Putting a Commando/CEE socket in the garage

fwor

I'd like to have a 16A Commando socket inside my garage, for two uses - occasional electrical hookup to a caravan/motorhome outside, and occasional use to supply a MIG welder which requires a 16A single phase supply.

I've got a split-load consumer unit with all existing internal circuits on one RCD, and the other RCD reserved for future "external" use, but as yet unused.

The unused RCD has two MCBs - one for future external lights, and the other - rated 32A - for external power outlets (one for a pond pump and the other for garden tools).

Would it be better to replace that MCB with a 16A one and wire the Commando socket and other two external sockets to that, or should it be wired from the 32A MCB to a separate external enclosure with a 16A MCB which serves just the Commando socket (plus space for another MCB for the external 13A sockets when I finally have those installed)?

I should add that I am ~not~ asking for advice on who is allowed to make these changes.

Owain_Moneysaver

the separate MCBs would be preferable, otherwise your total load will be limited to 16A.

you should also use a Commando socket that has interlocking with a switch to prevent the socket being live with no plug in it. This is because commandos aren't shuttered and IEE regs require sockets in domestic premises to be shuttered. Using an interlocking socket means you can claim a deviation from the regs with an equivalent standard of safety.

fwor

Owain_Moneysaver wrote: »

you should also use a Commando socket that has interlocking with a switch to prevent the socket being live with no plug in it.

Thanks - that's extremely useful. I'd looked at the MK ones with interlock, but balked at the £70-odd price. Sub-£20 is much more reasonable!

So I would be running a short link from the 32A MCB to a separate enclosure with a dedicated 16A MCB for the commando socket, a 20A MCB for the external mains radial and a 6A MCB for the external lighting. Seem sensible?

southcoastrgi

Owain, i don't even know why you are giving advice ?

The OP has already said he isn't looking for advice on who is allowed to make these changes, which says to me he is going to do the work himself & as he has to ask for advice then he clearly isn't a reg sparks as they would know the answer & as the work MUST be done by a part p sparks then you shouldn't really be telling him how to DIY

fwor

southcoastrgi wrote: »

The OP has already said he isn't looking for advice on who is allowed to make these changes, which says to me he is going to do the work himself & as he has to ask for advice then he clearly isn't a reg sparks as they would know the answer & as the work MUST be done by a part p sparks then you shouldn't really be telling him how to DIY

I suspected I was going to get this sort of thing.

You don't know that I am going to do the work myself - you can't infer that from what I wrote.

Another explanation could be that I would like to have an idea of how it should be done before speaking to an electrician, so that I can get an idea of whether he/she knows what they are doing. I've found in the past that it always helps to approach such things from a position of knowledge rather than ignorance.

And since you quoted the following as a fact "the work MUST be done by a part p sparks" let me check - is that actually true? Or can any competent person do it provided that they go through the correct notification and inspection procedures before it is connected to the existing installation?

tlh858

fwor wrote: »

Or can any competent person do it provided that they go through the correct notification and inspection procedures before it is connected to the existing installation?

A competent person could notify building control, pay the £200 or more fee, then install the socket themselves, then request that BC inspect the works and provide a completion certificate.

However, if someone needs to ask basic questions about how to install the thing, which MCB to use etc. then clearly they are NOT competent to do it themselves.

A similar situation exists with gas. In theory, it is perfectly legal for someone who is competent to install gas items in their own home.
In reality, DIY gas is not legal, because those who think they can do it themselves are very far from being competent, and even if by some miracle they actually were, how will they prove this when half of the street explodes due to a gas leak?

It is also highly unlikely that anyone would ask specific questions about the work if they were going to have someone else do it.
The few that do are the sort who no tradesperson would ever want as a customer, since they are the ones who believe they know better, will demand things are installed in a certain way (even if that is completely wrong), want to pay virtually nothing and then want an extra discount, and complain bitterly about every part of the work for any and every reason they can think of.
They are usually the ones which complain no one will provide them with a quote for anything, or if they get a quote, it is 10 times more than anyone else paid for similar works.

For information, this is wrong:

fwor wrote: »

So I would be running a short link from the 32A MCB to a separate enclosure with a dedicated 16A MCB for the commando socket, a 20A MCB for the external mains radial and a 6A MCB for the external lighting.

fwor

tlh858 wrote: »

For information, this is wrong:

Thanks, you've been very helpful.

Why does this part of the forum often seem to generate threads like this?

I ask for some simple, factual information. One person is helpful and then the rest pile in with information that I don't need and didn't ask for.

What exactly is wrong with asking how it should be done properly? If I'm considering getting some work done on my house, why would I ~not~ seek that information from several independent sources?

southcoastrgi

because you are trying to DIY something that is not a DIY job, i don't believe from all the information you are after that you are gonna get the proper person in to do the job, if you get a decent sparks you don't need to question everything he says or tell him he's doing it wrong (or you think he is) because if you do he will just tell you where to go

southcoastrgi

fwor wrote: »

Thanks - that's extremely useful. I'd looked at the MK ones with interlock, but balked at the £70-odd price. Sub-£20 is much more reasonable!

So I would be running a short link from the 32A MCB to a separate enclosure with a dedicated 16A MCB for the commando socket, a 20A MCB for the external mains radial and a 6A MCB for the external lighting. Seem sensible?

not doing it yourself ??

fwor

southcoastrgi wrote: »

not doing it yourself ??

You don't seem to have a very flexible mind.

I am asking how it should be done properly, but you just seem to be determined to make unfounded assertions about my competence and about who might be going to do the work.

I don't need your advice on either of those things. In fact, as your advice that "the work MUST be done by a part p sparks" was wrong, I doubt I need your advice about anything.

southcoastrgi

when it comes to safety & stopping people from killing themselves & others then no i don't have a flexible mind, you are correct in saying you can if you are compitant do it, however i didn't realise that you wanted to give your local building control more money than it would cost you to get the job done properly by a reg sparks not very MSE is it, so i still stand by what i say fitting a new circuit & upgrading or moving anything in your fusebox is not a DIY job.