UK Is this method of earthing backboxes standard ???

[Azrael]

My housing association are rewiring the high-rise flat, and I've noticed they are earthing the lightswitch backboxes by using a small ring on the earth wire connecting the old backboxes using the faceplate screw to the backbox lug. Is this industry standard or bad practice, and is it safe

 

[PS Electrics]

My housing association are rewiring the high-rise flat, and I've noticed they are earthing the lightswitch backboxes by using a small ring on the earth wire connecting the old backboxes using the faceplate screw to the backbox lug. Is this industry standard or bad practice, and is it safe

A photo might help.

As explained and if I understand what is going on I would suggest this is not acceptable I cannot see how they can be sure the earth wire is making good contact when the accessory is screwed back since it will not be clamped as there is normally a gap.

The lug in the back box would need to be a fixed one as well.

The best way to do this is to drill and tap the back box.

 

[littlespark]

Is it twin and earth cable, or rewiring singles into existing steel conduit embedded in the walls? There may already be a decent earth through the conduit when tested.

I do agree that a hole should be drilled in the box, and tapped to M4 to screw in an earth stud.
If I’m understanding… they’re using the M3.5 box lug top or bottom of a switch which are otherwise unused?
The standard 3.5 machine screws that come with switches aren’t threaded right up, so it doesn’t tighten up as explained above

 

[Azrael]

A photo might help.

As explained and if I understand what is going on I would suggest this is not acceptable I cannot see how they can be sure the earth wire is making good contact when the accessory is screwed back since it will not be clamped as there is normally a gap.

The lug in the back box would need to be a fixed one as well.

The best way to do this is to drill and tap the back box.

t

 

[Azrael]

Is it twin and earth cable, or rewiring singles into existing steel conduit embedded in the walls? There may already be a decent earth through the conduit when tested.

I do agree that a hole should be drilled in the box, and tapped to M4 to screw in an earth stud.
If I’m understanding… they’re using the M3.5 box lug top or bottom of a switch which are otherwise unused?
The standard 3.5 machine screws that come with switches aren’t threaded right up, so it doesn’t tighten up as explained above

A photo might help.

As explained and if I understand what is going on I would suggest this is not acceptable I cannot see how they can be sure the earth wire is making good contact when the accessory is screwed back since it will not be clamped as there is normally a gap.

The lug in the back box would need to be a fixed one as well.

The best way to do this is to drill and tap the back

thank you very much for your reply i have posted a photo and as you can see the earth is just sitting on the face plate screw

 

[littlespark]

No way.

That’s not a secure fixing.

Needs to be brought up with whoever’s running the job.
Has this been rewired? Is it two brown cables there, or black?

Brass bush at the box hole… so maybe it is steel conduit.
Still doesnt make sense to just hang the earthwire off a screw.

 

[Azrael]

No way.

That’s not a secure fixing.

Needs to be brought up with whoever’s running the job.
Has this been rewired? Is it two brown cables there, or black?

Brass bush at the box hole… so maybe it is steel conduit.
Still doesnt make sense to just hang the earthwire off a screw.

It's a brown and a black cable, the screw with the earth on it just screws into the little lug on the side of the backbox to hold the face plate/light switch on. If the screw is removed, the earth is just left hanging, not connected to anything

 

[PS Electrics]

tView attachment 123001

You have to laugh I guess when you see something like this.

Thanks for posting the picture it will be as LittleSpark said. It is a conduit system.

I guess we have to assume the conduit doesn't provide any earthing hence why they have run in a cpc?

So as per LittleSpark said it could be fixed to the vertical lugs on the box if they are usable that at least would be a secure connection.

Or drill and tap the back box and fit a Earth Terminal or post to connect into like he said.

What they have done isn't acceptable because that connection will likely not be tight when the accessory is screwed back.

Nothing to lose any sleep over and quite easily fixed but they should change it.

 

[Azrael]

You have to laugh I guess when you see something like this.

Thanks for posting the picture it will be as LittleSpark said. It is a conduit system.

I guess we have to assume the conduit doesn't provide any earthing hence why they have run in a cpc?

So as per LittleSpark said it could be fixed to the vertical lugs on the box if they are usable that at least would be a secure connection.

Or drill and tap the back box and fit a Earth Terminal or post to connect into like he said.

What they have done isn't acceptable because that connection will likely not be tight when the accessory is screwed back.

Nothing to lose any sleep over and quite easily fixed but they should change it.

If that is how they are fixing the Earth in the light switches, they could also be doing that in all the sockets, as well. There are many switches/sockets in just one flat, 56 flats in one high-rise, and 7 high-rises; that's a lot of unsecured sockets/switches. Would you say this is totally unacceptable. I don't want to be a complete Karen but it seems pretty amateurish to me and if any screw falls out could this be a hazard

 

[mainline]

You have to laugh I guess when you see something like this.

Thanks for posting the picture it will be as LittleSpark said. It is a conduit system.

I guess we have to assume the conduit doesn't provide any earthing hence why they have run in a cpc?

So as per LittleSpark said it could be fixed to the vertical lugs on the box if they are usable that at least would be a secure connection.

Or drill and tap the back box and fit a Earth Terminal or post to connect into like he said.

What they have done isn't acceptable because that connection will likely not be tight when the accessory is screwed back.

Nothing to lose any sleep over and quite easily fixed but they should change it.

It could have been changed from metal to plastic, hence the bodge.

 

[PS Electrics]

If that is how they are fixing the Earth in the light switches, they could also be doing that in all the sockets, as well. There are many switches/sockets in just one flat, 56 flats in one high-rise, and 7 high-rises; that's a lot of unsecured sockets/switches. Would you say this is totally unacceptable. I don't want to be a complete Karen but it seems pretty amateurish to me and if any screw falls out could this be a hazard

Yes it is unacceptable and that does make you wonder about other parts of the installation.

Is this a full rewire? I assumed they may have run just the cpc in due to no earthing? The colours concern me if new they should both be brown cables, though it would still be compliant if they identify the cable, this can be done with sleeving.

From the photo it doesn't look like they have done that, marked the black cable with brown sleeving or tape?

Not so much of an issue at the switch because we know its not a neutral but may cause an issue at the lights when the next person comes to work on it. (Black was the neutral in the old colours)

Little things but when you see things like this it makes you wonder about the quality of the job!

 

[Azrael]

Just wanted to say thank you to you guys for your help and advice, it was really much appreciated. You're TOP MEN

 

[PS Electrics]

Just wanted to say thank you to you guys for your help and advice, it was really much appreciated. You're TOP MEN

Thanks

Would also add there is a bit too much copper showing on those terminations, really the insulation should go right up to the termination so you see no copper.

Can easily see a scenario where that earth lug comes into contact with that when the faceplate is removed.

 

[littlespark]

Is this in Glasgow as your profile suggests?

it’s ridiculous that this is what they’re doing.

It’s like someone’s asked a first year apprentice to “just crimp the green, and use the fixing screw”
Wrong screw, matey.

When it comes to final testing, they’ll get a good reading, as it’s going through the conduit as well… never be noticed.


There may be no point bringing it to the attention of the sparks on the job, or their immediate supervisors if all the same company… There should be a clerk of works for the housing association though.

 

[westward10]

Back box looks like it has four lugs just screw it secure to one of the others.

 

[mainline]

Back box looks like it has four lugs just screw it secure to one of the others.

To add to that, it would have to be to a fixed one.

 

[littlespark]

Back box looks like it has four lugs just screw it secure to one of the others.

You could, but like it was said earlier, a standard 3.5 screw may not be threaded all the way... so once it gets to what should be tight.... the threads slip off and just spins.

There might be a screw in the back of the box fixing it to the wall that could be used, but best practice is drill and tap.


Now I'm on PC rather than teeny tiny phone screen.... it looks like the crimp has ben squashed up with a pair of snips rather than a crimper. Although i might be wrong...

 

[mainline]

You could, but like it was said earlier, a standard 3.5 screw may not be threaded all the way... so once it gets to what should be tight.... the threads slip off and just spins.

There might be a screw in the back of the box fixing it to the wall that could be used, but best practice is drill and tap.


Now I'm on PC rather than teeny tiny phone screen.... it looks like the crimp has ben squashed up with a pair of snips rather than a crimper. Although i might be wrong...

Could use a suitable nut.

 

[westward10]

You could, but like it was said earlier, a standard 3.5 screw may not be threaded all the way... so once it gets to what should be tight.... the threads slip off and just spins.

There might be a screw in the back of the box fixing it to the wall that could be used, but best practice is drill and tap.


Now I'm on PC rather than teeny tiny phone screen.... it looks like the crimp has ben squashed up with a pair of snips rather than a crimper. Although i might be wrong...

It does look like side cutters have done that.

 

[littlespark]

Could use a suitable nut.

yes... to space the screw so the threads are still holding.... but might be too much to get the plate back on the wall.

Not ideal when there is a better alternative of drilling and tapping.

Did a lot of rewiring of old farm houses as an apprentice, back in the 90's... drilling and tapping the boxes... and metal toggle plates had earth pigtails soldered onto the back of them, and brasso'ed up to look shiny