Electrical help

Mark M · 9 Jul 2020 at 11:10

I have an outside socket in the garden and the cable comes into the garage (approx 30cm off the ground, assume so it was above the DPC) and into a standard plastic back box with a plastic blanking face plate. Inside it connects to some flex with wago connectors and plugs into a socket via some trunking.

Ive just dropped a spade on it and broke the backbox!

Firstly, is the existing wiring ok or is it a total bodge?

Secondly, if its "ok", what should I replace the back box with? I was thinking something like this instead with it being in the garage?

Many thanks.

eviled · 9 Jul 2020 at 12:00

wagos in a accessible box is fine.

From memory of just wiring my own outdoor spur it should be fused. I'd use something like this https://www.screwfix.com/p/mk-metal...ts/22894#product_additional_details_container

Happy to be corrected by someone if I'm wrong however

Mark M · 9 Jul 2020 at 12:11

eviled said:
wagos in a accessible box is fine.

From memory of just wiring my own outdoor spur it should be fused. I'd use something like this https://www.screwfix.com/p/mk-metal...ts/22894#product_additional_details_container

Happy to be corrected by someone if I'm wrong however

Thanks, I randomly have one of those exact spurs in my spare bits box but when I've looked at it there is no "entry" holes on the back and only the sides but I'd like to protect the cable entry too if possible. Can I drill a hole in the back and put some electricians tape over any rough edges?

200sols · 9 Jul 2020 at 12:16

Is it an armoured cable?

eviled · 9 Jul 2020 at 12:27

Mark M said:
Thanks, I randomly have one of those exact spurs in my spare bits box but when I've looked at it there is no "entry" holes on the back and only the sides but I'd like to protect the cable entry too if possible. Can I drill a hole in the back and put some electricians tape over any rough edges?

if its that exact one then it has a hole that's tack welded in and can be knocked out with a punch + hammer

if no then a 20mm hole a 20mm grommet is the proper way to do it

Mark M · 9 Jul 2020 at 12:47

200sols said:
Is it an armoured cable?

No, its just rubberised 3-core cable.

eviled said:
if its that exact one then it has a hole that's tack welded in and can be knocked out with a punch + hammer

if no then a 20mm hole a 20mm grommet is the proper way to do it

Hmmm, must not be the exact same one then as it only has a hole the size of screw in the back at the centre.

200sols · 9 Jul 2020 at 15:14

Mark M said:
No, its just rubberised 3-core .

Crack on then, the cable should go through a grommet but they are often not fitted by lazy sparkies.

Drill hole and use grommet is fine, electrical tape is a bit of a bodge.

lewism · 9 Jul 2020 at 21:10

You'd be as well taking a photo.

rubberduck · 10 Jul 2020 at 12:46

Should be ok, there are some weird regulations regarding unsecured wagos in back boxes and how this relates to their current carrying capacity but I wouldnt worry about it. Main thing I would check is the cross sectional area of the conductors in your cables... Ideally it's 2.5mm2 but 1.5mm2 will probably be fine. If something really small like 0.75mm2 i.e someone has used lighting cable you probably want to change it out. Does you garage have a consumer unit or is your circuit on your main consumer unit in your house? You want any outdoor socket to have RCD protection. If this isn't present on the consumer unit you can buy a socket with its own RCD but they are a little more expensive.

Mark M · 10 Jul 2020 at 13:50

rubberduck said:
Should be ok, there are some weird regulations regarding unsecured wagos in back boxes and how this relates to their current carrying capacity but I would worry about it. Main thing I would check is the cross sectional area of the conductors in your cables... Ideally it's 2.5mm2 but 1.5mm2 will probably be fine. If something really small like 0.75mm2 i.e someone has used lighting cable you probably want to change it out. Does you garage have a consumer unit or is your circuit on your main consumer unit in your house? You want any outdoor socket to have RCD protection. If this isn't present on the consumer unit you can buy a socket with its own RCD but they are a little more expensive.

The cable is 2.5mm thankfully or I would have wanted it redone. The consumer unit is in the garage but this outdoor socket actually plugs into a socket that the garage door is also plugged into and not on its own circuit, the consumer unit is labelled "G-Door + Outdoor Sock". It has no RCD protection currently.

rubberduck · 11 Jul 2020 at 10:11

Mark M said:
The cable is 2.5mm thankfully or I would have wanted it redone. The consumer unit is in the garage but this outdoor socket actually plugs into a socket that the garage door is also plugged into and not on its own circuit, the consumer unit is labelled "G-Door + Outdoor Sock". It has no RCD protection currently.

Can you isolate the garage consumer unit from one of the MCBs in your main consumer unit in your house? If so it could be RCD protected there which would also be fine. If not just buy an RCD outdoor socket from Toolstation or Screwfix for £20 or so.

Mark M · 11 Jul 2020 at 15:11

rubberduck said:
Can you isolate the garage consumer unit from one of the MCBs in your main consumer unit in your house? If so it could be RCD protected there which would also be fine. If not just buy an RCD outdoor socket from Toolstation or Screwfix for £20 or so.

Sorry, not sure I totally follow. The main consumer unit for the house (the thing with all the switches on) is actually in the garage (garage is connected to the house) and one of the switches is used for the garage door and this outside socket so do I still need it’s own rcd protection? I have some spare slots in the consumer unit so would it be better to get the outdoor socket on its own one or would the rcd still be needed?

rubberduck · 13 Jul 2020 at 16:57

Mark M said:
Sorry, not sure I totally follow. The main consumer unit for the house (the thing with all the switches on) is actually in the garage (garage is connected to the house) and one of the switches is used for the garage door and this outside socket so do I still need it’s own rcd protection? I have some spare slots in the consumer unit so would it be better to get the outdoor socket on its own one or would the rcd still be needed?

Sorry, am with you now. It could be that your garage door/socket MCB is already RCD protected. Does your consumer unit have any RCDs? If not sure just take a picture of it.