Earthing Spike

[JohnW2]

However, it would depend on an on-site assessment of the individual situation.

as well as consideration of the way the kitchen would or could be used ...

That's obviously a crucial part of the 'assessement of the individual situation'

...and a sensible interpretation of the book(s) of rules.

I'm not too sure which "books of rule(s)" have much specific or explicit to say about this issue.

... maybe the taps linked by copper pipe connect the work tops but then the supply to the kitchen is in plastic pipe. ( hence the water pipes are bonding the work tops together but not earthing them ).

That's one of the many issues which would be consdiered but, off the top of my head, I doubt I would consider that as materially different from the situation in which the taps/worktops were not connected (and none of it earthed).

What if the taps are bonded via pipe work to the MET and not in contact with the work tops. Potential difference between taps and un-bonded / earthed work top could be enough to tingle due to a class two appliance capacitively coupling 115 volts to the work top.

... that's another consideration to go into the 'risk assessment melting pot'. I'm not too worried about that possibility of 'tingles' (which would very probably not happen), but the presence of earthed taps in the proximity of the extensive (unearthed) metal of the worktops would certainly be a major factor which would go into my melting pot.

And placing an earthed metal appliance on one work top would "earth" that work top but only when the appliance was plugged in to a socket.

More for the melting pot! I'm not sure that I'd get too excited about this one - we are discussing/debating two possible approaches (neither of which is outrageous/unacceptable) and, if the decision were to not earth the worktops, all that would happen in your scenario is that one would temporarily switch to the other approach.

You haven't said so yet, but do I take it that you would probably favour earthing the worktops, in almost any situation?

Kind Regards, John

 

[RF Lighting]

What about all the cutlery? The tins of spam? The front door key?

 

[JohnW2]

What about all the cutlery? The tins of spam? The front door key?

Indeed - but, to be serious, I think that he worktops present a situation which requires appreciably more thought.

I doubt that there are many situations in which I would feel it appropriate to earth (otherwise unearthed) worktops, but I couldn't say that there would never be circumstances in which I would consider that to be 'the lesser of evils'.

Kind Regards, John

 

[ban-all-sheds]

Indeed - but, to be serious, I think that he worktops present a situation which requires appreciably more thought.

Not really.

You either think that it's a good idea to make worktops and tables part of the electrical installation, or you think that it is not. Positions which either don't require much thinking about or which cannot be arrived at if you do think about it.

 

[JohnW2]

You either think that it's a good idea to make worktops and tables part of the electrical installation, or you think that it is not.

It's clearly not desirable that worktops should "become part of the electrical installation". However, if (exceptionally) one judged that there was a significant risk that it could accidentally "become of the electrical installation" (and maybe a part which was not close to earth potential!) then there might be a case for considering pre-emptive measures!

However, as I said before, I doubt that such a situation would often, if ever, arise.

Kind Regards, John

 

[PBC_1966]

You either think that it's a good idea to make worktops and tables part of the electrical installation, or you think that it is not.

"Made part of the electrical installation" in the sense of connecting them to the earth of that installation? That can happen inadvertently anyway by simply resting some other metal-cased earthed appliance on them. What if I'm fitting some kitchen cupboards or shelves and lay a drill down on the sink? What if an earthed cooker is pushed up against the edge of a sink unit?

 

[EFLImpudence]

Do you genuinely not understand?

"Made part of the electrical installation" in the sense of connecting them to the earth of that installation?

Yes.

That can happen inadvertently anyway by simply resting some other metal-cased earthed appliance on them.

In the lack of plastic feet - so what?

What if I'm fitting some kitchen cupboards or shelves and lay a drill down on the sink?

What if you do?

What if an earthed cooker is pushed up against the edge of a sink unit?

What if it is?

 

[JohnW2]

Do you genuinely not understand?

I think he understands - he was really just repeating what I wrote to BAS in my previous message - that something can "become part of the electrical system" 'accidentally', as well as the result of deliberately connecting it with a cable.

I agree that, in most cases, the appropriate response to that is "so what?", but that doesn't make it any less true.

Kind Regards, John

 

[PBC_1966]

Exactly. Unless you make sure that everything else which might be used around a sink, bathtub etc. doesn't have exposed earthed metalwork, then you can't avoid the possibility of it ending up earthed by incidental contact at some point in time.

 

[EFLImpudence]

Do you genuinely not understand?

I think he understands

So do I.

I think it is just a question of fatuous questions - winding-up.

Exactly. Unless you make sure that everything else which might be used around a sink, bathtub etc. doesn't have exposed earthed metalwork, then you can't avoid the possibility of it ending up earthed by incidental contact at some point in time.

It doesn't matter. Just don't make that the permanent situation.

 

[ban-all-sheds]

I think he understands

He gives no indication that he understands the difference between doing something on purpose and that thing happening by accident.

 

[JohnW2]

Exactly. Unless you make sure that everything else which might be used around a sink, bathtub etc. doesn't have exposed earthed metalwork, then you can't avoid the possibility of it ending up earthed by incidental contact at some point in time.

Indeed, but my point was that the risk-assessment needs to go further than that, since (exceptionally) 'earth' might not be the "part of the electrical installation" which one thought might come in contact with the metal object!

We've had this discussion before in relation to a metal worktop on a workbench, used perhaps for welding or for electronics work. In that situation, it is (IMO) far more difficult to decide which is the "lesser of the evils".

Kind Regards, John