well for a ten minute or shorter shower you could run that 40A shower on 2,5mm cable... But if my daughter were to visit (long shower territory) then cable damage may well ensue.

I presume you have not showered, or the data logger has been set up with far too long an integration period to catch it..

But there is a non-flippant point to this AMD is very much a roll of the dice -

1) the breaker total is wildly misleading and a serious over estimate,

2) Dividing the annual bill by the no of hours in a year misses the short duration  peaks and under estimates.

3) if you were to assume the OSG advice was right, then half the streets in the UK ought to be on fire...

Short of supplying the property via an instant acting trip there is no way to ensure any particular maximum demand  - a typical  DNO  fuse after all is capable of  supplying a load of twice its rating  for 15 mins or so several times a day with no ill effect.

Even the DNOs do not know that accurately  - in those cases where substation monitoring has been installed, it emerges that some transformers are running at up to twice capacity and others are almost unloaded.

Mike

well for a ten minute or shorter shower you could run that 40A shower on 2,5mm cable... But if my daughter were to visit (long shower territory) then cable damage may well ensue.

I presume you have not showered, or the data logger has been set up with far too long an integration period to catch it..

But there is a non-flippant point to this AMD is very much a roll of the dice -

1) the breaker total is wildly misleading and a serious over estimate,

2) Dividing the annual bill by the no of hours in a year misses the short duration  peaks and under estimates.

3) if you were to assume the OSG advice was right, then half the streets in the UK ought to be on fire...

Short of supplying the property via an instant acting trip there is no way to ensure any particular maximum demand  - a typical  DNO  fuse after all is capable of  supplying a load of twice its rating  for 15 mins or so several times a day with no ill effect.

Even the DNOs do not know that accurately  - in those cases where substation monitoring has been installed, it emerges that some transformers are running at up to twice capacity and others are almost unloaded.

Mike