making spare ways

[paul b b]

hello chaps,

is it ok to 'jump' a circuit in with another circuit (somke in with lights) to create a spare way?

also, cu is 16th so all lights on 1 side and 2 showers and 3 rings on the other.

customer wants a feed into a barn so i would like to use the spare on that side but is it ok to have another 50A mcb with all that is on there?

current set up is 6A 6A 6A 6A 6A 16A (un pro) 50A 32A 32A 32A sp 50A

thanks

paul

 

[batty]

I personally would put seperate consumer unit in for barn that way its easy to isolate if necessary and if you are putting a 50 amp circuit in thats quite a bit of load on existing consumer unit.

 

[vandalay]

Could you not run as little garage unit into barn which would also give some local isolation in it.

 

[paul b b]

i was going to run 16mm to a samll cu in the barn (its not going to be lived in just a few sockets and a light)

 

[paul b b]

Could you not run as little garage unit into barn which would also give some local isolation in it.

thats exactly what i was going to do but still need a mcb to run it off

 

[tom1]

50 amp is a bit much for that what about 2.5mm 0n a 20 amp

 

[paul b b]

will have to talk to customer to see exactly what they want.

thanks chaps

 

[Lurch]

is it ok to 'jump' a circuit in with another circuit (somke in with lights) to create a spare way?

Yes, as long as the circuit you create isn't overloaded or leaves something un or incorrectly protected.

As for the '50A is too much' comments, depends on what's on the other end. You could put an 80A MCB in, but if the far end is feeding a board with a 20A and a 6A MCB in it then it doesn;t really matter what the MCB on the submain is. Also, Nothing wring with adding another 50A circuit, as long as the board isn;t being overloaded. I don't think you'll have a problem if you're just running another ring and lighting circuit round the barn. You should do some calcs and use some judgement though and check the existing loadings on the board.

 

[Evans Electric]

Theres always the old dodge of taking ,say 2 light cts out ,feed a two way C/U from one way with a 16 A fuse/MCB and use the remaining way for your new ct. A 50A X 16mm sounds OTT to me , I'd go with Tom1 ... 2.5 from a 20A way .

Deke

 

[ianmacd]

Doesn't that all depend on diversity. Couldn't then fit a ring with a 32A and 6A lighting on the end of a 20A mcb. Also should be not on standard RCD on house side for same reason (time delay is ok).

Ian.

 

[Lurch]

Doesn't that all depend on diversity.

That's what I was trying to say.

Also should be not on standard RCD on house side for same reason (time delay is ok).

Lost me a bit here?

 

[Apache]

Lost me a bit here?

Lurch seems to have a problem understanding Ian.

I know he's talking about discrimination

 

[ianmacd]

RCD descrimination. You need to either have no RCD or a time delayed RCD at the house end if there is also one in the garage/shed/out-building/whatever to allow for diversity. Since it is classed as a distribution circuit it does not need RCD protection (unless its required for other reasons like depth of cable buried in wall but using SWA can negate that need anyway).

Ian.

 

[Lurch]

That makes sense. Thought you were saying something else, which didn;t!

 

[spinlondon]

I don't see the need for such a large cable/MCB. Is it because of Volt Drop, or perhaps bonding?

I'd say at first glance a 32A MCB and 4mm

 

[kme]

I`d agree - unless, as spinny says, distance becomes an issue..........