shower power rating for consumer unit

[simon_1975]

Hello

Quick question for you experts!

I have a 60A wylex 'standard range' consumer unit which is approx 20 years old. An 8.5kW electric shower was fitted by one of the previous owners, complete with a pull-cord isolator, RCCB plus a 45A cartridge fuse. The main service fuse at the incoming mains is 100A

As these consumer units were not designed to take such a large load, I have disconnected the shower. Rather than fit a new CU, what kW rating would be acceptable for one of these old consumer units. Would 7.5kW be ok with a 32A mcb replacing the cartridge fuse?

Thanks in advance.....

 

[Adam_151]

240 x 32 = 7.68 Kw


(shower headline rateings are at 240v, and the voltage is actually still 240v, so it makes sense to use 240 instead of 230 in this calc.)

Some of of the wylex standard CUs had a separate way the other side of the isolator from the rest of them that could handle bigger circuits, I take it that this isn't the case with your board, and that brute force and ignorance has been used to stick the 45A circuit in a fuseway that has a max of 32A?

Also, with a board rated at a max of 60A, I'd be tempted to henley in a separate shower CU, rather than **** about with a poxy shower and eat away half the capacity of the board (and as its backed up by a 100A fuse...)
Or change the board totally

Oh, and part P notifiable by the way (whatever you do)