Quick electric question.
Old oven blew up on tuesday so I disconnected it and getting a new one delivered tomorrow.
I had a Belling Bi70fp double oven and replacing it with a AEG COMPETENCE BP3003021M single oven.
Supposedly the Belling was 32A fuse size, the AEG is 16A Fuse size.
Can I just wire up the new oven with the connected wire from the old oven?

Depends on the zize of the cable but its quite possible. The existing cable might not fit the terminals of the oven if it is designed for smaller cables though. Any pics of cable?

The cable is quite thick, thicker than the stuff i’ve used in the past for lights etc. Probably double thickness.

If the fuse is lower rated in the new oven, then the heavier duty cabling should be fine.
Im not a lectrishun though.

I did this. The cable for the old oven was massively overrated for the new oven. Just changed the trip for it and was good to go. Bit of a ball ache getting it into the new oven terminals but all do-able.

The existing oven cable is probably 6mm twin and earth with a 32 or 40 amp MCB. You’ll need to use at least 6mm cable for a 40a MCB, or at least 4mm for a 32A MCB. If you want to use smaller cable than that you’ll need to change the MCB in the consumer unit – 20A for 1.5 or 2.5mm cable.

I would suggest 2.5mm cable with a 16A MCB. (3.5kW = 15.2 amps at 230v).

IAAE but I’m not on site so it’s guidance only. If in doubt get someone qualified to look at it.

Rich.

I did this. The cable for the old oven was massively overrated for the new oven. Just changed the trip for it and was good to go. Bit of a ball ache getting it into the new oven terminals but all do-able.

What he said. Overrated is fine if it will fit securely for the cable, but get the MCB swapped.

If I just change the MCB will I need a 16A one?

The MCB size is determined by the size of the cable you use. If the cable is 6mm all the way from the MCB to the cooker then you can leave the MCB alone. If you downsize the cable the MCB should always be sized such that its rated current is less than current carrying capacity of the cable. So, if you downsize to 2.5mm cable the MCB should be less than or equal to 27 amps (the rating of 2.5FTE), so a 16A or 20A would be ok. Can’t be less than 16A though as the load is 15 amps.

So, to summarize – a 16A MCB is ok and you can go as small as 2.5mm on the cable size.

I should add that cables run in insulation have a lower maximum current rating than those in a concrete wall so this may influence what is used. Difficult to tell without seeing it “in the flesh”. For this reason I’d probably use as big a cable as can fit. 4mm better than 2.5mm; 6mm better still.

Rich.