Dodgy Garage

[davedasave]

Hi, I know you all like dodgy photos of bad installations so thought i'd share this photo I took of my mates garage

He asked me to go round and look at his car last night, and as I was about to plug in a battery charger I saw this but thought better of it, his garage is at the bottom of his garden fed by swa cable (don't know what size) which is connected to his cu on its own circuit by a 32A mcb on the rcd side of his board.

I've told him he needs to get a garage cu with 40A 32mA rcd with a 6A and 16A mcb and run everything off that but was also concerned about the earth as the whole roof is held up by those metal supports, any suggestions?

 

[luminaire]

I'd hate to think what the rest of his electrics are like

 

[ban-all-sheds]

Hi, I know you all like dodgy photos of bad installations so thought i'd share this photo I took of my mates garage

Like the snail...

his garage is at the bottom of his garden fed by swa cable (don't know what size) which is connected to his cu on its own circuit by a 32A mcb on the rcd side of his board.

Looks like the SWA goes straight into that socket. Hope it's 3-core...

How are his lights powered?

I've told him he needs to get a garage cu with 40A 32mA rcd with a 6A and 16A mcb and run everything off that

Shouldn't have an RCD if it's got one at the house (but moving it off that is a good idea).

but was also concerned about the earth as the whole roof is held up by those metal supports, any suggestions?

Those metal trusses usually just sit on the walls - they are not connected to earth.

That roof, BTW, might have asbestos in it.

 

[davedasave]

thanks for the reply, the swa does indeed go straight into the socket, but on the oppsoite side to the photo, the cable coming out goes to a security light on the outside wall, he doesn't have lights down there, but does use a bulb holder connected to a plug via 2 core so just plugs it in when needed

i think he wants me to fit it so don't really want to be messing about in the cu taking the circuit off the rcd side, other than doing that is there another way to make it safer? can it not have 2 rcds? the one in the garage being rated lower so it trips that before it trips everything in the house?

good news about the earth, and the cable is 3 core, brown, blue and green/yellow

 

[ban-all-sheds]

You could install a garage CU if you want, but that makes the work notifiable. You'll not be able to get an RCD that discriminates with the one in the house though, so you'd only be doing it to get some MCBs there, and you have to wonder what the point of that would be.

Plan B would be to replace that socket & flush box with a proper metal clad one, gland the SWA properly to it with banjo/piranha and flylead etc.

(I take it the armour is earthed at the supply end?)

Ditch the cable ties and bolt the box to the truss (you should probably take an earth lead to that as well), and add a couple of metalclad FCUs, an unswitched one for the outside light and a switched one for the internal one.

 

[davedasave]

thanks, that sounds a lot easier

i have no idea if the swa armour is earthed but looking at the way its connected in the garage i wouldn't have thought so!

when you say take an earth lead to the truss, how would i do that?

also you say metal clad, i take it they are the grey/blue type boxes that you see in factories etc

thanks for your help

 

[ban-all-sheds]

i have no idea if the swa armour is earthed but looking at the way its connected in the garage i wouldn't have thought so!

It needs to be.

when you say take an earth lead to the truss, how would i do that?

Drill a hole in it, clean off the rust, crimp an eyelet onto the end of a G/Y single and bolt it to the truss. As you've got an earthed socket box bolted to the truss it's become an exposed conductive part. OK - it's almost certainly going to be adequately earthed via the bolted on socket box, but an extra precaution does no harm.

also you say metal clad, i take it they are the grey/blue type boxes that you see in factories etc

The knockout holes are 20mm, so the right size for a SWA gland, and you can connect the two FCUs and the socket box together with 20mm conduit bushes & locknuts etc. For the cables out to the lights you could just use grommets, so the spiders don't lose their home, or closed grommets that you cut a slit in, or compression glands.

 

[davedasave]

just got back from my mates house and the swa armour is indeed not earthed where it takes it supply from, the trouble is it is in a dry lining box (the sort with the sliding screw holes)

can i earth the armour using this or will i have to change the box to a metal one, could be tricky unless i can move it to a joist

 

[ban-all-sheds]

I wouldn't fancy your chances of glanding SWA to a dry-lining box...

 

[Dartlec]

hmm, but if he fitted a gland to the SWA purely to allow earthing of the armour and left the join in a dry lining box, would that be A Bad Thing™? After all, the box itself doesn't need to be earthed, which is the usual reason for fitting the gland to the box...

There may be mechanical support implications of course, but then there are already, and this way would at least provide an earth.

Thats assuming there is space for the gland inside the box of course...

 

[securespark]

Make the SWA off into a 2G box, then continue in T & E...

 

[ban-all-sheds]

hmm, but if he fitted a gland to the SWA purely to allow earthing of the armour and left the join in a dry lining box, would that be A Bad Thing™? After all, the box itself doesn't need to be earthed, which is the usual reason for fitting the gland to the box...

Ah - the spirit of Acca Dacca and his waving-in-the-air SWA glands lives on...

I see your point, and sort of see the sense, but it doesn't seem right...