Schedules of Inspections. Clarity

[PrenticeBoyofDerry]

That is why I asked the question, trying to understand the relevant regulations regarding supp bond as additional protections, had flummoxed me.
I realy needed some clarity
You have been a great help it is very much appreciated.

 

[ricicle]

I disagree that the 'pigtails' linking the enclosures are supplementary bonding conductors. These will be to maintain earth continuity between exposed conductive parts and are therefore CPCs.

 

[PrenticeBoyofDerry]

So what would be an example of additional protection through the use of supplementary bonding?

 

[dingbat]

So what would be an example of additional protection through the use of supplementary bonding?

See 701.415.2 or 705.415.2.1

But first read 415.2 including the notes.

 

[holmslaw]

..

 

[scottyboyiow]

It might be worth reading Part 2 of BS7671. I wouldn't say the 'pigtails' are cpc's - definition: 'A protective conductor connecting exposed conductive parts of equipment to the MET'. The 'pigtails' do not directly link these parts to the MET. Instead I would say they are a 'Bonding Conductor'?? Supplementary bonding conductors are no longer listed in Part 2. This is because, from my understanding, supplementary bonding now covers bonding conductors, PEB's etc. So in this case bonding conductor would cover the pigtails and therefore be marked under additional protection.

 

[EFLImpudence]

cpc's - definition: 'A protective conductor connecting exposed conductive parts of equipment to the MET'.

That's what they are doing, therefore...

 

[PrenticeBoyofDerry]

I have read the regulations and notes, still as clear as mud!
So you have a metallic trunking, within that runs line(s), neutral and a cpc for that circuit.
The circuit has controls/enclosures that operate and isolate a piece of equipment. They are all also metallic, each metallic enclosure lid has pigtail earth connections to the casing of the enclosures's box.
This has continuity with the trunking back to the MET at the DB, which also connects up main bonding conductors to gas/water/oil supply pipes.
So we have a situation where exposed and extraneous parts are bonded together, is that compliant to supplementary bonding?

 

[dingbat]

So you have a metallic trunking, within that runs line(s), neutral and a cpc for that circuit. The circuit has controls/enclosures that operate and isolate a piece of equipment. They are all also metallic, each metallic enclosure lid has pigtail earth connections to the casing of the enclosures's box.

So, there you have exposed conductive parts. (Read the definitions, including the one for 'electrical equipment'.) You might also want to check out regulations 543.2.1-7.

This has continuity with the trunking back to the MET at the DB, which also connects up main bonding conductors to gas/water/oil supply pipes.
So we have a situation where exposed and extraneous parts are bonded together,...

Yes, we do this all the time. See diagram 2.1 on page 32.

... is that compliant to supplementary bonding?

This question makes no sense - your use of words is unclear - but if you look again at page 32 your answer is right there.

 

[PrenticeBoyofDerry]

is that compliant to supplementary bonding?

This question makes no sense - your use of words is unclear

Maybe compliant was not the correct term to use, but would you tick the box in additional protection regarding supp bonding?
Looking at the diagram, does this mean that supp bonding is only deemed present, when exposed conductive parts are linked via pigtails directly to extraneous conductive parts, thus making the connection between metallic enclosures not valid as far as supp bonding is concerned.
Does that make senses.
At the end of the day, I am try to find out, when would a tick go in the presences of supp bonding under additional protection, I am finding it hard to find an example.

 

[EFLImpudence]

but would you tick the box in additional protection regarding supp bonding?

Only if supplementary bonding is applied where it should be. We have decided that if SB is not required (because of RCD) then N/A.

Looking at the diagram, does this mean that supp bonding is only deemed present, when exposed conductive parts are linked via pigtails directly to extraneous conductive parts,

No. If SB is required then extraneous conductive parts are just linked together or linked and connected to a CPC somewhere. It is not 'deemed' to be SB orpresent - it either will be SB and present or not.
Exposed conductive parts will already be earthed.

thus making the connection between metallic enclosures not valid as far as supp bonding is concerned.

Not sure what that means.

Does that sense

Not really

At the end of the day, I am try to find out, when would a tick go in the presences of supp bonding under additional protection

See above

Look at it this way.
The green and yellow wires all look the same.

Some are there in case of a fault (of negligible impedance, as they say) to operate the CPD. These are earths connected to the metal (exposed conductive parts) of an appliance.

Others are to ensure pipes and other metal parts which are not part of the electrical system (extraneous conductive parts) are at the same potential - especially in bathrooms before RCDs - but not all metal parts are extraneous conductive parts.

You have to decide if a part is extraneous and then if it need supp.bonding. If it does then fit it and tick the box. If it doesn't then N/A.

Have I got that right?

 

[dingbat]

...would you tick the box in additional protection regarding supp bonding?

No. Because what you describe is all to do with earthing.

Looking at the diagram, does this mean that supp bonding is only deemed present, when exposed conductive parts are linked via pigtails directly to extraneous conductive parts, thus making the connection between metallic enclosures not valid as far as supp bonding is concerned.
Does that make senses.

No. That doesn't really make sense. You have to get rid of your unclear thinking then replace it with the right stuff. Earthing and bonding are two different things.

At the end of the day, I am try to find out, when would a tick go in the presences of supp bonding under additional protection,

When, for additional protection, you have decided that you want/need to supplement your main bonding with - here it comes - supplementary bonding.

I am finding it hard to find an example.

Try bathrooms, again.