2 circuits on 1 mcb

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Sounds like a physical impossibility. If it's on 1 MCB then it's one circuit.

More info required.

 
is this ok? or bad practice?thanks

paul
If you mean, for instance, 2 radial socket circuits on one MCB; yes its fine, as long as the breaker is selected for the protection of either cable, and all other necessary values are met.

Consider a callout to a property with a socket fault. The board is fully populated with breakers; and you find a damaged cable in the "upstairs ring main".

You cannot access the damage, as its in a wall. What to do????? :eek:

Change the breaker from a 32 to a 20, or even a 16; and remove the offending piece of cable.

You now have 2 perfectly good radial circuits, feeding the upstairs, instead of the ring.

Nothing wrong with that.........

HTH

KME

 
in other cases doubling up circuits i thought was a no?

u would not put a cooker and shower on one mcb, but thats obviouse,

what did u want to double up

 
doubling up does not make 2 circuits. they have a common breaker, so its only 1 circuit. cooker & shower on same breaker is possible, and will be safe. but a little inconvenient when it constantly trips!

 
There is also the option of a spur, which can be taken direct from the cu ie the mcb.

However it would always be classed as 1 circuit and not two.

 
It's the same as the problem I had last week is it not. Shared neutral on the lighting cct's so had to put both on same RCD, this then leads to unsafe isolation when "Lights Up" MCB is off but neutral issue leaves "Lights Down" cct live. To cure, both cct's are placed into same MCB. Safe isolation is the most important thing.

 
When I changed a CU recently I found that the old CU had two rings into one 30A 3036.

 
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