UK Inspection Report, Electric Shower, Merlin Gerin and Schneider MCBs

[Iain Stewart]

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...

 

[Iain Stewart]

Answers in red.

What are you trying to achieve with these questions?

Hi davesparks, nothing in particular just a few things I was pondering out of interest that's all.
Anyway, I think I will leave this thread now as there seems nowhere else for it to go...
Thanks for your time, much appreciated.

All the best!

 

[westward10]

That is some odd pondering if you are none too conversant with electrical requirements.

 

[davesparks]

Hi davesparks, nothing in particular just a few things I was pondering out of interest that's all.
Anyway, I think I will leave this thread now as there seems nowhere else for it to go...
Thanks for your time, much appreciated.

All the best!

Maybe you could answer my questions first before you leave this thread? Particularly by what exactly you mean by RMC?

 

[Iain Stewart]

Maybe you could answer my questions first before you leave this thread? Particularly by what exactly you mean by RMC?

Hello again, yes sorry... I should have said old threaded 20mm black steel conduit. You were correct in your assumption of the terminology, Rigid Metal Conduit.

I would have normally said the old threaded type... I picked up the terminology from a friend of mine who has recently had some bright galvanised conduit surface mounted around their entire property, its a sort of 'trendy' thing they have commissioned to create an industrial look against old re-pointed brickwork. Actually looks good along side the reclaimed rustic timbers that they also utilised...

Thanks again davesparks

 

[davesparks]

Hello again, yes sorry... I should have said old threaded 20mm black steel conduit. You were correct in your assumption of the terminology, Rigid Metal Conduit.

I would have normally said the old threaded type... I picked up the terminology from a friend of mine who has recently had some bright galvanised conduit surface mounted around their entire property, its a sort of 'trendy' thing they have commissioned to create an industrial look against old re-pointed brickwork. Actually looks good along side the reclaimed rustic timbers that they also utilised...

Thanks again davesparks

As I said, I've not heard it described as 'rigid metal conduit' in the UK before.

Yes that 'industrial look' has become popular, prompting a lot of badly installed steel conduit to appear in high street shops and restaurants l.

 

[Iain Stewart]

As I said, I've not heard it described as 'rigid metal conduit' in the UK before.

Yes that 'industrial look' has become popular, prompting a lot of badly installed steel conduit to appear in high street shops and restaurants l.

Yes indeed a shop they own in London... Never paid much attention to the actual installation but looks good all the same.

Cheers and have a Happy one...

 

[richy3333]

This thread has turned very odd, or have I just consumed too much beer over the festive season ?

 

[Strima]

or have I just consumed too much beer over the festive season

No such thing, have a word with yourself and grab another beer.

 

[Iain Stewart]

Ok guys following your advice with sourcing used or new old stock and a chat with a retired Electrician, I have decided to have the CU converted to a double RCD unit. This is bearing in mind that the initial EICR recommended having the lighting put on an RCD circuit too.

We have found this RCCB on eBay, see photo, and have a photo of the CU with cover off. However, I have noticed that they look different despite the fact that the serial/product numbers on the RCCB's are the exact same. I cannot find another one like this and also there is a strange, non-switched, unit to the left of the RCCB with a L sticker on it. Is this a part of the RCCB or some other kind of device?

Thanks...

 

[Pete999]

Ok guys following your advice with sourcing used or new old stock and a chat with a retired Electrician, I have decided to have the CU converted to a double RCD unit. This is bearing in mind that the initial EICR recommended having the lighting put on an RCD circuit too.

We have found this RCCB on eBay, see photo, and have a photo of the CU with cover off. However, I have noticed that they look different despite the fact that the serial/product numbers on the RCCB's are the exact same. I cannot find another one like this and also there is a strange, non-switched, unit to the left of the RCCB with a L sticker on it. Is this a part of the RCCB or some other kind of device?

Thanks...

Rather than faffing with trying to alter your existing CU a better option would be to swap the entire CU, a bit more expensive, but far better in the grand scheme of things, good luck

 

[westward10]

As above fiddling with second hand parts to convert into something it isn't intended for is not recommended. Where are you going to fit this second rcd.

 

[Iain Stewart]

Rather than faffing with trying to alter your existing CU a better option would be to swap the entire CU, a bit more expensive, but far better in the grand scheme of things, good luck

Oh! Pete999, very controversial in terms of the earlier replies to this post... Your'e looking for a fight haha
[automerge]1578671718[/automerge]

As above fiddling with second hand parts to convert into something it isn't intended for is not recommended. Where are you going to fit this second rcd.

Two spare fuse ways to come out and a gap...
[automerge]1578671806[/automerge]

Oh! Pete999, very controversial in terms of the earlier replies to this post... Your'e looking for a fight haha
[automerge]1578671718[/automerge]

Two spare fuse ways to come out and a gap...

Why would it not be intended for? The same arrangement already exists on the other side!

 

[westward10]

Merlin Gerin never produced dual rcd boards so you will not be able to obtain the correct parts to ensure it complies to manufactures specifications.

 

[Pete999]

Merlin Gerin never produced dual rcd boards so you will not be able to obtain the correct parts to ensure it complies to manufactures specifications.

Not at all Iain, common sense rules. Can't access your profile, So it would be wrong of me to assess your competency to make a comment like that, and no, I'm not looking for an argument or a fight, looks like you are though, sorry for spelling your name incorrectly by the way.

 

[DPG]

Are you still intending moving out of this house soon? If so then forget fiddling about cobbling things together and leave it for the next homeowner. They may well get their own sparky to change things to how they want them to be. Probably RCBOs.