Supplementary bonding

[Happychappy]

Here is a question that I would love tp know your opinion on and honest answers if you do this or not.

Where there is full RCD protection in a domestic property or at least all circuit in the bathroom have RCD protection, how many of you carry out resistance testing on the exposed pipe work to see wheather or not is still requires supplementary bonding? This includes when doing a EICR or alteration and/or additions in a bathroom or just like for like replacements. Do you also carry out these tests for a rewire to check if it needs installing or did you think just by having rcd protection is wasn't required under the 17th edition?

I have asked a fair few qualified electrician about this and most have no idea that if the exsposed pipe work has a resistance of over 1667 ohms it requires supplementary bonding regardless of having full RCD protection.

Your honest answers please

 

[Pete999]

Here is a question that I would love tp know your opinion on and honest answers if you do this or not.

Where there is full RCD protection in a domestic property or at least all circuit in the bathroom have RCD protection, how many of you carry out resistance testing on the exposed pipe work to see wheather or not is still requires supplementary bonding? This includes when doing a EICR or alteration and/or additions in a bathroom or just like for like replacements. Do you also carry out these tests for a rewire to check if it needs installing or did you think just by having rcd protection is wasn't required under the 17th edition?

I have asked a fair few qualified electrician about this and most have no idea that if the exsposed pipe work has a resistance of over 1667 ohms it requires supplementary bonding regardless of having full RCD protection.

Your honest answers please

 

[Nigel]

Here is a question that I would love tp know your opinion on and honest answers if you do this or not.

Where there is full RCD protection in a domestic property or at least all circuit in the bathroom have RCD protection, how many of you carry out resistance testing on the exposed pipe work to see wheather or not is still requires supplementary bonding? This includes when doing a EICR or alteration and/or additions in a bathroom or just like for like replacements. Do you also carry out these tests for a rewire to check if it needs installing or did you think just by having rcd protection is wasn't required under the 17th edition?

I have asked a fair few qualified electrician about this and most have no idea that if the exsposed pipe work has a resistance of over 1667 ohms it requires supplementary bonding regardless of having full RCD protection.

Your honest answers please

It only requires bonding if there is exposed conductive parts within reach and the resistance between the two is higher than 1667 ohms.

I cannot think of many electrical items that would be installed in a shower or bathroom that has exposed conductive parts these days.

 

[Richard Burns]

If there is 30mA RCD protection to all circuits within or passing through the bathroom then one third of the requirements for permitting omission of supplementary bonding are in place.
If, additionally, the circuits meet the requirements for ADS disconnection times and any extraneous conductive parts are correctly bonded to the main earth terminal, then it permissible to omit the supplementary bonding.
Therefore for your question if there are extraneous conductive parts in the bathroom then they must be bonded to the MET, however this is not supplementary bonding it is main protective bonding, which should be a given anyway for an ADS installation.
Simply having metal objects, that are not connected to earth, in a bathroom does not require supplementary bonding, or main bonding.

 

[Leesparkykent]

There is no requirement for supplementary protective equipotential bonding as long as the requirements of (iv), (v) and (vi) of reg 701.415.2 have been satisfied.

Edit: @Richard Burns beat me to it

 

[Happychappy]

If there is 30mA RCD protection to all circuits within or passing through the bathroom then one third of the requirements for permitting omission of supplementary bonding are in place.
If, additionally, the circuits meet the requirements for ADS disconnection times and any extraneous conductive parts are correctly bonded to the main earth terminal, then it permissible to omit the supplementary bonding.
Therefore for your question if there are extraneous conductive parts in the bathroom then they must be bonded to the MET, however this is not supplementary bonding it is main protective bonding, which should be a given anyway for an ADS installation.
Simply having metal objects, that are not connected to earth, in a bathroom does not require supplementary bonding, or main bonding.

No one has actually answered my question though. How many electricians do actually test the exposed pipe work in a bathroom to determine if its just a bit of metal thats not connect to earth or if it is an extraneous conductive part. An RCD will not meet its tripping time if the resistance is above 1667 ohms so without doing the tests you wouldn't know

 

[Happychappy]

There is no requirement for supplementary protective equipotential bonding as long as the requirements of (iv), (v) and (vi) of reg 701.415.2 have been satisfied.

Edit: @Richard Burns beat me to it

Thats not answered my question

 

[Wilko]

Hi - Are you asking does anyone follow the Note at the end of 701.415.2 and actually confirm the effectiveness of the connection of extraneous conductive parts in the bathroom to the MET?
Truthfully, no. I confirm protective bonding to gas and water with wander lead and assume it's carried through the pipework to the bathroom, or if it changes to plastic (say) then that's ok as it's no longer extraneous.

 

[Pete999]

Deleted

 

[Happychappy]

Hi - Are you asking does anyone follow the Note at the end of 701.415.2 and actually confirm the effectiveness of the connection of extraneous conductive parts in the bathroom to the MET?
Truthfully, no. I confirm protective bonding to gas and water with wander lead and assume it's carried through the pipework to the bathroom, or if it changes to plastic (say) then that's ok as it's no longer extraneous.

Thats exactly what I'm asking. Thank you for an honest and straight answer

 

[Happychappy]

It only requires bonding if there is exposed conductive parts within reach and the resistance between the two is higher than 1667 ohms.

I cannot think of many electrical items that would be installed in a shower or bathroom that has exposed conductive parts these days.

1667 ohms is to a known earth not to a another conductive part but that still wasn't my question

 

[Leesparkykent]

No one has actually answered my question though. How many electricians do actually test the exposed pipe work in a bathroom to determine if its just a bit of metal thats not connect to earth or if it is an extraneous conductive part. An RCD will not meet its tripping time if the resistance is above 1667 ohms so without doing the tests you wouldn't know

Thats not answered my question

your question is technically incorrect that’s why you aren’t getting many answers. Your opening post says exposed when really it should say extraneous. You’ve specifically mentioned bathrooms when you should be checking for extraneous conductive parts throughout the whole installation. To answer your question...I bond all extraneous conductive parts back to the MET with an appropriately sized conductor, 30mA RCD protection is provided and my circuits are under max EFLI values then I know my installation is correct. If these 3 points are met then I do not need to worry about supplementary equipotential bonding in the bathroom. You seem to be confused about the actual requirements.... A simplified version of your opening post, would of said “ do you test for extraneous conductive parts that require bonding?”

 

[Nigel]

1667 ohms is to a known earth not to a another conductive part but that still wasn't my question

A known earth within the room. Would you not expect an exposed conductive part to be earthed?

Your question was asked perfectly well. The situation you are describing will only come about once in a blue moon. Certainly I have never came across a bathroom or shower room with an exposed conductive part and extraneous conductive parts within touching distance.

 

[Nigel]

Thats exactly what I'm asking. Thank you for an honest and straight answer

But that is not what you posted. To me as you quoted the 1667 ohms thing which is what is measured between exposed conductive parts and extraneous conductive parts you were asking about that.

You then seem to be complaining that people are not answering a completely different question about what makes a conductive part extraneous.

Which question are you asking?

 

[Happychappy]

A known earth within the room. Would you not expect an exposed conductive part to be earthed?

Your question was asked perfectly well. The situation you are describing will only come about once in a blue moon. Certainly I have never came across a bathroom or shower room with an exposed conductive part and extraneous conductive parts within touching distance.

I

A known earth within the room. Would you not expect an exposed conductive part to be earthed?

Your question was asked perfectly well. The situation you are describing will only come about once in a blue moon. Certainly I have never came across a bathroom or shower room with an exposed conductive part and extraneous conductive parts within touching distance.

Sorry, i meant extraneous conductive part. First time on this forum and really need to get my terminology correct. Thanks for your answer

 

[Happychappy]

But that is not what you posted. To me as you quoted the 1667 ohms thing which is what is measured between exposed conductive parts and extraneous conductive parts you were asking about that.

You then seem to be complaining that people are not answering a completely different question about what makes a conductive part extraneous.

Which question are you asking?

First time on this forum so apologies if I'm not being clear.

My question is who actually carrys out the testing to see if supplementary bonding to extraneous conductive parts in a bathroom is required when there is full RCD protection

 

[Happychappy]

But that is not what you posted. To me as you quoted the 1667 ohms thing which is what is measured between exposed conductive parts and extraneous conductive parts you were asking about that.

You then seem to be complaining that people are not answering a completely different question about what makes a conductive part extraneous.

Which question are you asking?

First time on this forum so apologies if I'm not being clear.

My question is who actually carrys out the testing to see if supplementary bonding to extraneous conductive parts in a bathroom is required when there is full RCD protection

 

[Nigel]

First time on this forum so apologies if I'm not being clear.

My question is who actually carrys out the testing to see if supplementary bonding to extraneous conductive parts in a bathroom is required when there is full RCD protection

Supplymentary bonding is not required for extraneous conductive parts (unless they are within touching distance of exposed conductive parts and the resistance between the two is greater than 1667 ohms) Main equipotential bonding is.

 

[Happychappy]

your question is technically incorrect that’s why you aren’t getting many answers. Your opening post says exposed when really it should say extraneous. You’ve specifically mentioned bathrooms when you should be checking for extraneous conductive parts throughout the whole installation. To answer your question...I bond all extraneous conductive parts back to the MET with an appropriately sized conductor, 30mA RCD protection is provided and my circuits are under max EFLI values then I know my installation is correct. If these 3 points are met then I do not need to worry about supplementary equipotential bonding in the bathroom. You seem to be confused about the actual requirements.... A simplified version of your opening post, would of said “ do you test for extraneous conductive parts that require bonding?”

Exposed pipe work that requires supplementary bonding in a bathroom to me would

Supplymentary bonding is not required for extraneous conductive parts (unless they are within touching distance of exposed conductive parts and the resistance between the two is greater than 1667 ohms) Main equipotential bonding is.

Do you carry out the tests

Supplymentary bonding is not required for extraneous conductive parts (unless they are within touching distance of exposed conductive parts and the resistance between the two is greater than 1667 ohms) Main equipotential bonding is.

My point exactly but how many electricians actually know that? As i believe allot think that having rcd protection alone ommits the need for supplementary bonding.?

 

[Richard Burns]

Many electricians will have automatically ensured that main protective bonding is in place as this is required for all ADS protected circuits, not just bathrooms, and the same applies for all the circuits in the installation that they meet the disconnection times.
These should be in place before you start considering bathrooms, it is at this point that any testing for extraneous conductive parts would have been undertaken.
Then when considering bathrooms 30mA RCD protection is required; ensuring this is also included would then mean that supplementary bonding in the bathroom could be omitted.
Testing for extraneous conductive parts again in the bathroom would not be necessary because it has already been done.
This is not to say that some electricians would assume all main protective bonding is in place and that ADS times are met and so state that 30mA RCD protection is all that is required.

So to answer the question you intended to pose, the testing for extraneous conductive parts would be done earlier and not necessarily in the bathroom as it is the point of entry into the installation of the extraneous conductive part that is the point requiring bonding.
The testing would still be completed, just not in the manner you propose.