Some months back, my daughter's electric shower failed in a puff of smelly smoke. Mindful of part P I sourced an Identically rated replacement and fitted it. Fortunately the supply cable was long enough to be shortened back beyond the cooked bit. The electrical installation looked OK, sleeved earth, double pole isolator, twin+E PVC cable I just didn't think to check the circuit protection.
Shower performed OK, father pleased at not having to worry about suitable Christmas pressie until..... 2 months later circuit breaker starts tripping out occasionally. Parental panic mode on.... ingress of moisture, unseen junction box in wiring etc.
This is in London and 30 miles away so someone who knows more about horses than electricity was asked to identify the type and rating of the circuit breaker.
Ah! Shit! The load is 9.5kW, the cable is 6mm and the trip is 32amps. I suspect someone has fitted a more powerful shower without upgrading the supply.
Now the question for the team is... where do I go from here?
My electrical education stopped at the fifteenth edition which I see allows 40 amps for 6mm, load is 39.6 amps at 240v so a bit tight. There may be considerations of which I an unaware so please comment freely:-)
As yet I don't know anything about the consumer unit or the size of the feed tails or other loads. Is fitting a 40amp mcb likely to be practical? Meanwhile I think the shower is being used on a lower output.
The installation is typical of an Edwardian house, converted to shop, re-converted to flats, i.e.. bits all over:-(
regards