Shower Switch is getting warm

[james2006]

I have a 10.5kw shower setup on a 50 Amp MCB, a 30 mA RCD and 10 mm2 wire. The problem is that the switch (which is located outside the bathroom) is getting warm when the showever is in use (especially after a shower of around 15minutes or longer).

The switch is rated as 45A (its a coooker style switch).

I understad that the shower is pulling around 46Amps at 230V. Therefore is this what is causing the switch to heat up (ie the showever exceeds the switch rating?

Does anyone know where to get a 50A swith from (I have only seen pull cord 50 A switches which I do not want to use)?

Or will I need to down grade the shower to say a 9.5Kw?

Or could the switch warming be solved another way.


cheers

 

[JohnD]

Might possibly be a loose wire in a terminal inside the switch; might be an old switch and worn.

As it is carrying a lot of current it wil generate a little heat, but it shouldn't be actutally hot, or scorched, or smoking, or smell of burning.

 

[james2006]

Thanks for the reply.

The switch is new so I will check that there are no loose wires.

The plastic on the oustide of the switch is just getting warm - there is not burning etc.

However If you feel the back on the switch after the shower has been (eg the bit of the switch where the wires are connected and normal sits in the wall) - this is actually hot - is this a problem??

 

[JohnD]

I can't feel it from here but there may be someone along in a minute who knows how many degrees temp rise is reasonable.

 

[fazed]

50A Pull switches available below...if it's any help!
http://www.tlc-direct.co.uk/Main_In...hite_Contactum_Index/Pull_Cord_B_2/index.html

Also, FWIW, calculating at 240v, rather than 230v. 10500/240 = 43.75A load.

 

[james2006]

I have checked the wires to the switch and can not find any loose connections.

However I have noticed that the wires coming into the switch are getting warm. But given that I thought 10mm2 wire is good for 50A+ loads and the RCD has never tripped (its a 50A RCD) I am asuming that the wire is not being overloaded.

Where the wire is covered by the core inculation and the outer insulation you can not feel any warming - it just appears to be by the switch where the insulation has been removed.

Any further thoughts on whether this sounds ok?

 

[plugwash]

personally i'm thinking possiblly a dodgy switch.

crabtree do a 50A rated wall switch iirc. if you can find a wholesaler that stocks crabtree i imagine they could get one for you.