Shower Wiring

the amount of heating?
Heating of the cable, you mean? Possibly, although 'clipped direct', 6mm² is rated at 47A - so, if it's not very (thermally) 'insulatted', I wouldn't expect properly terminated 6mm² cable to get very hot with a 10.5kW shower.

Kind Regards, John
 
Especially with the cycling effects with shower loads I would expect the cable to not get anywhere near it's max. operating temperature.
 
the amount of heating?
Heating of the cable, you mean? Possibly, although 'clipped direct', 6mm² is rated at 47A - so, if it's not very (thermally) 'insulatted', I wouldn't expect properly terminated 6mm² cable to get very hot with a 10.5kW shower.

Kind Regards, John

Yeh i meant heating of the cable.

My brother has a 9.5kw shower wired in 6mm clipped direct, and both the cable and switch fasica on the isolator (wall mounted outside) get fairly warm after your typical 10-15min shower. I'd expect pushing that up to 10.5kw on 6mm would have made things run hotter still...

I guess it depends how "hot" we're talking, 40c vs 70c etc. 40c is enough to think "oh thats warm", but is likely perfectly fine. 70c is likely less fine.
 
Yeh i meant heating of the cable. My brother has a 9.5kw shower wired in 6mm clipped direct, and both the cable and switch fasica on the isolator (wall mounted outside) get fairly warm after your typical 10-15min shower. I'd expect pushing that up to 10.5kw on 6mm would have made things run hotter still... I guess it depends how "hot" we're talking, 40c vs 70c etc. 40c is enough to think "oh thats warm", but is likely perfectly fine. 70c is likely less fine.
Exactly. The current-carrying-capacity tables we're talking about relate to a maximum operating temperature of 70°C - very hot to the touch, but not enough to do any harm to the cable or its surroundings such as has been described.

The current taken by a 9.5kW shower is well below the 'maximum (70°C) CCC' of 6mm² cable clipped direct, so I wouldn't expect it to get very near to 70°C, particularly in 10-15 mins. However, it could well be 'pretty warm to the touch'!

Kind Regards, John
 
BTW, from a medical paper I happened across, an adult with normal blood circulation can stand 42C 'forever'.
With a skin temp of 97F (~36C) I guess anything higher than this feels warm.

Did you know if you dip your finger in water you can then dip it in molten solder very briefly? The water has to boil off before your finger is exposed to the solder temperature. Choose a finger that you don't particularly care about.:D
 
BTW, from a medical paper I happened across, an adult with normal blood circulation can stand 42C 'forever'.
It depends what you mean. I doubt that a human being could tolerate being submerged in water (other than their head!) at 42C 'forever'. Their enire body would gradually try to rise to the water temperature (which is too high for long-term survival), and I doubt that they could lose enough through breath alone to keep their core temperature at a 'safe' level.
With a skin temp of 97F (~36C) I guess anything higher than this feels warm.
It's a complex business. In terms of sensing ambient (air) temperature, humidity is a crucial factor. With very high humidity, temps above about 70°F feel 'warm'. With very low humidity, air doesn't start feeling warm until it gets to about 85°F, but the threshold for 'feeling warm' is never as high as body temperature. In terms of touching things, whether something feels hot or cold depends as much on its thermal conductivity as its temperature. A very good conductor (e.g. a bit of metal) at ambient temperature will feel cold to the touch, whereas a very poorly conductive material (e.g. expanded polystyrene foam) will feel warm at the same temperature.

Kind Regards, John
 
Its Defo 10mm2 that is one thing im sure oh.
That's good - but, as you will have seen (if you can see the wood for the trees in this thread!), even if it had been 6mm², that would almost certainly not, in itself, have been an explanation for the problem you had.

Kind Regards, John
 
Also remember that we don't know you from Adam, millarat, and we have had people here who have measured the width of T&E and decided that's what the size meant.

T&E which was 10mm wide would get very hot and bothered with a 10.5kW load....
 
Yeah, it's for small contact areas.

The kids who climb into abandoned refrigerators die of hyperthermia, not suffocation.
 

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