DIY Doctor UK DIY Forums

hi
I have an existing cooker circuit on 4mm cable, according to my calcs it can cope with 7.5kw load, i wish to fit 2 single fan ovens (3.3kw total load each) am i correct in this?

The circuit runs to a cooker socket ( plus single plug socket) then across to the oven housing (still in 4mm) there is plenty of cable length to connect in series, or is it preferable to fit an outlet plate behind the housing and wire in either series or paralel from the plate. In either the same 4mm cable or a heat resistant flex.
The oven spec says cable of H05VV-F spec or greater, though doesnt give a cable size, bloody helpful. In theory 1.5mm handles 3.3KW wired in paralel and could be done in heat resist flex as this would be easier when refitting the ovens into the carcus than 4mm cable. Or is this not permissable.
The cable from the connection plate in the oven looks to be approx 1 or 1.5mm so 4.0mm cable seems OTT.
Also would i be right that a fuse downsize to approx 25amp is required.

P.S
The house is due a periodic inspection when all the works are complete

i'd appreciate any advice

Cable sizes to the cooker switch would depend on how it is routed see http://www.ericpalmer.fsnet.co.uk/Table4D5.html
You are also required to follow manufactures instructions they may stipulate the supply fuse/mcb size.
Also you must include a fuse/mcb at any point where you reduce cable size within 3 meters of the reduction.
If they are being fitted in a kitchen then you will also need to notify the local authority building control.
You need to inform the LABC before you start and the PIR has nothing to do with the completion certificate to get completion cert you need to complete either a minor works cert or installation cert and the reading required are not really within a DIY persons ability.
Because registered electricians can issue their own completion certs it is often cheaper to get it done than DIY.
Eric