6mm or 10mm to an electric shower ?

[jonthesparks]

had a job last week ,the company i work for use a contractor now and again for jobs we dont have time to get to . the deal was they would run in a supply for an electric shower up to the isolator and when we are ready we would come in and remove bath , install shower cubicle and shower . after opening the isolator i found they had wired it in 6mm T&E , considering the run from the cu is about 8m and then from isolator to shower will be about another 7 m i decided to rewire in 10 mm because personally i feel that although 6mm can carry up to 38 amps showers should be wired in 10mm which can take up to 52A when run in trunking . just wanted to know if anyone else feels that wiring in 6mm is an easy option which should not be accpeted or is it acceptable just because its whithin the regs figures ?

 

[simpson93]

well theres nothing wrong with it some people prefer doing things diffrently, for instance 1mil on lighting aposed to 1.5

 

[tony mc]

What were they told to install and what size shower ?

 

[telectrix]

nothing wrong with 6mm as long as its ccc, dependent of installation method, is not exceeded and it is adequately protected by OCD.

 

[jonthesparks]

the size of shower is up to me , something i forgot to mention is they fed the cicuit off a 40A breaker , which i know is easier to change the mcb than to rewire

 

[Octopus]

I put the choice of cable in the hands of the client, i.e. if 6mm is OK, I'll also offer the 10mm as an "upgrade" cost as its not normally much. Most go with the 10mm option.

 

[leckyant]

jonthesparks
You can do what you want,as long as it complies too the current IET wiring regulations

 

[clicon357]

There was a thread on similar the other day:

http://www.electriciansforums.net/e...rum/45042-8-5-kw-shower-6mm-tripping-mcb.html

Basically it will come down to the installation method for the cable IMO. Table 4D5 in the regs gives the current carrying capacities for twin and earth. Clipped Direct will give the best capacity as heat can dissipate more easily. As the table shows the capacities vary according to how the cable is installed. Taking it a step further there's all the de-rating factors to go in to. You then need to look at your voltage drop (Appendix 6 in the OSG).

 

[kamkam]

Just to the math
Ib>In>Iz
volt drop
Installation method
= correctly installed.

 

[SPARTYKUS]

You're forgetting in free air on tray. Cracking CCC with that

 

[clicon357]

You're forgetting in free air on tray. Cracking CCC with that

Or a catenary in the depths of winter! Wasn't forgetting trays etc it just wasn't on the table. Plastered direct into a wall isn't covered either is it?

 

[SPARTYKUS]

Im glad you realised I was being flippant! Yeah is it a shower in the snow dome lol