Which?

[JohnD]

some time ago I used to read accident reports in the electricity industry.

One (quite unusual) related to a socket where the earthwires had been connected to the backbox, with no flylead.

due to long-term damp, the backbox corroded and rusted, affecting the fixing lugs so that eventuially the screws lost continuity, and the socket and appliance lost their earth.

I don't remember what the other fault was that led to the accident.

Flyleads are so cheap and easy that I see no point in omitting them.

 

[plugwash]

In our kitchen we have the MK brushed steel screwless sockets and switches.

I understand MK aren't what they used to be on quality, and while their white plastic products are quite reasonable their fancy products are very expensive.

I'd look for ones with USB outlets on them.

I wouldn't.

First there is the vampire loads issue. You will end up with a bunch of power supplies permanently connected to the mains whether they are being used or not.

Second there is the issue that chargers are evolving, the chargers inside sockets tend to be behind the curve.

Third there is the issue of failures. If one fails in a dangerous way or in a way that causes the circuit to trip you have a problem that needs to be dealt with urgently.

There are niches where sockets with USB make sense, but using them for a whole installation is madness.

 

[CACKATALLTRADES]

Yes you are quite correct, whoever mounted the socket in such a way that it relied on the mechanical mountings for the safety earth;
all they had to do was do the job better and the ingress of the grease would have been completely harmless.

Please show me where I advocated earthing the socket via the mounting screws. All I have ever advocated at any stage is earthing the socket correctly with the earth wire in the earth terminal.

 

[bernardgreen]

If the face plates are metal they will automatically be earthed via the earth wire screwed into the back, and electrical continuity with the back box will be achieved via the two metal mounting screws. (Assuming they haven't been designed in a way that eliminates the possibility of their becoming live)

That is ambiguous ... It would be better if you had said

If the face plates are metal they will automatically be earthed via the earth wire(s) connected to the Earth terminal on the back of the faceplate, and electrical continuity with the back box might be achieved via the two metal mounting screws provided they remain securely fixed. (Assuming they haven't been designed in a way that eliminates the possibility of their becoming live)

 

[JohnW2]

No need for a fly lead, because if you take the socket off without isolating it the installer is not responsible.

Practices designed to improve safety (in whatever scenarios) are practices designed to improve safety, regardless of who would be responsible if 'less safe' practices had been employed.

 

[blup]

Well, maybe and sort of.

If the faceplates are metal, THEY need to be EARTHED - by connecting them to the earth wire; the back box is irrelevant.

The backbox isn't irrelevant in that good practice indicates it should be additionally earthed by connection to the earth terminal of the socket, mainly, it seems to protect electricians (and others) who might be electrocuted when removing the faceplate and losing the earth connection between screw lug and earth wire.

Blup

 

[EFLImpudence]

The backbox isn't irrelevant in that good practice indicates it should be additionally earthed by connection to the earth terminal of the socket, mainly, it seems to protect electricians (and others) who might be electrocuted when removing the faceplate and losing the earth connection between screw lug and earth wire.

Switch off the supply.


If you want to "earth" the back box, you are perfectly at liberty to do so.

However, it was not correct to say to a DIYer that the faceplate "will need to be earthed to the metal back box".

 

[bernardgreen]

One reason the back box should be earthed by a link to the Earth terminal on the face plate of a plastic switch/

Consider the situation where the insulation on the Live conductor is damaged by a sharp edge of the back box allowing the back box to contact the Live conductor and thus become Live. Not problem ? Not until a finger, possible damp, touches the head of one of the fixing screws.

 

[blup]

Switch off the supply.


If you want to "earth" the back box, you are perfectly at liberty to do so.

However, it was not correct to say to a DIYer that the faceplate "will need to be earthed to the metal back box".

It's as broad as it's long, better the OP understands the need to earth than fits metal faceplates with the associated risks.

Blup

 

[EFLImpudence]

It's as broad as it's long, better the OP understands the need to earth than fits metal faceplates with the associated risks.

Oh dear.

Parts are not earthed by connecting them to a back box.

 

[EFLImpudence]

One reason the back box should be earthed by a link to the Earth terminal on the face plate of a plastic switch/

What?

Consider the situation where the insulation on the Live conductor is damaged by a sharp edge of the back box allowing the back box to contact the Live conductor and thus become Live. Not problem ? Not until a finger, possible damp, touches the head of one of the fixing screws.

Grommetts, OPDs?

Please look at what I have actually written.

 

[bernardgreen]

Grommetts, OPDs?

Grommets are not always fitted. ( they should be but too often are not ).

I have recently come across a switch with Live fixing screws.

Some years ago I was asked to investigate why the wall around a kitchen switch sometimes felt "alive" It was due to damp from condensation and the Switched Live being crushed between the edge of the un-earthed back box and the front plate.

 

[EFLImpudence]

Grommets are not always fitted. ( they should be but too often are not ).

Go on about the lack of grommets, then.

I have recently come across a switch with Live fixing screws.

How did that happen? Where was the CPC?

Some years ago I was asked to investigate why the wall around a kitchen switch sometimes felt "alive" It was due to damp from condensation and the Switched Live being crushed between the edge of the un-earthed back box and the front plate.

Again, where was the CPC?



I still don't understand this -

One reason the back box should be earthed by a link to the Earth terminal on the face plate of a plastic switch/

 

[bernardgreen]

In one case the CPC had been terminated into a terminal block and in the other wrapped in tape.

One reason the back box should be earthed by a link to the Earth terminal on the face plate of a plastic switch/

That was my error mixing up the switch incident with a socket incident.

 

[bolo 2]

Changing all sockets and switches etc……..and there is a choice between stainless steel, brushed steel and chrome plate………which would you go for?

When I raised this thread early this morning, I thought that when I accessed the site this evening, I would get a couple of replies similar to Mottie’s which after editing reads:

In our kitchen we have the MK brushed steel sockets and switches and Mottie continues with a link to Screwfix as follows:
https://www.screwfix.com/p/mk-aspec...shed-stainless-steel-with-black-inserts/252ff

A perfect reply! However, following Mottie’s reply the thread went off at a tangent mainly about the pros and cons of earthing a socket in the kitchen. And while the posts that followed were very interesting, none, apart from Mottie’s, addressed the initial question which asked which would you choose, stainless steel, brushed steel or chrome plated sockets etc. I have enjoyed the cut and thrust of the different points of view regarding earthing but nevertheless would appreciate views on the choice of socket finishes. Thank you