Sealing an outdoor socket

[vexorg]

I'm looking to fit an outdoor socket in the back garden.

Something like this as MK usually are good quality: https://www.mkelectric.com/en-gb/Products/CP/SentrySocket/Masterseal/Pages/56231.aspx

I am an electrical engineer, and had no issue with wiring sockets, lights etc for many years in the house. So the mounting and wiring is not an issue as it'll be a spur off a socket on the other side of the wall.

What I cant seem to see anywhere is guidance for sealing the back of the box to a brick wall. Is it enough to put a bead of silicon sealant on the back face of the box, to keep water or moisture getting in through the hole where the wires feed through on the back of the box?

 

[ktuludays]

Yes, bead of clear silicone should be suffice

 

[Harry Bloomfield]

Make sure that any water which does get in, has a means of escape. Rule is prevent water getting, but make sure there is a way out for it.

 

[EFLImpudence]

I am an electrical engineer,

 

[phatboy]

I use Weatherproof Compound

https://www.tlc-direct.co.uk/Products/BIR391.html

 

[vexorg]

vexorg said: ↑
"I am an electrical engineer"

There's always one.... I know the regs, and have done a lot of industrial wiring over the years too, but couldn't see anything specific about sealing outdoor sockets to meet any kind of standard. No point have a socket that meets all the BS standard if there's a big hole in the back.

 

[vexorg]

Make sure that any water which does get in, has a means of escape. Rule is prevent water getting, but make sure there is a way out for it.

Yes, there are options for drain holes built into the MK socket.

Thanks all (well nearly all)

 

[winston1]

Do you actually need a RCD socket? Don't you have an RCD in your CU?

 

[vexorg]

I was going to check that, it's from my garage beside the house and it has it's own CU since the garage was the office for the show houses. I'm not sure if the garage if fed from the CU in the house, or tee'd off before the house CU. The house CU has an RCD, need to check the garage.

Belt and braces approach might be best as one of these lazy spa things will be plugged in.

 

[Aunsh]

IIRC the Masterseal boxes are intended to be wired through one of the conduit KOs and do not have any mehanism for wiring through the back. There is also a requirement to drill out the bleed hole to 5mm in some instances, depending on the conduit arrangement. Having said that, it seems an easy option to (carefully) drill through the back and seal the back face to the wall, ensuring the bleed hole is left open.

 

[vexorg]

It was just an assumption that there'd be an option to go out the back of the box straigfht through the wall. If it's not an option then I can use a bit of conduit, then whole question is a bit pointless....

Probably the way to go and not affect the IP rating.

 

[Taylortwocities]

I was going to check that, it's from my garage beside the house and it has it's own CU since the garage was the office for the show houses. I'm not sure if the garage if fed from the CU in the house, or tee'd off before the house CU. The house CU has an RCD, need to check the garage.

Belt and braces approach might be best as one of these lazy spa things will be plugged in.

As you are an “electrical engineer” surely your training will have told you that you need to know the answer to these very very elementary questions before you start any project.

“Not sure” isn’t the way things are done.

 

[HERTS P&D]

Probably the way to go ................................

Is to call someone out who knows what to do.

Andy

 

[SUNRAY]

Belt and braces approach might be best as one of these lazy spa things will be plugged in.

Have you checked the power rating and MI's for the Lazy Spa? some versions need something other than a 13A socket.

 

[ericmark]

I must admit as an electrical engineer (level 5) I am still learning and I have made errors. One is in advising people if their CU is RCD protected there is no need for a RCD socket, on the surface this seems correct, but as you look at the types of RCD then not so cut and dried.

The K6211 range do both 10 mA and 30 mA versions, I have a 10 mA version, it was originally fed from a 100 mA RCD and the big problem was if some one presses the test button it took out both the 10 mA and the 100 mA RCD, and as with may RCD's it does not actually say that type it is, I would guess type A as it says "They are a.c. and pulsating d.c. sensitive for residual current.".

If the CU has type A then no real point in a RCD socket, but if type AC then there may be a good reason, however I am still unsure about the types of RCD.