(UK) Sanity Check Kitchen Oven wiring spur

[dande650]

Hello, I'm hoping someone who knows more than me can sanity check this wiring diagram for my Electric Oven, Extractor Fan and Gas Hob.



Background: I bought a new oven, I thought the old one was plugged in with normal plug but it was actually hard wired and the extractor/hob were plugged in. The sockets and fuse box were already there, but I didn't take a picture of the wiring before swapping the ovens, my new oven has a proper plug attached to the flex - the extractor and hob are the diy add on plugs.

I want to re-wire the set up to plug in the oven and hob, then hard wire the fan so I can use all 3, but dont know which side of the fuse box the old oven was wired into, and then don't know which side of the fuse to wire the fan into.

Concerned about either pushing the full ring power into the fan (if thats a thing?) if it's before the fuse, but then overloading the fuse if its after and everything is running at once.

Details : Electric Oven 2850W, 220-240 V so max current of 12.9A , don't know wattage of the hob nor fan and cant fins a sticker/model number.


Hope that makes sense, thanks for any help!

 

[Lucien Nunes]

Gas hob ignition uses effectively zero (a few watts while you hold the button) and and the extractor very little, less than 100 watts. So the only significant load is the oven. The extractor fan manufacturer might stipulate a maximum fuse size that may be used to protect it.

But your setup is a conundrum because the spur cable from the ring is only supposed to feed one point, whether that be a double-socket or a fused connection unit. On that basis the spur from the ring must go first through the FCU with a 13A fuse, then to the socket and fan. I would put a second FCU as an isolator for the fan, in parallel with the socket, and the fan maker might well stipulate a smaller fuse in which case you could put e.g. a 3A fuse in the second FCU. (It would not be acceptable to connect the fan before the first FCU as the ring's 32A MCB will not offer the protection it requires.)

Electrically it is actually slightly better to power the socket and the fan FCU both from the unfused spur and dispense with the first 13A-fused FCU, as that removes a needless point of heat dissipation at the FCU fuse as would runs almost at full load when feeding the oven. The oven and hob are then still protected by their plug fuses and the fan by its own FCU with 3A fuse. However, many would argue that it would be non compliant as the unfused part of the spur is feeding two points - the FCU and the double-socket - when only one is explicitly permitted.

I am sure there will be debate on this one!

 

[hasel5]

Is this setup actually on the Ring?
Or on a separate supply in 6mm?