fuse size.

[rymatom]

At the moment i have a 8.5kw shower and i am putting in a 8.7kw shower.
I have a 32A MCB wired to the 8.5kw shower. Will this be enough for the 8.7kw shower or will i need a 40A MCB?

 

[bernardgreen]

At the moment i have a 8.5kw shower and i am putting in a 8.7kw shower.
I have a 32A MCB wired to the 8.5kw shower. Will this be enough for the 8.7kw shower or will i need a 40A MCB?

More important is this question,

Will the cable be safe with a 40 amp MCB ?

What size cable is between the consumer unit and the shower and how is it installed ? ( in free air clipped to wall or joist or buried under insulation etc etc ).

 

[rymatom]

How do i tell what size cable it is? do i measure it? the cable goes from the consumer unit, which is downstairs, under the upstairs floor boards then up to the loft. from the loft the cable to the shower is buried into the wall so that you can't see it.