Domestic shower submain

[ChrisElectrical88]

We are installing a new shower, electric towel rail, light and fan in a bathroom. The existing mains board is a old wylex rewirable. Gas and water is 10mm bonding from the MET in the meter cupboard.

The existing mains board is litrelly inaccessiable at the back of a kitchen cupboard and would require multiple brand new units removing to even access, let alone getting a 10mm to for a 9.5kW shower and add RCd protection to existing circuits.

My idea is to run a submain around the outside of the building in SWA into a small cupboard next to the bathroom and have a dedicated board for the bathroom which i can then protect as needed.

However due to no access to where the supply enters the building to mount my switch fuse my only option is to put something in the meter cuoboard.

There is already a smart meter in the cupboard however not ebough room for a 63A switch fuse. There is however ebough room for a small 3 way unit, in which i plan to install a a 100A DP switch disconnector and 63A MCB. The max Zs reading or the B63 60898 will not be exceeded by the submain.

Can anyone see a issue with this or think ill get any comeback by the DNO? Cheers

 

[ChrisElectrical88]

Apologies for spelling, my phone is playing up.

 

[Rpa07]

By existing mains board inaccessible, do you mean that the consumer unit has been built over with kitchen cupboards?
If so you need to start shouting at someone.

 

[ChrisElectrical88]

By existing mains board inaccessible, do you mean that the consumer unit has been built over with kitchen cupboards?
If so you need to start shouting at someone.

Fuses are accessiable, can only get the them by removing the shelf and getting into the unit. Not practicle at all to start taking about and fitting henleys and switch fuse near.

 

[Deleted member 9648]

Sounds OK, although terminating your SWA may be a challenge if space is that tight.
Perhaps though you would be better ditching the electric shower and using a pumped unit, everything could then be fed off local circuits via RCD/FCU's

 

[ChrisElectrical88]

Its a 10mm 3c SWA, i can get it into the bottom of the meter cupboard if i take a brick out and then replace it afterwards, so shoukd get a nice enough swoop to the top right corner.

 

[Pete999]

We are installing a new shower, electric towel rail, light and fan in a bathroom. The existing mains board is a old wylex rewirable. Gas and water is 10mm bonding from the MET in the meter cupboard.

The existing mains board is litrelly inaccessiable at the back of a kitchen cupboard and would require multiple brand new units removing to even access, let alone getting a 10mm to for a 9.5kW shower and add RCd protection to existing circuits.

My idea is to run a submain around the outside of the building in SWA into a small cupboard next to the bathroom and have a dedicated board for the bathroom which i can then protect as needed.

However due to no access to where the supply enters the building to mount my switch fuse my only option is to put something in the meter cuoboard.

There is already a smart meter in the cupboard however not ebough room for a 63A switch fuse. There is however ebough room for a small 3 way unit, in which i plan to install a a 100A DP switch disconnector and 63A MCB. The max Zs reading or the B63 60898 will not be exceeded by the submain.

Can anyone see a issue with this or think ill get any comeback by the DNO? Cheers

We are installing a new shower, electric towel rail, light and fan in a bathroom. The existing mains board is a old wylex rewirable. Gas and water is 10mm bonding from the MET in the meter cupboard.

The existing mains board is litrelly inaccessiable at the back of a kitchen cupboard and would require multiple brand new units removing to even access, let alone getting a 10mm to for a 9.5kW shower and add RCd protection to existing circuits.

My idea is to run a submain around the outside of the building in SWA into a small cupboard next to the bathroom and have a dedicated board for the bathroom which i can then protect as needed.

However due to no access to where the supply enters the building to mount my switch fuse my only option is to put something in the meter cuoboard.

There is already a smart meter in the cupboard however not ebough room for a 63A switch fuse. There is however ebough room for a small 3 way unit, in which i plan to install a a 100A DP switch disconnector and 63A MCB. The max Zs reading or the B63 60898 will not be exceeded by the submain.

Can anyone see a issue with this or think ill get any comeback by the DNO? Cheers

The only thing I can say, is that if the existing CU is that inaccessible to the extent you describe, then that alone contravenes BS7671.

My first job would be to relocate the CU to a more accessible position for safety purposes, and ease of operation, as for running the cable around the outside of the building, probably wouldn't contravene any regs, but hardly a professional approach in my opinion.

 

[Deleted member 9648]

as for running the cable around the outside of the building, probably wouldn't contravene any regs, but hardly a professional approach in my opinion.

Sorry Pete....Probably wont contravene any regs? Which ones are you thinking it might?
I cant see any wrong at all with an SWA Distribution circuit on the outside of a building if it's properly installed

 

[ChrisElectrical88]

A black SWA tight to the soffets and edges wont even be noticed mate.

No money in the clients budget to start taking the kitchen apart and relocating existing board unfortunatly.

 

[Octopus]

Walk away then ..............................

or your next post may be about a customer who won't pay the bill.

 

[Deleted member 9648]

Why walk away when the OP has offered a perfectly feasible way of carrying out the customers request? We don't live in a perfect world.

 

[Rpa07]

Not one thought on the electrical hub of the property and they just built a kitchen around it costing who knows how many thousands . . . SOME PEOPLE!

 

[ChrisElectrical88]

I have no worries about been paid, the builder carrying out the bathroom will pay me even if they await payment. Good workibg relationship with them. My installation will be fully conpliant with BS7671 and an note will be put in the additional notes section about the existing installation. My biggest query about this post is putting a unit in a meter cupboard. I just wanted to provide some backgroubd with my question.

 

[Octopus]

so long as you are sure that the meter cupboard will accommodate the henley, the switch fuse, and extra cables ..........

 

['mr2'gd4u]

Correct current board situation will need sorting, 40a is sufficient and in certain situations the 10mm won't be protected against the 63a (57a rings a bell for 10mm swa?)

 

[Pete999]

Sorry Pete....Probably wont contravene any regs? Which ones are you thinking it might?
I cant see any wrong at all with an SWA Distribution circuit on the outside of a building if it's properly installed

I have no idea WP, that's why I said it probably wouldn't contravene any regs, and like you I can't see any reason why the SWA couldn't be installed on the exterior of the property
The OP never mentioned in his opening post that there were monetary constraints, to all intents and purposes it sounded to me as though it was his own place he was working on. As Murdoch said if there are money problems from the onset of the job, his next post could in all probability be how do I get my money from this customer, walk away, best option.

 

[Deleted member 9648]

Correct current board situation will need sorting, 40a is sufficient and in certain situations the 10mm won't be protected against the 63a (57a rings a bell for 10mm swa?)

Why will it need sorting if it has nothing to do with the work proposed? All that is needed is an advisory note on the EIC

 

[Deleted member 9648]

Correct current board situation will need sorting, 40a is sufficient and in certain situations the 10mm won't be protected against the 63a (57a rings a bell for 10mm swa?)

Why will it need sorting if it has nothing to do with the work proposed? All that is needed is an advisory note on the EIC

 

[Deleted member 9648]

This is ridiculous, are we suggesting we walk away from any potential job where the current fuseboard is less than ideal? You guys need a reality check.

 

['mr2'gd4u]

Why will it need sorting if it has nothing to do with the work proposed? All that is needed is an advisory note on the EIC

Was referring to requiring sorting if using that dB for shower, then referencing the incorrect fusing..

 

[Octopus]

This is ridiculous, are we suggesting we walk away from any potential job where the current fuseboard is less than ideal? You guys need a reality check.

Yup ............ when I'm busy ................I pick and choose.

 

[ChrisElectrical88]

Wont be touching exisiting dist board. 10mm SWA Clipped direct through no insulation.

 

[ChrisElectrical88]

Yup ............ when I'm busy ................I pick and choose.

Good relationship with buikder as said in previous post so no worries about money. Try to do all his work as we have a great workibg relationship

 

['mr2'gd4u]

Isn't there derating factors for in the sun?

 

[Dave OCD]

If there's any doubt about that a B50 would be adequate for this job I reckon.

 

[ChrisElectrical88]

Sorry, was putting the baby up. I agree dave that a 50 would be ok, however if an outdoor socket or sonething else is wanted in future then the supply is already there without having to cock about swapping supplys out. I am comfortable with my calculations that all derating factors have been taken into account. I do appreciate the questioning.

 

[Midwest]

I'm with Murdoch; that CU needs attention.

I've done council jobs, where a new shower room has been installed for someone with a disability etc, where the rest of the install is shocking, and a shower CU was installed from Henleys. Dunno how these council bods sleep at night.

 

[Rpa07]

This is ridiculous, are we suggesting we walk away from any potential job where the current fuseboard is less than ideal? You guys need a reality check.

I wouldn’t walk away - I’d just shout a lot! It’s my thing.

 

[PEG]

Go on...i can't be the only person,wondering if the builder,is the kitchen fitter...

 

[mhar]

My dno would object. Even for my youngest who is a dno sap I have had to put an ip rated enclosure adjacent to the meter cupboard to house switch fuses

 

[ChrisElectrical88]

Go on...i can't be the only person,wondering if the builder,is the kitchen fitter...

No it wasnt haha. They have done an awful job which is why this current builder is in for the bathroom.

 

[PEG]

No it wasnt haha. They have done an awful job which is why this current builder is in for the bathroom.

I bet they drew top dollar,and disappeared into the sunset,leaving others to receive all the abuse,and what cash is left...a very common scenario.

I have a list...a £60,000 kitchen re-furb,with concealed,badly supported push-fit waste,popping off and flooding under the £6,000 marble tiles... A £14,000 "luxury" bathroom,with similar,and extractor vent,hose and switch fitted...but no fan or wiring,and,what is in my experience,the worst soldering i have ever seen

Ooooh,and my very favourite,of last year...a large detached new-build bungalow,with the DPC at different levels,in the inner and outer leaf,but BOTH in the wrong position...i despair

 

[stevels4]

Mmmmm...meter cupboard...KMF....safe isolation....seal fairy again