Fuse Boards and Consumer units for shower installations

[alphaomegalife]

Hi there guys, how are you doing? Can you solve the following problem?

As you can see in the following pictures there is a Wylex unit, that unit used to have rewirable fuses installed, however nowadays it uses mini-trips. As you can see it is at full capacity. Referencing to number 4 on figure 1 the 32 amp plugin mini-trip normally accommodates the use of an electric cooker, of which is not used; I ask can this cooker wiring which is no longer used be removed and the 32 amp mini-trip be replaced with a 45 amp plu in mini-trip.

In addition, the installation will also include 25 metres of 10.00mm twin and earth to connect a 9.5kw shower via a 45 amp double pole switch.

See the link below for the pics of my fuse board.

http://alphaomega2003.bravehost.com/Index.html

If the 32 amp plugin mini-trip cannot be replaced with a 45 amp version, where and how can a shower consumer unit be attached to this existing unit see figure 3. Please detail what is required and how the new apparatus will need to be installed.

 

[ban-all-sheds]

That fusebox does not have a large enough total rating to support a 45A circuit.

You can either replace the fusebox, or add a separate mini-CU with RCD and 45A MCB in it, supplied by connecting the meter tails to a splitter (Henley) block, and from there taking two sets of tails, one for the existing fusebox and one for the shower one.

Either approach will require you to pull the service fuse to isolate the supply, and although you will find info on doing that on this site, it's not something which DIY-ers should be encouraged to do.

So what you are encouraged to do is to get an electrician to do it for you. While he's there, get him to check the sizes of the tails - they look like they'll be too small.


Also, a few other comments re the fusebox wiring

1) Is it a trick of the light, or are the two ends of the ring in circuit 3 different sizes?

2) There's a loop of red wires at the top which look as though they are being crushed.

3) One or two places where the insulation has been cut back too far.

 

[alphaomegalife]

Hi there Ban all Sheds thanx for the post the ring circuit is all the same size cable it must have been the flash on my camera, what sized henley block do you recommend?

Will either of these do
http://www.screwfix.com/app/sfd/cat/pro.jsp?ts=25818&id=14850

http://www.screwfix.com/app/sfd/cat/pro.jsp?ts=26024&id=11497

Would you recommend the following CU for the shower
http://www.screwfix.com/app/sfd/cat/pro.jsp?ts=26024&id=69659

 

[ban-all-sheds]

Volex don't get a good press. It's hard to see how they can ****up the design of a Henley block though, but there may be people here with experience of them. Remember if you pick the single pole version, you'll need two of them.

Again with the CU, common wisdom is Volex are pants. If you want to buy from Screwfix they do Wylex units (better) and MK (better still), but you need to buy the components individually, i.e. enclosure, RCD & MCB.

If you're getting an electrician it might be easier to have him supply the bits - he'll be buying them for less than you'd pay, and even if he marks them up, if you deny him that markup he'll just load his labour charges to compensate, and could end up costing you more.