eto wrote:

I now notice that the cable gets warm (!); standard teenage daughter
shower (30 minutes...) gets it warm enough to bother me.
Full inspection of the cable, terminations etc shows no faults.

Warm does not actually indicate a fault - the rating of the cable is
dictated by how much current it can carry while its conductors remain
below 70 deg C. So even if if felt quite hot to the touch there is a
fair chance it is still in spec.

Having said that you will be near the limit.

Looking through your site gave me a lot of info, but 3 questions.
1) should I go to 10mm cable ?

You don't have to, but you could if you wanted (it ought to extend the
life of the cable a bit, and wil allow a bigger shower to be fitted in
future)

2) I have purchased a 30mA RCD - but after reading about 'nuisance
trips' etc should I go for bigger ?

What are you proposing to protect with the RCD?
(and no you are unlikely to want bigger unless you have some sort of
special situation like a TT earthing setup)

3) bathroom bonding is all ok, but one article recommends 'thickish'
cable for the secondary bonding line back to the board. Do I then
assume that the cable built-in earth wire ain't enough ?

No this is wrong - all you are trying to do is create an equipotential
zone.



--
Cheers,

John.

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