2 circuits on 1 mcb

[paul b b]

is this ok? or bad practice?

thanks

paul

 

[Lurch]

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

More info required.

 

[kme]

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?????

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

 

[paul b b]

thanks kme

 

[tom1]

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

 

[Andy™]

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!

 

[Apache]

But Batty doesn't like it!

 

[Andy™]

But Batty doesn't like it!

then batty will just have to not like it!

 

[paul b b]

just to make this clear, i am refering to lighting. the job i have to do my be better if i use 2 feeds.

thanks for the advice

 

[tom1]

[quote name='Andy

 

[batty]

But Batty doesn't like it!

I am not getting in to arguments tonight have bills to do.

 

[green-hornet]

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.

 

[safedepth]

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.

 

[kme]

If the O/P has 2 seperate "ends" to parts of, say, the downstairs lighting cct, there is no reason for using seperate ccts, as long as segregation is complied with.....

 

[spinlondon]

It appears you have found your Scooby.

 

[mojorebel]

as long as the Ib and In relationship is correct you are fine

 

[musicspark]

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

 

[Andy™]

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

not good practice, but nothing dangerous about it

 

[batty]

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

Your lucky I usually find they are four radials.

 

[BangBang]

So long it follows the same route and of equal loading

John