10.8kW shower cable size

[IQ Electrical]

And as i said il stand corrected, of which i do... having thoughts regarding a shower it does have thermal fusing within too as a back-up but yes as long as cable does not underate mcb then il also agree, my prehistoric teachings only included loads with their own protection for overloads but regs change so much im bound to miss the odd change.... viva la 15th edition

It's not exactly a widely known caveat and crops up quite often on forums, it just doesn't 'feel' right even though it complies....

 

[Deleted member 9648]

I suspect this is the reason why we can spur from a ring in 2'5mm cable fused at 32a......effectively the spur is limited to a load of 26a under normal circumstances.

 

[IQ Electrical]

I suspect this is the reason why we can spur from a ring in 2'5mm cable fused at 32a......effectively the spur is limited to a load of 26a under normal circumstances.

Yes, 0.5mm flex on a pendant etc etc.

 

[Guest111]

Is it just my maths or does anyone else get a figure a tad bigger than 47A for 10,800 Kw as per OP?

 

[Deleted member 9648]

46.95 according to my calculator!.....


Edit......OOHH just read your post properly........46956.5a.......might have to go to 16mm.

 

[trev]

10.8kw @ 230v=46.9A
10.8kw @ 240v=45A mate.

 

[Guest111]

10.8kw @ 230v=46.9A
10.8kw @ 240v=45A mate.

Come on Trev read the post properly he said 10800 Kw not 10.8 Kw

 

[trev]

Phil I swear I just saw your bit about a fundamental error and I said "10800kw for starter"
No idea where the post has gone
Update
That ones in the arms Dammit

 

[needasparks]

Example of reg 433.3.1 (ii).. would be fitting a 2way board with 2 x 16a mcb's you could effectively feed board of an Henley block in 6mm tails regardless of how large the fuse up-stream was because it cant draw long term a load exceeding the value of both mcb's.

This is like what was know as the busbar rule, with the reverse fusing. As far as i know its still acceptable as long as the fault protection covers upstream supply. But its one of the old school methods and would not be concidered by most now.

 

[beaver74]

table 4d2 is still for T+e bs6004 and gives a value of 52A in trunking or am I missing something

 

[Darkwood]

This is like what was know as the busbar rule, with the reverse fusing. As far as i know its still acceptable as long as the fault protection covers upstream supply. But its one of the old school methods and would not be concidered by most now.

Still see it alot, have you tried getting 25mm tails into a 2way board lol, but yes im currently fitting isolators of a 200amp busbar with tails from 16mm to 70mm coming off it into switchfuses.. waste of copper and money otherwise.

 

[cbw]

Well.....Bottoms to you all, I have a 10.8Kw shower at home and I installed it on the 40A 10mm circuit..............................

Its fine!

No melted cables, no house fire.

HOWEVER>>>> Would I do this at a clients house Hmmmmm?

Can you imagine trying to install 16mm T+E into an MK shower isolator?????

 

[DSpark1]

I agree with what was stated on the IET Forum to you, which is that Clipped Direct (C) is by far and away the most common reference method in a domestic installation. Also, as said, the shower is a fixed load which cannot overload and so the protective device need only provide fault protection.

but that would mean there no insulation in the property, and most if not all new builds have insulation in them so i can't see how it would b ref method c

 

[drew35]

I was surprised to see the other day a shower isolator light switch! I couldn't find a shower isolator so a search in the loft above revealed a 16mm cable to a sub board, with a double pole contactor as the isolator, switched by a light switch on the outside of the bathroom. This was a recently installed 10.8kw shower carried out by a bathroom company. So there's your answer, 16mm cable, contactor, rewire, rebuild etc!

 

[Knobhead]

DS, if you’re that worried about it put a 16mm in. Two forums have advised you, but you seem unwilling / incapable of taking advise.
Do it your own way!