Need help with new electric shower

[TallPaul22]

I had my house rewired 2 years ago and I asked the electrician to run in the wiring needed for an electric shower. The cable run length is about 20m and he has used 6mm T & E with a pull cord switch by the bathroom door. In the consumer unit he fitted a circuit breaker with NB150 B50 written on it. The main breaker is a CD284U 100A RCCB. My question is, what would be the maximum rated shower I could use for this installation. I am new to this forum so any help would very most useful

 

[Cremeegg]

Depends on the routing of the cable, its closeness to other cables and whether it goes through any insulation.

Why not get your electrician back to tell you as you wouldn't want to do it yourself and fall foul of Part P would you?.

See [url]www.competentperson.co.uk{\url]

Personally it I was asked to run the cable I'd have used 10mm2 as a minimum.

 

[TallPaul22]

The cable is run with other cables most of the way under floor boards etc. I would love to get my electrician back but it took him 10 weeks to rewire the house (it's only a 3 bed semi) and he started pinching my tools, so he isn't too welcome shall we say....

 

[Chri5]

Clipped direct (in other words surface clipped and run underfloor with no insulation on the cable) you JUST JUST JUST make 10.5kw

It really on the edge, could you be precise about the distance, confirm the cable route end to end as in 10m under open floor, 4m in stud wall with insulation etc..

Most decent showers seem to use 10.5kw, a few years back there were 7.5-8.5kw, so at the time the cable was adequate for it's intended use.

 

[TallPaul22]

I would say the cable is buried in a wall for 4m and then it is with other cables under floor boards and buried in walls right to the consumer unit. I have bought a Mira Sport Max 10.8Kw which I now think will be going on ebay. If i were to replace the wiring, what is the going rate for 10mm T&E and where would be the best place to buy it from

 

[Chri5]

I'd stick with the new unit and buy some cable.

About £100 for 50m drum, or £3.50 for a measured per metre length, some wholesalers will cut drums others won't.

Ebay might have half drums for sale where others have bought and only used some.

Thing is Part P means that either way (sparks does whole job or you run cable in) a electrician is required for certifying the installation.
No doubt you have the skill to run the cable in, but wet areas and juice are a firm Part P element.

Measure your exact root length and post back- because you haven't confirmed that the length is 20M in total, would you also clarify the cable grouping.

Are all cables in the same holes through the joists, or are they spread across a group of holes. There a difference between 5 x cable cable tied together and very loose bunching.

 

[TallPaul22]

I am an electrician, just not a domestic one and I can get it part P inspected. Thanks for your help Chri5. Some further research required I think.

 

[Chri5]

Naughty you not knowing the answer to your own post .

You should be perfectly aware of grouping factors, cable reference methods, voltage drop calcs and the like.

The answers are all in the 16th /17th editions.


No problem anyway, and stay around I'm sure you can help someone with a commercial question or two.

 

[Taylortwocities]

In the consumer unit he fitted a circuit breaker with NB150 B50 written on it.

I wouldn't be using that to protect 6mm cable!