VD for Sub Main

Spearmint · Jul 14, 2014

I've been thinking about running a supply to my garage for a while, some sockets and lighting etc. the usual. Thinking of burying some SWA as I have some XLPE 2.5mm² three core knocking about into a CU from the house CU. It'll be around a 30-40 metre run but after apply a bit of diversity sticking it on a 20A MCB the voltage drop is far too high considering they'll be lighting on the new CU and that's before adding the voltage drop from the lighting circuit itself.

Any ideas? Or have I missed something? I could get a bigger cable but be a shame to not use it.

telectrix · Jul 14, 2014

you are using the In of your OCPD as a value for current. be honest, how much are you likely to pull? go for a Ib of 10A and you VD will be OK.

Spearmint · Jul 14, 2014

telectrix said:
you are using the In of your OCPD as a value for current. be honest, how much are you likely to pull? go for a Ib of 10A and you VD will be OK.

You're right! It will be pulling pittance for sure, forgot to use Ib instead of In. Thanks a bunch tel!