Mains feed clarification

[hughesy1982]

Hi guys just need some clarification, im wiring a barn conversion which has a mains feed, meter and a small consumer unit installed in one of the out buildings alongside the barn, I need to bring a feed into the barn for the consumer unit which is around a 50m run.

Ive calculated that the cable requires a 25mm swa which will be run into the barn through a duct which has been installed ready.

The bit which i need help with is how to connect from the meter to the consumer unit in the barn. Obviously i cant connect straight into the consumer unit due to the cable size being too big for the incoming terminals.

Do i use 2 large junction boxes either end of the cable to feed both consumer units in the barn and out building?

Thanks

 

[SirKit Breaker]

Hi guys just need some clarification, im wiring a barn conversion which has a mains feed, meter and a small consumer unit installed in one of the out buildings alongside the barn, I need to bring a feed into the barn for the consumer unit which is around a 50m run.

Ive calculated that the cable requires a 25mm swa which will be run into the barn through a duct which has been installed ready.

The bit which i need help with is how to connect from the meter to the consumer unit in the barn. Obviously i cant connect straight into the consumer unit due to the cable size being too big for the incoming terminals.

Do i use 2 large junction boxes either end of the cable to feed both consumer units in the barn and out building?

Thanks

You will need to install a switch fuse within 3 metres of the supply to protect the suppliers kit. then run your SWA from that to your consumer unit. Use a metal clad switchfuse, and you can gland off the SWA. Both switchfuse and consumer unit will accept 25mm cables. I would also use a metal CU so you can gland off the SWA at that end as well. You dont say what type of supply you have, is it TT or TN, if its TT you will need to stick another rod in at the barn CU, if it is TN then stick a rod in anyway just to be safe 50m is a long way to export the earth in my opinion. The switchfuse will need to be rated at less than the supply fuse, they are usually 80a, but 60a if supply is 80a.

Cheers.........Howard