Main bonding diagram

[EFLImpudence]

I am not sure if it's worth showing the connection between true earth and the MET.

It's not that it's between TE and MET but just that the pipes are connected to the CPCs.

Also true earth is a bit of a misnomer, as there's only local earth which may vary significantly from other local earths. But I'm not sure how you'd indicate that,

What should I call it?

maybe a brown resistor symbol between the supplied earth and the ecps?

I don't want to get too complicated.
It's just for showing DIYers when they ask "I have a pipe, does it need bonding?".

 

[John D v2.0]

It's not that it's between TE and MET but just that the pipes are connected to the CPCs.

Ah sorry, I meant maybe it's worth showing that the met is connected to the supplied earth (which is connected to a local earth somewhere via some lowish impedence), as at present it isn't indicated at all.

What should I call it?

Not sure, maybe just write "earths" with a note (may not all be at the same voltage due to ground currents)
As you say, you need the pertinent information without leaving anything essential out or being wrong, but without confusing the issues.

 

[EFLImpudence]

Ah sorry, I meant maybe it's worth showing that the met is connected to the supplied earth (which is connected to a local earth somewhere via some lowish impedence), as at present it isn't indicated at all.

Ah, that is a good idea. Thanks.

 

[ban-all-sheds]

I don't agree about the CPCs.

This isn't for electricians but DIYers and to explain why it needs bonding and/or is already earthed.

Yes, but what happens to a pipe once inside the house, whether it goes to a tap or to a Class I electrical appliance (which even then may not create a connection between cpc and pipe) has no bearing on the need for main bonding.

 

[EFLImpudence]

View attachment 128848

Yes, but what happens to a pipe once inside the house, whether it goes to a tap or to a Class I electrical appliance (which even then may not create a connection between cpc and pipe) has no bearing on the need for main bonding.

No, I know and agree.

I am try to show DIYers why - or why not - and the difference between various methods and pipe installations.

Is it the title that is wrong? Should I not bother?

 

[EFLImpudence]

Anyway, latest version.

 

[EFLImpudence]

 

[ban-all-sheds]

Well, they may care because they are trying to understand what is the situation and why measurements can vary and because that is how their installation is likely to be which is the purpose of my diagram.

As far as being irrelevant to bonding:
It will appear to indicate that a pipe is an extraneous-c-p when it might not be or that a pipe is bonded when it is not.
A true determination cannot be made without disconnecting any CPC connections, so not knowing that they may exist would presumably be a disadvantage.

Do DIYers do these measurements and determinations?

Isn't it simpler to just talk about the requirements for main bonding (or "connecting to earth") of incoming pipes if they are metal but not if they are plastic, and leave it there?

A metal pipe does not need main bonding because a cpc earths it somewhere, and the recent example of confusion arose because someone wrongly thought that a metal pipe should be earthed in case a damaged cable made it live.

I fear that most DIYers won't have a clue what your diagrams are showing. Sorry.

I think the problem is that whilst it is easy to show when main bonding is, or is not, required, you are straying into trying to explain in pictures the difference between earthing and bonding.


Does anybody know what terms are used in other countries?

 

[mwatsonxx]

View attachment 128854

A very amusing diagram, especially 1 and 2, these are direct contradictions of this forum and EFL's constant advice that bonding is not required in bathrooms and kitchens.

 

[ban-all-sheds]

1) is showing an incoming metal pipe correctly bonded.

2) Is showing an incoming plastic pipe correctly not bonded.

There's no mention of either bathrooms or kitchens in the diagrams.

 

[mwatsonxx]

Are you confirming that bonding is not required in bathrooms and kitchens?