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...

 

[Strima]

I'd s leave the bloody thing alone.

So would I but I like to give the customer other options.

 

[M-Ty]

If it were my house, I'd be perfectly happy to leave the electrical installation as it is, apart from either a like-for-like replacement of the faulty shower or a simple thermostatic mixer if the hot water system supports it, and consider whether the money saved would be more usefully spent on other things that could provide a greater reduction in risk, e.g. a shower mat, fire alarm system, a washing machine and tumble dryer that won't support a fire, a car with better NCAP rating, a non-slip path, a new house, etc.

 

[Iain Stewart]

If it were my house, I'd be perfectly happy to leave the electrical installation as it is, apart from either a like-for-like replacement of the faulty shower or a simple thermostatic mixer if the hot water system supports it, and consider whether the money saved would be more usefully spent on other things that could provide a greater reduction in risk, e.g. a shower mat, fire alarm system, a washing machine and tumble dryer that won't support a fire, a car with better NCAP rating, a non-slip path, a new house, etc.

Don't you think it would be a good idea to swap over the cooker circuit and shower circuit on the CU MCB's?
Thanks

 

[Iain Stewart]

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.

I have no idea where my competency would be... but I am no novice! I have updated my profile especially for you!

 

[Pete999]

I have no idea where my competency would be... but I am no novice! I have updated my profile especially for you!

Thanks for that Iain