Discuss 10.5kw shower in the Electrical Forum area at ElectriciansForums.net

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:   American Electrical Advice Forum

Reaction score
28
Yesterday smelt a weird smell of burning/melted plastic in my bathroom after some looking about realised was the shower pull cord opened it to the the incoming live insulation completely melted an charred and the pull cord terminal melted shower was installed about 3/4 years ago but recent board change by council(council house), I've done a cable calc and l got a Ib of 45.65 A so next suitable breaker 50A and got a 10mm t&e, currently on 6mm 40A breaker. Would you reckon this was the reason it had melted or due to other reason?

Ps have isolated removed switch and stopped using shower
 
depends on the installation method. 6mm method C is 47A.
 
It is the wrong size cable for a 10.5kw shower, and yes it really should be 10mm on a 50A mcb. but none of that would have melted the terminal at the pull switch. :)
 
It is method C comes up threw void under airing cupboard then clipped in airing cupboard only bout 3 or 4 metre run but then still being 47 A wouldn't it be 50a breaker required? And 10mm
 
no, In < Iz. so that the MCB trips before the cable is overloaded. so if Izis 47A, then a MCB below 47A In is selected.
 
you get a little warmth at the terminations in the switch due to load current. this leads to expansion/contraction leading to a slightly loose connection after time. this then starts to arc, burn, and before you know it here comes fireman sam with his hose.
 
To be honest I doubt that a 6mm cable would have melted on a 45/50 amp supply unless the cable was sub standard and there have been cases of that.

More likely the switch had melted due to

a) Loose connection
b) Moisture getting into it and shorting
c) Cheap and nasty accessory ( same as cable could have been)
d) Old accessory that was rated 45amp and finally broke down
 
the 40A breaker will protect the 6mm from overload. start off by replacing the switch for a good quality one, crabtree round ones have good reports. then with the shower going full heat, clamp the L core in the DB and see what it's drawing. i'll be surprised if it's > 40A.
 
Change the switch to the 50amp Crabtree type, if the cable got damaged then you may have to replace, but you can IR test it ............if not damaged then just replace the switch.
 
It did get damaged, so no need to upgrade cable or breaker? And I was guna replace it with cooker type switch in airing cupboard and don't have the equipment to test only a apprentice
 

Reply to 10.5kw shower in the Electrical Forum area at ElectriciansForums.net

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

Electrical Forum

Welcome to the Electrical Forum at ElectriciansForums.net. The friendliest electrical forum online. General electrical questions and answers can be found in the electrical forum.
This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock