuit to a lower amperage MCB and move it to the RCD protected ways... I guess I would try to source three original MCBs for him to fit. He would no doubt supply everything else, cables, sockets and light switches etc... Should I source a 45amp MCB for the shower and, am I right in thinking that I should get 2 x 30 amp MCBs for both separate oven and hob circuits?

Thank you...
 
He quoted me a very reasonable £250 labour for the original work of running another cable to my kitchen, (both the oven and hob are on the same cable and have a dual outlet plate in the kitchen), he recommends that needs to be changed.

Reasonable? I'd say its very unreasonable to take what sounds like a perfectly compliant and safe installation and carry out unnecessary work.
 
Thanks to all for your replies. Collectively I have had some great advice and gained some good knowledge with regards to my CU and the best course of action to take...
Thanks again and I wish you all a Merry Christmas and all the best for the New Year!
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Reasonable? I'd say its very unreasonable to take what sounds like a perfectly compliant and safe installation and carry out unnecessary work.
No, I will ask him to do only the remedial work. I'm sure he would be asking a lot more for a 4 bedroom, 1 sitting room, 1 bathroom, 1 cloakroom and a kitchen rewire with a new consumer unit. He said half a days labour of £250 for the remedial work and in my experience over the years with various Electricians in Edinburgh, that is a good price.
It will no doubt be extra for the shower that I don't mind paying. It will probably come in around £1000 that would be fine for me...
 
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