Running 10mm T&E externally?

[Brian Hunter]

I’ve done some labouring support work for sparks in the past (joiner by trade) and have a qualified spark installing an electric shower for me. To save him time I’m going to run the cable. Using 10mm. Walls and floors not easily accessible and shower is about 25m of wire from consumer unit. Easiest way is to go outside, up about 10 foot of wall then back in through the roof. If in galvanised trunking is this acceptable?

 

[Toneyz]

I fed my daughter’s studio (shed) in 10mm2 T&E.
I just clipped it to the rear wall of her house.

Does it double up as the washing line?

 

[Bellendian]

Is there any particular problem with using ho7 flex for the whole run from CU to isolator? It's got superior properties to T and E. I know people get wound up about using 'flex' for fixed wiring, but not sure why. Seems to be the norm on the continent, and none of this reduced cpc nonsense we have!
If I were to do the job, I'd use SWA, if only to avoid critisism from any following sparks about inappropriate use of flex...but is that actually the best solution?

 

[TJ Anderson]

none of this reduced cpc nonsense we have!

Hey, it's only got to be able to carry fault current for less than 0.1s in most cases. Most of the time they are actually well oversized!!

 

[TJ Anderson]

And there is nothing in BS7671 that I'm aware that would prevent using HO7 flex for the complete circuit.

 

[Brian Hunter]

Sparks walking the inca trail for the next 2.5 weeks and pretty uncontactable. Thanks. It’s a 7.0Kw shower unit. Was planning on putting the bit that sits outside in galvanised trunking.

Hey, it's only got to be able to carry fault current for less than 0.1s in most cases. Most of the time they are actually well oversized!!

thanks for the reply. Is it ok to run it externally in some form of trunking for about 10ft? The house has 80cm thick stone walls so pretty tricky to channel/go under floors etc.

 

[Toneyz]

And there is nothing in BS7671 that I'm aware that would prevent using HO7 flex for the complete circuit.

The only reg that comes to mind is adequately supported.

 

[DPG]

Galv seems a bit excessive for domestic, but depends on budget I suppose.

 

[Mark42]

Have you considered using NYY? I love the stuff: a bit dear but dead easy to install (unlike SWA) and it knocks spots off T&E.
You could do the whole run in NYY - no need to change cable types, and being solid core not stranded like HO7RN, it's easy to terminate at both ends.
I've just used some 5-core 16mm NYY for a sub-mains in my own house, where I'd have used SWA before. I'm converted! (Obviously in an area not liable to mechanical damage.)