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Combining 2 radials into one

Postby Pglen » Tue Mar 22, 2011 4:12 pm

As part of a kitchen make-over I'd like to replace the 2 circuits I have (one for hob and one for oven) with a single one.

The current set up is that each circuit has a 6mm cable from a two separate MCBs to two CCUs - is there any reasons why I cannot combine these into the one MCB and the one CCU, freeing up an MCB on my board and meaning I only need one CCU in the kitchen? ie connecting two 6mm wires into the same MCB and CCU.

The power ratings for the appliances are approx 3Kw and 6Kw.


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Postby stoneyboy » Tue Mar 22, 2011 9:51 pm

I assume the MCBs are both 32A at the moment. If you used everything on both oven and hob then you would taking something over 37A which could lead to nuisance tripping with just one MCB.
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Postby ericmark » Wed Mar 23, 2011 4:44 pm

The rules are complex and although in theory a 32A (7.36kW) supply may feed both items with diversity the question must be asked why were they separate in first place.

In designing a circuit we look at many things.
* What is the maximum rating we can supply the item with? If a oven needs fusing to 16A then you can't combine it with a oven because of max MCB size. Under 13A you could use a fused connection unit.
* What is the load clearly 7.36kW is not the same as 9kW and you could end up with it tripping.
* What feeds to consumer units will the consumer unit take the extra power.

Even if these are OK and all other parameters are also OK then you have the problem of Part P and paying the LABC fee.

So I would get an electrician to visit and advise he may have a way around the problem you have not thought about.
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