Outside socket

tonywild1985 · Post by **tonywild1985** » Mon Oct 11, 2021 6:16 pm

Hi,

Can you install an outdoor socket as part of a kitchen ring main or will it need to be on its own line?

Thank you

Someone-Else · Post by **Someone-Else** » Mon Oct 11, 2021 6:28 pm

Provided the circuit has RCD protection, yes, you can. If not you could install an external RCD protected socket.
Also it should be spurred from the ring (not a radial) or you could even make it part of the ring.

tonywild1985 · Post by **tonywild1985** » Mon Oct 11, 2021 6:39 pm

Hi Someone-Else,

Thank you for the reply. I have a new ring main going into the kitchen so I would like to add this as part of the ring which you have confirmed is ok. The fuse box is new and RCD protected. I have just purchased a BG RCD outdoor socket. Does it matter that the socket is also RCD protected or shall I send it back and get a normal one?

Thanks

Someone-Else · Post by **Someone-Else** » Mon Oct 11, 2021 7:16 pm

No, you can still use it.

tonywild1985 · Post by **tonywild1985** » Mon Oct 11, 2021 7:30 pm

Great. Thank you

Neelix · Post by **Neelix** » Mon Oct 11, 2021 7:53 pm

Someone-Else wrote: ↑Mon Oct 11, 2021 7:16 pm No, you can still use it.

BUT there is no guarantee which RCD will trip first so I would suggest you change it for a non RCD version

Someone-Else · Post by **Someone-Else** » Mon Oct 11, 2021 9:10 pm

Neelix wrote: ↑Mon Oct 11, 2021 7:53 pm BUT there is no guarantee which RCD will trip first

This is true, but IF it does, he will not have to go inside to reset it.

ericmark · Post by **ericmark** » Tue Oct 12, 2021 9:11 am

RCD's are normally selected so each one is a 1/3rd of the rating to last, so 300 mA feeds a 100 mA which feeds a 30 mA which feeds a 10 mA, however when some one knocked a nail through the cable to hang his coat on, in spite for first two having a time delay as well, they all tripped.

With caravans and boats we have a 30 mA on shore or caravan site plus 30 mA inside caravan or boat, so we do feed one 30 mA from another, but in the main it is considered pointless, but does no harm. 30 mA RCD's are not all the same, we have active and passive and type AC, A, F and B. Having an active RCD on an outside socket means if power fails it stays tripped until you reset it, so if some thing in the garden causes it to trip you can reset house RCD as socket one trips as soon as no power, so often we do use active RCD's for garden supplies.

With AC there is some capacitive and induction linking so there is always a small amount of current to earth, we should measure this when fitting RCD's to decide how much can be supplied from each RCD, personally I never bothered, I just used all RCBO's (MCB and RCD combined) so every circuit has its own RCD, so loss of living room ring final will not mean loss of kitchen ring final.

We call the ring in a house ring final, and the ring supplying a house a ring main, with the ring main in the street a section can be isolated to work on it, all cables can take full current, this is not the case with a ring final, one cable can't take all the current, we all know you mean ring final when you say ring main, just explaining why called ring final.

Because there are always two cables supplying a ring final it is hard to isolate a section, so we tend to use a switched fused spur to feed an outside socket so if it gets water in we can switch it off in the house and continue to use the ring final, rather important in a kitchen with fridges and freezers.

Since you say "new ring main" clearly this will need a compliance or completion certificate and either the electrician will be a scheme member or the LABC will be inspecting and it will have to be RCD protected, personally I have a separate RCBO for outside socket so if it trips don't loose kitchen, I would suggest you do the same.

Outside sockets are OK for class II appliances and most lawn mowers etc are class II, but there can be a problem with class I appliances if your on a TN-C-S supply, so a TN-C-S supply should not be used without special equipment to charge an EV please be aware of that.

tonywild1985 · Post by **tonywild1985** » Tue Oct 12, 2021 3:11 pm

Thank you for the feedback. I do have an electrician coming to do the connecting etc. I wanted to ask before asking him as I was curious!

I don't want to add another fuse spare to the new kitchen. Could a fuse spare for the socket be located in a kitchen cupboard or outside next to it. In a IP66 box?

Thanks

Someone-Else · Post by **Someone-Else** » Tue Oct 12, 2021 3:45 pm

tonywild1985 wrote: ↑Tue Oct 12, 2021 3:11 pm Could a fuse spare for the socket be located in a kitchen cupboard or outside next to it. In a IP66 box?

No point, the mcb will trip before a fuse even thinks about it.

ericmark · Post by **ericmark** » Thu Oct 14, 2021 7:56 pm

You can get outside sockets with either fuses or MCB's or RCD's or RCBO's fitted.

as said often pointless as one in house trips first, I have queried a few times why they are marketed, often called EV charging points, but the instructions which come with them say must have a type B RCD fitted on the supply so does seem rather pointless.