Bad consumer unit wiring

[Multiplex]

We have a little problem. We live in a block of flats and the consumer units are all outside in a cabinet in the garage! The block of flats was built in 1976.

As we want to install an electric shower for the first time in our bathroom we've realised that somehow we're going to have to run a cable down to the consumer unit for the shower.

I would be interested if anyone here has any experience of doing this, as I'm not sure if it's even possible!

Simon.

 

[ban-all-sheds]

I would be interested if anyone here has any experience of doing this, as I'm not sure if it's even possible!

What route do all the existing cables take?

Would running the cable outside be easy?

How far is the garage from the flat??

 

[AdamW]

We have a little problem. We live in a block of flats and the consumer units are all outside in a cabinet in the garage! The block of flats was built in 1976.

Mmmmm, voltage drop-tastic.

Who was the willy who came up with that idea? I used to live in a 1930s mansion block in London and each apartment had its own fusebox in the kitchen.

 

[ban-all-sheds]

Just a thought - if they really are somwhere completely separate from the premises, do they meet the requirements for local isolation?

 

[plugwash]

id say 16mm or even 25mm if its long swa run on the outside of the building is your best bet

then take that to a metalclad isolator outside the bathroom and run in normal 10mm or 16mm twin and earth to the shower

 

[AdamW]

Seriously, are you sure that it is your CU that is in the garage? That really wouldn't make sense: running all of your circuits all the way from your garage to your flat, when they could do it with one cable and the CU in the flat instead.

And what happens if you need to reset a tripped MCB?

Are you sure there isn't a CU or fusebox in your flat somewhere?

 

[Multiplex]

Here's a picture:

Within the CUs the fuses are labelled: Immersion, Lights, Sockets, Spare.

Since we don't have the immersion heater connected anymore, is it possible to use the wiring for the new electric shower??

Simon.

 

[ban-all-sheds]

Here's a picture:

Jesus Christ...
How far is all that, roughly, from the furthest flat? Do the cables for one flat run through others?

Have you ever had problems with some antisocial git taking somebody elses fuse because one of his has blown?

Or theft of electricity?

Since we don't have the immersion heater connected anymore, is it possible to use the wiring for the new electric shower??

When you say "electric shower", if you mean an instant-heat one, and not an electric pump for a shower, then I'm afraid the answer is no, no chance.
I also fear that with your existing installation the way it is then you may have great difficulties in installing one at all, for reasons of capacity, space in the cupboard, rating of the supply and routing of cables.

 

[AdamW]

Is there a label on it saying "Maximum load"? I am just theorising here, but with only 4 fuses per CU wouldn't it be likely they are 60A max load, in which case fitting an electric shower would be a bad idea anyway.

 

[Big_Spark]

Looking at that intake I would say it was all put together b y a cowboy or amateur. Uou may be thinking Why?

Well look at the Earth's into the Head, there should be a single Earth leaving the head to an Earth Block, then Earths connected to the Main Bonding points and the individual Consumer units.

Don't have time to go into deep detail, but before you undertake any work of this nature you should contact the building Freeholder/Landlord before undertaking any work that means interference with communal areas and supplies.

 

[ban-all-sheds]

Another theory. Well, guesswork really.

If the flats are leasehold, and if that equipment is in a communal area, might it be the responsibility of the lessor to maintain it, just like he does communal stairways and/or lifts, lighting therein, the grounds if any, the roof, the building exterior etc etc? If there's a service charge that's what you're paying for.

In which case, maybe some concerted approach from all the residents to get him to sort that mess out might be a good idea. It does not conform to the regs, (and may not even have done so in 1976).

 

[Multiplex]

The flats are leasehold, but unfortunately (or fortunately?) the management of the flats is controlled by the flat owners as a collective. This means the bare minimum is spent on the upkeep, so no chance of getting it all rewired on any regultions basis.

In answer to ban-all-sheds, funnily enough living in south london you'd expect more people to open the cupboards and have a play around! we get lots of graffiti but for some reason the kids don't like to mess with the electrics.

What's the reason for not using the old wiring for the immersion heater? Will the wire not be thick enough? I would like to know because if I get an electrician that offers to do it, I can tell him not to on a sound basis.

Also, in the picture the four boxes in the bottom right contain 100A fuses. Two flats are connected to each fuse. Would that again cause problems for an electric shower?

I'm beginning to think I have a mess on my hands if I want to get an electric shower installed!

Simon

 

[plugwash]

immersion heaters are generally only 3KW and wired in 2.5mm cable there is no way you could put an electric shower on that

if the other flat on the same fuse as you (you are on speaking terms with them right) doesn't have an electric cooker or shower the 100A fuse should cover you both

here is what i think needs to be done to fit a shower
(and i doubt you will find a sparky willing to touch that cupboard withotu replaceing everything in it so you may have to do it yourself)

you should also make sure your main and supplimentry bonding are up to scratch but thats a seperate issue

it wasn't easy finding a supplier with what was needed but a bit of searching paid off (not many brands do type B rcbos and i really wouldn't reccomend the higher ratings of type C and you should generally not mix brands in a CU)

http://www.sparksdirect.co.uk/products/sections/consumer units/1.htm
http://www.sparksdirect.co.uk/products/sections/consumer units/2.htm

replace your CU with a metalclad 4 way
put the lights on a 6A mcb
put the sockets on a 32A type B rcbo
put the shower on a 40A or 45A rcbo depending on its rating

i would then run 10mm 3 core swa (10mm is good for just over 50m if its longer use 16mm) on the outside of the building to your flat terminate the SWA to a metalclad isolator near the bathroom and then run to the shower with 10mm twin and earth

 

[plugwash]

reaplaceing a CU shouldn't be that hard but there are a few things to watch out for

1: you need to pull the service fuse first take great care when doing this as some older units leave an exposed live when you pull the fuse

2: you may need to replace the tails from the meter to the CU if they won't reach the isolator position in the new CU if you are replaceing them use 25mm double insulated tails

3: the cables comign into your CU will be carrying a lot of current so make them off well

 

[ban-all-sheds]

immersion heaters are generally only 3KW and wired in 2.5mm cable there is no way you could put an electric shower on that

Glad you agree with me

if the other flat on the same fuse as you (you are on speaking terms with them right) doesn't have an electric cooker or shower the 100A fuse should cover you both

Let's hope they don't have either of those things....

here is what i think needs to be done to fit a shower
(and i doubt you will find a sparky willing to touch that cupboard withotu replaceing everything in it so you may have to do it yourself)

That will require the agreement of the other flat on the same fuse, as it'll have to be pulled.

you should also make sure your main and supplimentry bonding are up to scratch but thats a seperate issue

Judging by the photo, the main bonding needs investigation...

it wasn't easy finding a supplier with what was needed but a bit of searching paid off (not many brands do type B rcbos and i really wouldn't reccomend the higher ratings of type C and you should generally not mix brands in a CU)

http://www.sparksdirect.co.uk/products/sections/consumer units/1.htm
http://www.sparksdirect.co.uk/products/sections/consumer units/2.htm

replace your CU with a metalclad 4 way
put the lights on a 6A mcb
put the sockets on a 32A type B rcbo
put the shower on a 40A or 45A rcbo depending on its rating

There's also the physical space problem - from the photo it looks as if there is absolutely none spare - any replacement CU would have to be no bigger than the old one...

i would then run 10mm 3 core swa (10mm is good for just over 50m if its longer use 16mm) on the outside of the building to your flat terminate the SWA to a metalclad isolator near the bathroom and then run to the shower with 10mm twin and earth

I think I'd be tempted to use 16mm, put a simple fuseswitch in the cupboard and put a new CU in my actual flat.