Earthing Spike

[RF Lighting]

No, because plugs are used for EARTHING, not bonding.

It really is time you learnt the difference, when and why each is required.

 

[EFLImpudence]

So do you think are the plugs with E marked on the should have it changed to B?

No.


However, when the redundant electrode is left connected (when TN-C-S is installed) why does it not bond the ground?

 

[ericmark]

OK if the yellow and green wire goes to electrical equipment it is an earth wire and if it goes to non electrical equipment it is a bonding wire. In theroy you can bond without connecting to earth and I suppose there must be a case where class II equipment only is used so the metal is only bonded although I can't think of an example.

In theroy if the earth rods are 0.05 ohm then even if the neutral is lost on a 100A supply the earth will not rise to over a 50 volt point. However the DNO need only have a 21 ohm earth so it would be pointless to have a homes earth better than the DNO earth and with both at 21 ohm then 1.2 amp is the maximum current at which you could expect a fuse to protect. Or 2.4 amp if the home got zero ohms. Neither are practical.

However I would think you could use something like the old ELCB-v if you wanted to disconnect the supply should the supply earth become 50 volt away from the earth electrode, but it would need to be installed in every house to ensure the DNO supply did not have a earth to real earth voltage over 50 volt. To introduce a system like that because of the few times the DNO lost the earth neutral would be like insisting on metal consumer units because some were incorrectly installed and went on fire.

 

[PBC_1966]

I really don't understand the fuss which is made by some people these days if somebody talks about earthing, say, a metal bathtub, and gets told "It's not earthing, it's bonding."

Yes, you can bond two things together without earth being involved in any way. But if you bond something to an earth connection, then you've earthed it. Even the Wiring Regs. used to talk about earthing tubs, pipework, etc.

 

[ban-all-sheds]

http://www.diynot.com/diy/search/3631145/?q=cockburn&o=relevance&c[node]=8

 

[EFLImpudence]

I really don't understand the fuss which is made by some people these days if somebody talks about earthing, say, a metal bathtub, and gets told "It's not earthing, it's bonding."

That's because it is bonding; not earthing.

Yes, you can bond two things together without earth being involved in any way.

You physically can but you should not and it will achieve nothing.
If they are not already earthed in any way then they will not require bonding.

But if you bond something to an earth connection, then you've earthed it.

Yes, but you have bonded it to equalise the potential difference; not so that an OPD will operate.
That is the reason for the two terms; so we know what is meant.

Even the Wiring Regs. used to talk about earthing tubs, pipework, etc.

Times and terms change.

 

[PBC_1966]

I really don't understand the fuss which is made by some people these days if somebody talks about earthing, say, a metal bathtub, and gets told "It's not earthing, it's bonding."

That's because it is bonding; not earthing.

You are connecting it to earth. How is that not earthing?

Yes, you can bond two things together without earth being involved in any way.

You physically can but you should not and it will achieve nothing.

Not so. There are plenty of instances in radio-frequency work in which you might want to bond two things together without them being earthed,

But if you bond something to an earth connection, then you've earthed it.

Yes, but you have bonded it to equalise the potential difference; not so that an OPD will operate.
That is the reason for the two terms; so we know what is meant.

But if something live were to contact the item which has been bonded (to earth), the protective device would operate anyway.

Times and terms change.

The laws of physics don't though.

 

[EFLImpudence]

I really don't understand the fuss which is made by some people these days if somebody talks about earthing, say, a metal bathtub, and gets told "It's not earthing, it's bonding."

That's because it is bonding; not earthing.

You are connecting it to earth. How is that not earthing?

The purpose is to equalise potential. That is bonding. Simples.

Yes, you can bond two things together without earth being involved in any way.

You physically can but you should not and it will achieve nothing.

Not so. There are plenty of instances in radio-frequency work in which you might want to bond two things together without them being earthed,

I am talking about electrical installations.

But if you bond something to an earth connection, then you've earthed it.

Yes, but you have bonded it to equalise the potential difference; not so that an OPD will operate.
That is the reason for the two terms; so we know what is meant.

But if something live were to contact the item which has been bonded (to earth), the protective device would operate anyway.

That is true but not the reason for it.

Times and terms change.

The laws of physics don't though.

...but what we call them does.

 

[JohnW2]

I really don't understand the fuss which is made by some people these days if somebody talks about earthing, say, a metal bathtub, and gets told "It's not earthing, it's bonding."

That's because it is bonding; not earthing.

You are connecting it to earth. How is that not earthing?

The purpose is to equalise potential. That is bonding. Simples.

I'm a bit lost here. When people like Bernard want an (otherwise 'floating') metal bath to be 'connected' to the CPC system, the reason given is usually that it facilitates operation of a protective device if/when some drops the infamous hairdryer into a bath full of water and persons.

That's surely earthing, not bonding?

Kind Regards, John

 

[JohnW2]

In theroy if the earth rods are 0.05 ohm then even if the neutral is lost on a 100A supply the earth will not rise to over a 50 volt point.

Did you perhaps mean 0.5Ω ??

Kind Regards, John

 

[EFLImpudence]

I'm a bit lost here.

I don't think you are.

When people like Bernard want an (otherwise 'floating') metal bath to be 'connected' to the CPC system, the reason given is usually that it facilitates operation of a protective device if/when some drops the infamous hairdryer into a bath full of water and persons.
That's surely earthing, not bonding?

Well, yes. Would it do that?


I was taking the question to mean (as it was) when people were talking about actual required bonding and wrongly calling it earthing.

Wrongly applied bonding (when NOT required) is indeed earthing.

 

[JohnW2]

When people like Bernard want an (otherwise 'floating') metal bath to be 'connected' to the CPC system, the reason given is usually that it facilitates operation of a protective device if/when some drops the infamous hairdryer into a bath full of water and persons. That's surely earthing, not bonding?

Well, yes. Would it do that?

Would it do what - facilitate operation of a protective device? It would certain trip an RCD, if there were one in the supply to the hairdryer, but it probably wouldn't cause an OPD to operate (anless some life part of dryer came in contact with bath, rather than just the water) - does that qualify as 'earthing' in your book?

I was taking the question to mean (as it was) when people were talking about actual required bonding and wrongly calling it earthing.

That's not how I interpreted PBC's comment/question to which you were responding. Apart from anything else, neither bonding nor earthing of a 'floating' bath is ever required.

Kind Regards, John

 

[ban-all-sheds]

I'm a bit lost here. When people like Bernard want an (otherwise 'floating') metal bath to be 'connected' to the CPC system, the reason given is usually that it facilitates operation of a protective device if/when some drops the infamous hairdryer into a bath full of water and persons.

That's surely earthing, not bonding?

It is, which is why it should not be done - the bath is not an exposed-conductive-part.

 

[ban-all-sheds]

Wrongly applied bonding (when NOT required) is indeed earthing.

Not necessarily - if you had two metal baths and you connected them together you would have bonded them, but not earthed them.

 

[EFLImpudence]

That's not how I interpreted PBC's comment/question to which you were responding. Apart from anything else, neither bonding nor earthing of a 'floating' bath is ever required.

Ok. undoubtedly he will tell us.

However:

I really don't understand the fuss which is made by some people these days if somebody talks about earthing, say, a metal bathtub, and gets told "It's not earthing, it's bonding."

If you are correct, then they would not be told "It's not earthing, it's bonding", would they?

The problem would then be people who are referring to earthing as bonding by mistake - not generally the case.



Anyway, when he wakes up, he will probably think of something to continue your hyper-hair-splitting debates of recent.

I do get the impression he is a bit of a wind-up merchant.