10.5kw shower wired in 10mm twin n earth on a 40A breaker a problem

[giddash]

Hi there,
I did wired 10.5kw shower with a 10mm cable on a 40A breaker for an old lady's bathroom.she recently got a builder in to do some tiling work and this guy thinks the wiring is wrong and that i should have use 45A breaker else the house will catch fire.I don't think his is right as there no way this could happen as I did test the breaker and it tripped in less than 5s but tought i should post this any way.

 

[electric will]

I'm still more interested in how the breaker ( assume mcb ) was tested

 

[tony mc]

No mention of RCD ?

 

[needasparks]

No mention of RCD ?

I think thats where the test is getting confused

 

[rich.250]

Obviously has equivalent test equipment to cb manufacturers....
Surely the design calcs should e done before install?? Or am I doing it wrong.... Lol

 

[Deleted member 26818]

It will probably turn out that it's an RCD and it's 40ms not 40A.
Doesn't matter though the ramp test came in under 5s so all's good.

 

[electric will]

5 seconds? Long time to be stood in a shower being electrocuted?

 

[cbw]

Your all bullies and trolls.

I would have no problem allowing this goulash chap to install my shower.

(But none of you know how much my wife is insurred for)

 

[bartkusal]

It seems like you on the limits here mate, all depends on reference method the cable is installed. There is no way it will catch a fire,using lower rating mcb you just increased protection for the cable, builder talking nonsense, if anything , if you increased mcb to 45A , you increase the risk of fire.
In any way I am not saying that your design is up to scratch without knowing details, and yes , not sure how you tested mcb?

 

[electric will]

Where's the op gone?

 

[Deleted member 26818]

He waited 5s, and yes you are right, it is a long time to stood in the shower getting electrocuted.

 

[Strima]

Where's the op gone?

Sorting his eyebrows out after trying to test the MCB... :lol:

 

[keniff]

I installed my 10.5kw on a 40amp mcb it's been fine for almost a year no trips. I had a 40amp lying around in the garage

 

[Deleted member 26818]

You wait untill the builder has a look at it.
He'll let you know if it's alright or not.

 

[keniff]

Yeah I better take it out and put it straight in to the 100amp mains fuse, that way it will disconnect under 5 s and stop any fires also it would be free to run! Builders ay!

 

[AP Electrical]

Don't understand the post at all, you do a basic install perform the required calculations to determine the correct cable size and breaker rating, once installed you tested circuit and issued paperwork and notified lbc, and then a tiler turns up and says you've done it wrong???.

Or happen you just guessed the cable size and breaker rating / didn't bother notifying the lbc and took the money?.

Whichever one it is it just doesn't sound like you know what your doing, if you did you'd check your books if you were that concerned, not post on a forum.