doubled cable on a radial

[Ducksy]

Hey guys I see this now and again on my rounds....8.5kw method C on 2 x 2.5mm cable......does it state anywhere in the regs that it a radial must be a single cable Or is it acceptable ? the very least i think its lazy not using 6mm but as always I'm well off from the more experienced guys think

Thanks

 

[RyanCheetham]

You can run cables in parralell but they must be identical with the same resistance values

 

[Ducksy]

Sweet would you say that the cables CSA totals 5mm.....as it could be the case the CCC is not sufficient.

 

[telectrix]

and the cables must take the same route. if protected with a 40A MCB, the cables should not be overloaded, method C, but , not good practice, IMO.

 

[RyanCheetham]

Yes the csa would be 5mm

 

[Ducksy]

Great that's what I was thinking thanks tele and Ryan

 

[Guitarist]

I've seen that method of supply to old garage fuseboards on a 30A fuse, but never to a shower.

 

[sparkymalarky]

What happens when the shower is replaced with a 500kW unit? Kablammo. height of laziness! who be arsed pulling in and clipping 2x2.5mm² cables when 1 x 6mm² would have been handier, easier, safer etc.

 

[Fin170]

What happens when the shower is replaced with a 500kW unit? Kablammo. height of laziness! who be arsed pulling in and clipping 2x2.5mm² cables when 1 x 6mm² would have been handier, easier, safer etc.

Going to need, probably, at least 2x6mm I think......or it's own power station :lol:

 

[sparkymalarky]

A good 10mm² will sort it out. :21:

But getting back to the point, not ideal, but if they are on a 40A protective device, no rules being broken technically.

 

[Ducksy]

I've seen it quite a few times......realistically this is a ring final circuit.....just with one point.

 

[kingeri]

Poor practice but not against the regs as far as I know. As said though, why do it?

 

[Guitarist]

Poor practice but not against the regs as far as I know. As said though, why do it?

They probably had a reel of 2.5mm from the RFC and didn't want to pay for a length of 6 or 10mm

 

[markythesparky]

How would you work out the current carrying capacity of this set up? If its a ring then the maximum overcurrent device allowed is 32a, but this is 5mm??!?!?! where is this cable in BS7671.

Also what happens when one of the phase or neutrals comes out?

i wouldnt be thinking this is an acceptable way of doing things but hey this is why this forum is here!

 

[Ducksy]

How would you work out the current carrying capacity of this set up? If its a ring then the maximum overcurrent device allowed is 32a, but this is 5mm??!?!?! where is this cable in BS7671.

Well i figured method c 4mm = 37a

6mm = 47a

so i'd say 42a for 5mm