Hot shower switch and cable

[Stuartpaulpeters]

Hi,

We have a 9.5kw Triton shower. I have run a 10mm cable from the CU to an isolation switch outside the bathroom (12 meters) and a 16mm cable from isolation switch to the shower (further 3 meters). Using shower for 10 minutes then no problem, but longer than that and the 10mm cable gets very hot and the isolation switch also gets very hot and starts to smell chemically. Can anyone suggest a course of action to remedy this? Or should just ignore, seems to still work ok?

P.S. yes, I did say 10mm and then 16mm. I ran out of cable!
The cable is running along the top of the skirting in a bit of trunking all the way.

Cheers,

Stuart

 

[Steve]

Tighten up your terminations. I take its all new?

 

[RF Lighting]

It might be too late if your cable or switch has already been damaged by heat

 

[Taylortwocities]

Indeed, you'll need to strip back the cable to bright copper and probably replace the switch

Thats 40amps + so all terminations must be very good or they will fail.

Stuart, is that a new install? Did you notify the work

 

[mattysupra]

Indeed, you'll need to strip back the cable to bright copper and probably replace the switch

what happens to the cable if to much heat? what colour does it go? Side effects?

 

[Taylortwocities]

If the termination gets hot, the pvc sheath will melt and the heat will turn the copper black.

You'll never get a good connection on the copper so you need to cut it back.

 

[ban-all-sheds]

And then having done that and reconnected you should do an R1+R2 test, and insulation resistance, to confirm that all is well.

 

[Taylortwocities]

And compare the test results with the ones that you got when you tested and certified the original install.............

I guess you did notify the work as well??


- Works in a special location (bathroom)
- Was it a new circuit?

 

[Stuartpaulpeters]

Hi,

Thanks everyone.
I took the switch off and found that the supply blue neutral cable had melted at the end and the copper had gone off color. So I stripped it back and replaced the switch (which had also melted slightly around the neutral terminal). Its now fine and not getting hot at all.

I dont know what you mean by notify. Notify who?

Cheers,

Stu

 

[ban-all-sheds]

I dont know what you mean by notify. Notify who?

Your Borough Council's Building Control department.

Did you not know about this: //www.diynot.com/wiki/electrics:part_p and was your original installation work therefore unlawful?

 

[Stuartpaulpeters]

Nope, had no idea about it. So, yes, I guess it was/is.

 

[ban-all-sheds]

Good luck when you come to sell the house....

 

[Stuartpaulpeters]

So, do I just call them up now and get them to come round and check it?

 

[FingRinal]

Surely your work involved replacing the cable with the same spec. and same route as the old one which suffered rodent or impact damage. In which case you don't need to notify it

 

[Stuartpaulpeters]

Nice one, Cheers