Mounting electrical sockets to shed wall

[MartynBez]

Hi everyone,

I have just had a new shed put up with an internal wall that I want to put a twin socket on to. The issue is the wood is not that thick and not wanting to have the screws come out the other side.

I'm struggling to come up with away to mount the box?

 

[nickjb]

Gripfill a bit of plywood or scrap timber up, or screw the timber up with screws from outside into the timber if you don't trust gripfill. Then screw the socket to that as normal

 

[MartynBez]

Arh didn't think of coming from the other way

 

[JohnD]

screws from outside into the timber

that's a very good idea on a thin shed wall. You don't want the socket coming loose if the flex is accidentally yanked.

BTW if you happen to have a scrap bit of laminated chipboard (as used in kitchens) it's very useful for mounting electrical components on. Non-conductive, doesn't hold damp, very easy to clean, and the surface resists flame or heat.

If your shed is liable to clumsiness, you can get metalclad sockets with matching backbox, which will withstand, say, a garden rake falling onto them quite well.

Your shed supply must be protect with an RCD.

 

[winston1]

Your shed supply must be protect with an RCD.

But if there is already one in the house that feeds the shed supply you don't need another.

 

[MartynBez]

But if there is already one in the house that feeds the shed supply you don't need another.

Any harm in having two?

 

[JohnW2]

Any harm in having two?

Only really the small possible inconvenience of have to go to the house to reset the RCD there if it trips as a result of some fault in the shed (it's basically pot luck as to whether one, the other, or both RCDs will trip as a result of a fault in the shed).

The ideal is for the shed to have its own RCD and for it not to be fed from a circuit in the house which is protected by an RCD which also protects several other house sockets (since a fault in the shed will then kill several house circuits).

Kind Regards, John

 

[winston1]

Any harm in having two?

If (when) there is a fault you will have to reset both. Tedious if the fault is ongoing and will offer no extra protection.

 

[MartynBez]

So if the house end was on an RCD with nothing else wired to it, it would be ok?

I ask as the armour cable from the house to the shed has 2 outside sockets on it.

 

[JohnD]

if there is any possibility that the cable to the shed might be damaged (e.g. with a spade or pruner) then an RCD at the house end will protect it.

This is not so convenient if you are working in the shed and cause a fault, since you will have to walk further to reset it, but it's safer.

edit
An RCD in the house will also protect the outside sockets, which is very important

Its possible to get discrimination using a Time delay, but this is expensive and outside the scope of DIY.

 

[MartynBez]

Ok got it how it should be then. Thanks for the advice

 

[JohnW2]

Its possible to get discrimination using a Time delay, but this is expensive and outside the scope of DIY.

Not only more expensive, but a time-delayed RCD is not really suitable for 'personal protection'.

Kind Regards, John

 

[EFLImpudence]

if there is any possibility that the cable to the shed might be damaged (e.g. with a spade or pruner) then an RCD at the house end will protect it.

Isn't the point of using armoured cable (from house to shed) that it removes the requirement to have an RCD in the house?

 

[John D v2.0]

Isn't the point of using armoured cable (from house to shed) that it removes the requirement to have an RCD in the house?

technically it's not required, but it would still provide some additional protection which I guess was his point.. Also, if it's not buried in walls even T&E wouldn't need RCD protection for that reason either.

 

[EFLImpudence]

technically it's not required, but it would still provide some additional protection which I guess was his point.

SWA does not need that protection. That's the point of using it.

The issues are the house supply being cut by a fault in the shed and the inability to have things in the shed on separate RCDs - lights and tools, for example.

Also, if it's not buried in walls even T&E wouldn't need RCD protection for that reason either.

True.