How to connect electric shower to old rewireable fuse board ??

[gb]

I have a problem, in that house has been rewired ?? sometime ago, but it still has rewirable fuses. The lighting circuits have been rewired, but with no earth run.

I need an electric shower, electric extract fan and electric light reposition.

Sparky says that he has to put in a new consumer unit, and thus rewire the house.

If the wiring is OK, it looks like the existing cable tails to the consumer box (they are all seperate single fused boxes) are not long enough to go to a new box.

Whats the best way forward, and the most cost effective.

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[george [dicegeorge]]

Does sparky want to rewire the whole house?

Or just put in a new consumer unit with an RCD for the shower, fan and
light,
in line with Part P and wet electrickery safety.
And maybe a new earth spike to go with it.

Why not get him to put in a little consumer unit with a few spare
sockets for future expansion of the wiring?

[g]

[Tim Watts]

On 26/05/10 20:07, gb wrote:
> I have a problem, in that house has been rewired ?? sometime ago, but it still has rewirable fuses. The lighting circuits have been rewired, but with no earth run.
>
> I need an electric shower, electric extract fan and electric light reposition.
>
> Sparky says that he has to put in a new consumer unit, and thus rewire the house.

He will have to check the main bonding is up to scratch, and in your
case probably any supplementary bonding in the bathroom, though the
latter is normally fairly easy to remedy and the former varied depending
on where things are. However, he is not obliged to bring your whole
house upto the 17th in order to add a circuit.

Therefore adding a shower circuit does not imply a CU change. The
shower will need 30mA/40mS RCD protection. So, provided your rewirable
fuse board is in a satisfactory condition:

a) Add a new fuse if the board will take it (space and board's max
current loading). Incorporate RCD in a box and position where convenient.

or

b) Add a new CU case, split the meter tails (Henley Block) to feed old
board and new CU. New CU has RCD protection. The CU itself needn't be
very expensive even for a good make and you don't need to have more than
one MCB at this stage.

However, the light and the fan are a different problem... At worst, the
only requirement would be to rewire that one circuit and include RCD
protection.

There is no requirement to upgrade any of the other circuits.

A third option would be that new CU, and add a second MCB for lighting
and rewire only the bathroom lights, leaving the rest alone. That should
not be any more disruptive as the cables are going the same way as the
shower circuit.

It would be a good idea to assess the state of the rest of the wiring at
that age, but if it is in good condition, it's time to get some more
quotes from other people. A full rewire is not an automatic presumption
here.

>
> If the wiring is OK, it looks like the existing cable tails to the consumer box (they are all seperate single fused boxes) are not long enough to go to a new box.

Henley block - a terminal block for meter tails solves this problem. In
fact I would have thought you would have one or two pairs of Henley
blocks with your setup anyway. Do any of those have spare ways?

MEM switch fuses by any chance? We had the same when I grew up. Take 2
out and you have virtually enough space for a new CU whilst leaving the
rest alone.

A new CU for just the shower and bathroom lighting would allow you to
rewire other circuits during decorating cycles in the future.

HTH

Tim

> Whats the best way forward, and the most cost effective.
>
>
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--
Tim Watts

Hung parliament? Rather have a hanged parliament.

[ARWadsworth]

"Tim Watts" <t...@dionic.net> wrote in message
news:htjtn4$5ar$1...@news.eternal-september.org...

I often have to add a new CU alongside an existing fusebox when doing
bathroom installs. It is usually easier to RCD the whole of the bathroom
electrics to save haveing to do the supplementary bonding

Cheers

Adam

[NT]

gb wrote:
> I have a problem, in that house has been rewired ?? sometime ago, but it still has rewirable fuses.

no problem

> The lighting circuits have been rewired, but with no earth run.

not ideal, but perfectly safe if you avoid metal light fittings

> I need an electric shower,

will go on its own new cct

> electric extract fan and electric light reposition.

can run safely on existing

> Sparky says that he has to put in a new consumer unit,

for what reason?

> and thus rewire the house.

again for what reason?

> If the wiring is OK, it looks like the existing cable tails to the consumer box (they are all seperate single fused boxes) are not long enough to go to a new box.
>
> Whats the best way forward, and the most cost effective.

Start by assessing the whole system, see whats ok and what isnt. Then
we cuold probably anwer that question

NT