shower electrics

had 10.5kw electric shower for about a year now. recently starting smelling bad then blew the trip switch. is my cable to small, although i am sure it is the thickest you can get, or could it be sommit else ?

What is the fuse/mcb size ie 40 amp,50?

Is it protected with an RCD?
What blows?
What smells,trip, the isolater switch or the shower unit it's self?

Is the cable the same as electric cooker cable(if you have one),or bigger?
What is the distance from fuse board to the shower?

More information required

sorry! bit thick . what is RCD? cable same if not bigger than cooker. cable around 8 metres and its the pull switch that smells me thinks and that is very hot to touch after use. nothing really blew it was just the trip switch.
is it strange how it has been fine for a year now, then suddenly starts to go funny on me

notgotfoggyest said:

sorry! bit thick . what is RCD? cable same if not bigger than cooker. cable around 8 metres and its the pull switch that smells me thinks and that is very hot to touch after use. nothing really blew it was just the trip switch.
is it strange how it has been fine for a year now, then suddenly starts to go funny on me

Click to expand...

find out what size the cable is then come back. the RCD is usually twice as wide as the MCB and hasw a T or Test button. and what size os the MCB?

pull switch that smells me thinks and that is very hot to touch after use

Click to expand...

Try this for size:

1) Bad connection (or over-run contact) in pull switch gets b****y hot.

2) Plastic parts of switch burn and carbonize.

3) Carbon conducts electricity.

4) Carbonization spreads across to other side of switch and starts to carry current.

5) Switch gets even hotter.

6) Carbonization accelerates until --

7) Trip switch does it's job and prevents a fire.

Was the isolator switch installed at the same time as the shower?

If the shower was a replacement for a smaller one (say 7.5kw) ,it could be that your isolator switch is not the correct size and there fore not designed to take the current, that your 10.5kw shower would draw.
ie in the region of 45amps.

If you feel confident , first isolate shower supply at the cu.
Remove cover screws of the shower isolator ,are the switch terminal screws loose check
Remove the isolator switch ( making a note of what is connected to what),the current rating will me stamped on the switch in amps, if not 45 or above replace with a suitable new one,or if it looks damage in any way.

Check all cables make sure there is no signs of over heating,ie is the red or brown going black in colour ,is the plastic coating crumbling leaving bare copper showing.

This could mean the cable is undersized and might need to be replaced.
If the terminal screws were loose this could account for the problem as
felix suggested and remaking the cable could be all that is required.

However
I would suggest calling in an electrician to check things out .

cheers for your help everybody , discovered a bad connection due to the cable being disturbed during insulation being laid in loft wires were touching and melting, then smelling. all cables and switches were the correct sizes, but thanks again for confirming those