No earth cable on light fitting

[EFLImpudence]

Are you suggesting that they are simply saying exactly the same as me - that, in general (and whether it is an electrical product or not), avoidance of any earthed metal is desirable

Yes

or are you suggesting (which I would find more difficult to understand) that they feel that it could/would in some way impair the safety of the product itself?

No. I don't think generally it impacts at all on the product.

 

[JohnW2]

Yes - but much as you and I would agree that it would, on balance, be better not to earth it, would you actually use the words "must not"?

Yes if I had installed it so that was the case. Do you expect a sticker to state a long drawn out explanation full of ifs and buts?

No - but knowing that there are at least some people who would feel that it should be earthed, I would probably regard it as inappropriate and
'arrogant' (and probably still would do if I were an electrical professional) to say "must not".

Kind Regards, John

 

[EFLImpudence]

No - but knowing that there are at least some people who would feel that it should be earthed, I would probably regard it as inappropriate and 'arrogant' (and probably still would do if I were an electrical professional) to say "must not".

Not sure I understand your reasoning. It shouldn't be earthed.

I would think that the very reason to place a "must not be earthed" sticker.

Do you want it to say "Please don't earth, call O1XX2 123456 if you don't know what you're doing"?

 

[JohnW2]

Not sure I understand your reasoning. It shouldn't be earthed. I would think that the very reason to place a "must not be earthed" sticker.

If you are absolutely certain and 100% confident in your view that it should not be earthed, then that's probably the correct course.

All I'm saying is that, knowing that at least some people would disagree, I personally would not feel it appropriate for me to make such an dogmatic/assertive statement. I guess we differ.

Kind Regards, John

 

[PBC_1966]

You could look around your home and see how many Class II items you have, and then determine how many of them have exposed metal parts - I doubt that it would be many, if any.

The audio-visual equipment already discussed is probably the most common in homes: VCR's, DVD players, satellite receivers, audio amplifiers, etc.

 

[ban-all-sheds]

All I was trying to say is that if class I appliances with earthed casings are allowed, it makes no sense to say that you can't earth the casing of what would otherwise be a class II appliance. If the latter somehow creates an unacceptable risk due to some possible external fault, then surely so does the former?

No, because the former is there to ensure that the OPD operates if the case should become live due to a fault within the item.

 

[ban-all-sheds]

You install a class II light fixture, for example, but bolt an earth onto the metalwork anyway. How is the result any different than if you'd just chosen to use a class I fixture instead? Either way you end up with a light fixture on the wall or ceiling which has earthed metalwork.

Because you have introduced a hazard which was not there before.

 

[ban-all-sheds]

We seem to be talking as if Class II equipment with exposed metal is common, but that is not my experience. I would think that the majority of Class II products I see are 'all plastic'

I have wall lights which are metal and Class II.

And there are plenty of metal lights here: www.double-insulated-lighting.co.uk

 

[ban-all-sheds]

(particularly given that, as we know, there are at least some people who sincerely believe that, on balance, it is better to earth it)

Some people sincerely believe things as bizarre as the world is flat, that the US govt blew up the WTC, that Donald Trump would make a good president, that a cosmic Jewish Zombie who was his own father can make you live forever if you symbolically eat his flesh and telepathically tell him you accept him as your master so he can remove an evil force from your soul that is present in humanity because a rib-woman was convinced by a talking snake to eat from a magical tree, or that the UK would be better off if it left the EU.

 

[PBC_1966]

All I was trying to say is that if class I appliances with earthed casings are allowed, it makes no sense to say that you can't earth the casing of what would otherwise be a class II appliance. If the latter somehow creates an unacceptable risk due to some possible external fault, then surely so does the former?

No, because the former is there to ensure that the OPD operates if the case should become live due to a fault within the item.

We were talking about possible risk due to some external fault making the casing live. That wll be the same (minimal) risk in either case.

 

[EFLImpudence]

We were talking about possible risk due to some external fault making the casing live. That wll be the same (minimal) risk in either case.

When one of them was zero before you earthed it.

Why do you WANT to earth things which do not require it?

Put some metal bits on you plastic accessories then you can earth them as well.

 

[Taylortwocities]

Why do you WANT to earth things which do not require it?

Because Winston says that one should. I have warned him about this before

 

[PBC_1966]

Why do you WANT to earth things which do not require it?

I'm not saying that I do. I'm saying that if one does earth the metal casing of a double-insulated device, the result is no worse than if you'd used a device which was not double-insulated and required earthing for safety. And I'm saying that just because something is double-insulated there might still be reasons for wanting to earth it anyway in certain circumstances.

 

[ban-all-sheds]

I'm saying that if one does earth the metal casing of a double-insulated device, the result is no worse than if you'd used a device which was not double-insulated and required earthing for safety.

Of course it is worse.

If you earth the metal case of Class II device it is less safe than it would be if you left it alone. Less safe is not "no worse".

And I'm saying that just because something is double-insulated there might still be reasons for wanting to earth it anyway in certain circumstances.

Ignorance... superstition... fear... perversity...

 

[PBC_1966]

Of course it is worse.

If you earth the metal case of Class II device it is less safe than it would be if you left it alone. Less safe is not "no worse".

You're ignoring the rest of my statement: I said no worse than if you'd used a device which was not double-insulated.

Ignorance... superstition... fear... perversity...

Screening, reducing problems caused by cumulative capacitance resulting in excessive leakage currents.....