No earth cable on light fitting

[JohnW2]

You two (J & P) really are labouring this unnecessarily especially as you have answered the question in your post.

If only everyone would just agree that all we're talking about is the general undesirability of having 'necessarily earthed' metal around one's house (something I am always saying), then there would be nothing to discuss/debate.

However (and maybe I'm misinterpreting what people are saying), there seems to be an implication that there is something 'special' about a Class II electrical item, such that it is in some sense 'worse' ('less safe') to ('unnecessarily') earth the exposed metal of a Class II electrical item than it is to ('unnecessarily') earth a metal worktop, bath, window frame or whatever - and I have yet to see any reason to agree with that.

Kind Regards, John

 

[EFLImpudence]

However (and maybe I'm misinterpreting what people are saying), there seems to be an implication that there is something 'special' about a Class II electrical item, such that it is in some sense 'worse' ('less safe') to ('unnecessarily') earth the exposed metal of a Class II electrical item than it is to ('unnecessarily') earth a metal worktop, bath, window frame or whatever - and I have yet to see any reason to agree with that.

I don't think anyone has said that.

 

[JohnW2]

However (and maybe I'm misinterpreting what people are saying), there seems to be an implication that there is something 'special' about a Class II electrical item, such that it is in some sense 'worse' ('less safe') to ('unnecessarily') earth the exposed metal of a Class II electrical item than it is to ('unnecessarily') earth a metal worktop, bath, window frame or whatever - and I have yet to see any reason to agree with that.

I don't think anyone has said that.

As I said, maybe I've been misinterpreting what people have been saying, believing their comments to be specific to Class II electrical appliances.

As I also said, if all they are doing is agreeing with me that unnecessarily earthing touchable metal is undesirable (whether that metal be a worktop, bath, Class II electrical item or whatever), then it would seem that we are all in agreement.

Kind Regards, John

 

[ban-all-sheds]

[That I don't understand. It will make the environment (very slightly) 'less safe', by unnecessarily introducing more touchable earthed metal (just as, for example, if one unnecessarily earthed a metal worktop, metal window frame, metal bath etc. etc.), but I don't see how it can make the item itself any less safe.

Surely the environment is less safe because things within it have become less safe. For example unnecessarily earthed metal worktops, metal window frames, metal baths etc.

 

[JohnW2]

Surely the environment is less safe because things within it have become less safe. For example unnecessarily earthed metal worktops, metal window frames, metal baths etc.

As I've just written, if that is all that people are saying, then I think we are all in agreement.

There are, of course, a few who would disagree, at least in some cases, but none of them seem to have participated in this discussion.

I'm still inclined to feel that, given that there are some contrary views, to assert that one "must not" ('unnecessarily') earth a metal worktop, metal bath, Class II electrical item etc. is probably not really appropriate.

Kind Regards, John

 

[EFLImpudence]

I'm still inclined to feel that, given that there are some contrary views, to assert that one "must not" ('unnecessarily') earth a metal worktop, metal bath, Class II electrical item etc. is probably not really appropriate.

To say one "must not" ('unnecessarily') earth an item would seem to be very appropriate.

If the other metal items, as is the case with Class II items, cannot come into contact with live conductors and are not exposed-c-ps (nor extraneous-c-ps (for bonding)) then "must not" is very appropriate.

 

[JohnW2]

To say one "must not" ('unnecessarily') earth an item would seem to be very appropriate.

That would be true if everyone agreed that it was 'unnecessary'. However, as we know, that is not the case, at least in relation to some items.

If the other metal items, as is the case with Class II items, cannot come into contact with live conductors and are not exposed-c-ps (nor extraneous-c-ps (for bonding)) then "must not" is very appropriate.

Again, IMO, only if that were a universal view.

It's obviously not very appropriate for me to make any such assertions in relation to electrical matters, but even in fields in which I am highly qualified and experienced, I would not make an unqualified "must not" assertion if I knew that there were sane people who would disagree with the statement. However, that's somewhat of a personal view - I accept that some people often make 'assertions' about things which are only personal views!

Kind Regards, John

 

[ban-all-sheds]

even in fields in which I am highly qualified and experienced, I would not make an unqualified "must not" assertion if I knew that there were sane people who would disagree with the statement.

Even if they were wrong, which they could be, even if sane?

 

[JohnW2]

even in fields in which I am highly qualified and experienced, I would not make an unqualified "must not" assertion if I knew that there were sane people who would disagree with the statement.

Even if they were wrong, which they could be, even if sane?

Probably yes - since, unlike some people, I would not usually assume that just because I believed them to be wrong that they necessarily were wrong.

I should have perhaps clarified that when I spoke of "sane people" I was talking about those with adequate knowledge and/or education and/or qualifications and/or experience for their views on the matter to be taken seriously.

Kind Regards, John

 

[EFLImpudence]

To say one "must not" ('unnecessarily') earth an item would seem to be very appropriate.

That would be true if everyone agreed that it was 'unnecessary'. However, as we know, that is not the case, at least in relation to some items.

As you included unnecessarily, albeit unnecessarily in brackets, the answer is that you must not.
If someone disagrees that it is unnecessary then it must be necessary - which it is not.

If the other metal items, as is the case with Class II items, cannot come into contact with live conductors and are not exposed-c-ps (nor extraneous-c-ps (for bonding)) then "must not" is very appropriate.

Again, IMO, only if that were a universal view.

It should be with the conditions I included.

On the other hand, for metal items which, as is the case with Class I items, can come into contact with live conductors and are exposed-c-ps (and extraneous-c-ps (for bonding)) would you also think it unwise to state that earthing "must not" be omitted just because someone may have a different view.

Are subjects which are not open to different views, i.e. facts, to be similarly treated?

Probably yes - since, unlike some people, I would not usually assume that just because I believed them to be wrong that they necessarily were wrong.

I know you have unbelievable tolerance of others but there are obviously occasions when their, not views, but mistaken beliefs are just downright wrong do you still think they may be right?
If not, you have to draw a line somewhere and know you are right and they are wrong.

 

[JohnW2]

As you included unnecessarily, albeit unnecessarily in brackets, the answer is that you must not.

As a generalisation, that obviously not true. There are countless things which are 'not necessary' but without there being any reason for saying that they 'must not' be done.

On the other hand, for metal items which, as is the case with Class I items, can come into contact with live conductors and are exposed-c-ps (and extraneous-c-ps (for bonding)) would you also think it unwise to state that earthing "must not" be omitted just because someone may have a different view.

OK - I need to qualify/refine my position a little. I am talking about the situation in which the 'different view' is (to the best of my knowledge and understanding) 'credible' or 'arguable' - which, in the example you give, it is not ....

I know you have unbelievable tolerance of others but there are obviously occasions when their, not views, but mistaken beliefs are just downright wrong do you still think they may be right?

Indeed, as above. If the 'different view' is, to the best of my knowledge and understanding, neither 'credible' nor 'arguable', then I will 'draw the line' and declare it to be "wrong". However, that's not generally the case in relation to the sort of matters we are talking about. Take the metal bath example - the two different 'views' depend upon a judgement as to which is the more likely of two (both incredibly unlikley) scenarios, so it's difficult to say that either view is 'wrong'.

Kind Regards, John

 

[EFLImpudence]

As you included unnecessarily, albeit unnecessarily in brackets, the answer is that you must not.

As a generalisation, that obviously not true. There are countless things which are 'not necessary' but without there being any reason for saying that they 'must not' be done.

We are not talking about countless things.

On the other hand, for metal items which, as is the case with Class I items, can come into contact with live conductors and are exposed-c-ps (and extraneous-c-ps (for bonding)) would you also think it unwise to state that earthing "must not" be omitted just because someone may have a different view.

OK - I need to qualify/refine my position a little. I am talking about the situation in which the 'different view' is (to the best of my knowledge and understanding) 'credible' or 'arguable' - which, in the example you give, it is not ....

So "must not" is appropriate.

I know you have unbelievable tolerance of others but there are obviously occasions when their, not views, but mistaken beliefs are just downright wrong do you still think they may be right?

Indeed, as above. If the 'different view' is, to the best of my knowledge and understanding, neither 'credible' nor 'arguable', then I will 'draw the line' and declare it to be "wrong". However, that's not generally the case in relation to the sort of matters we are talking about.

We are talking about earthing items which must be earthed and not earthing items which must not be earthed.

Take the metal bath example - the two different 'views' depend upon a judgement as to which is the more likely of two (both incredibly unlikley) scenarios, so it's difficult to say that either view is 'wrong'.

In the example I quoted of an isolated bath, it is not dependent on judgement.

 

[JohnW2]

So "must not" is appropriate.

As I said, in the example you gave, in which (AFAICS) any different view is not credible/arguable, then I agree.

Take the metal bath example - the two different 'views' depend upon a judgement as to which is the more likely of two (both incredibly unlikley) scenarios, so it's difficult to say that either view is 'wrong'.

In the example I quoted of an isolated bath, it is not dependent on judgement.

Bernard would presumably disagree, and I doubt that he is alone. You and I feel that unnecessarily converting that floating/isolated bath into a mass of earthed metal creates an additional hazard (e.g. if someone simultaneous touches the damaged lead of a vacuum cleaner and that bath). Bernard will cite the possibility of someone dropping a live hair dryer (presumably fed by an extension lead!) into a bath full of water in which they are lying, after which they step out of the bath, and touch a nearby basin tap (or other earthed object) whilst still having one foot in the bath. Both are incredibly unlikely scenarios, but neither is impossible. Which of those two possible scenarios one uses as the basis of one's decision-making is "dependent upon judgement".

Kind Regards, John

 

[stillp]

The bath is not an electrical device though, so although it might be an interesting example of a conductive object, it is neither Class I nor Class II.
Class II equipment is often not designed to withstand a continuous earth potential on its exposed metalwork, and is not designed so that its exposed metalwork can safely carry fault current until a protective device can operate.

 

[PBC_1966]

Even if this is not the case I would earth it anyway as the sum of the leakage currents can cause a tingle."

Nobody but the two of us seems at all interested in the issue of cumulative capacitance when multiple units are interconnected.

earthing a Class II one makes it less safe. .

In some cases, depending upon the circumstances of the fault (internal or external). But there are certainly cases in which earthing a class II device anyway undoubtedly increases safety.