Discuss Supplementary bonding in the Electrical Forum area at ElectriciansForums.net

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:   American Electrical Advice Forum

listing a thousand examples of how a conductors insulation might become damaged or how it might come into contact with a Exposed conductive part isn't going to change the definition of a Exposed conductive part unless it's class 2 or plastic etc it's exposed con part by Definition BS7671 Exposed-conductive-parts’ as: Conductive part of equipment which can be touched and which is not normally live,but which can become live under fault

take care bye
 
listing a thousand examples of how a conductors insulation might become damaged or how it might come into contact with a Exposed conductive part isn't going to change the definition of a Exposed conductive part unless it's class 2 or plastic etc it's exposed con part by Definition BS7671 Exposed-conductive-parts’ as: Conductive part of equipment which can be touched and which is not normally live,but which can become live under fault

take care bye
It’s not equipment, it’s support management For cables. Cables which by definition meet the definition of class 2 equipment.
Cables which have an earthed screen like swa.
You can Earth it if you want but it’s not required by bs7671 is all I’m saying.
 
Basically
It's Metal
It's part of the electrical installation
It has the potential to become live under fault - how the fault happened is not relevant here
Yes it should be bonded but that's just my opinion following all sources of official information available to me .

crazy that stuff that didn't need bonding got bonded but real exposed conductive parts didn't.

just read your reply yes it probably would no longer be required to be bonded under most instances I.e RCD protection.
 
Basically
It's Metal
It's part of the electrical installation
It has the potential to become live under fault - how the fault happened is not relevant here
Yes it should be bonded but that's just my opinion following all sources of official information available to me .

crazy that stuff that didn't need bonding got bonded but real exposed conductive parts didn't.

just read your reply yes it would no longer be required to be bonded under most instances I.e RCD protection.
Bonded or earthed? 2 completely different things, certainly it doesn’t need bonding it’s not extraneous.
Did you look at the image I posted from the IET guide earthing and bonding?
Clearly states that it needs neither earthing ( if not a cpc) or bonding (unless extraneous).
Anyway I leave it there.
 
although it could get a bit confusing because it could actually be in contact with the Cable tray and you can visually see - some say cable tray doesn't need bonding but I'm sure I've seen in either Regs or OSG tray is a Exposed conductive part and then... you could meet the requirements where no supplementary bonding is needed anyway, please tell if I'm wrong.

My understanding of the guidance is that:
Tray is not an exposed conductive part if all of the cables on it form a complete wiring system in themselves, that is to say they are insulated and sheathed cables.
Metal trunking is, technically, only an exposed conductive part if it contains single insulated cables, if it was to contain only insulated and sheathed cables it wouldn't be.
 
Bonded or earthed? 2 completely different things, certainly it doesn’t need bonding it’s not extraneous.
Did you look at the image I posted from the IET guide earthing and bonding?
Clearly states that it needs neither earthing ( if not a cpc) or bonding (unless extraneous).
Anyway I leave it there.
Wrong earthing/CPC can form part of an equipotenial zone I.e a bathroom connecting a a class 1 fitting cpc to the supplementary equipotential bonding.

and bonding normally carrys away fault current, always makes me laugh when people try and be clever saying there not the same "They do two different things" not knowing how they work in the first place - Earthing and Creating equipotential are different but bonding is an act of joining two items.
[automerge]1593188058[/automerge]
the only time you could really say there Totally different is if you used Supplementry Equippotential bonding Totally Local I.e not linking it back to the MET/means of earthing its only use then would be keeping Metal parts at the same potential to avoid shock and that alone.
 
Last edited:
Wrong earthing can form part of an equipotenial zone I.e a bathroom connecting a a class 1 fitting cpc to the supplementary equipotential bonding.

and bonding also carrys away fault current, always makes me laugh when people try and be clever saying there not the same "They do two different things" not knowing how they work in the first place - Earthing and Creating equipotential are different but bonding is an act of joining two items.
[automerge]1593188058[/automerge]
the only time you could really say there Totally different is if you used Supplementry Equippotential bonding Totally Local I.e not linking it back to the MET/means of earthing its only use then would be keeping Metal parts at the same potential to avoid shock and that alone.
Not being clever but they are NOT the same thing at all.
Hence they are both sized and installed using completely different regulations for the purpose of completely different tasks, they are interlinked but are not the same
 
yep creating Equipotential and earthing are different.

you said something is only Exposed conductive part if it is used as CPC lol - BS7671 a metal part not forming part of a circuit but part of electrical installation- so requiring a CPC LOL.
 
yep creating Equipotential and earthing are different.

you said something is only Exposed conductive part if it is used as CPC lol - BS7671 a metal part not forming part of a circuit lol.
The function of Protective bonding Is minimising the magnitude of touch voltages within the building/installation when an earth fault occurs between exposed conductive parts and extraneous conductive parts , for pme arrangements it will also be required to carry diverted neutral currents in the event of an open PEN fault.
Now earthing is the connection of all exposed conductive parts of the installation to the main earthing terminal for the purpose of operating the protective devices due to a fault to earth for protection against electric shock.
Seem like completely different things to me?
 
wrong CPC can be Equipotential what do you think happends to that Class 1 light fitting in the bathroom - where do you think that CPC connects? so what other job do you think that bonding is doing? carrying away the fault current and bringing metal part to same potential the same as a earth.
 
wrong CPC can be Equipotential what do you think happends to that Class 1 light fitting in the bathroom - where do you think that CPC connects? so what other job do you think that bonding is doing? carrying away the fault current and bringing metal part to same potential the same as a earth.
Cpc can be equipotential?? What does that even mean? , Jesus Christ it’s not rocket science is it?
This debate has gone a bit south.
 
Equipotential bonding is bringing things to the same potential

earthing carrying away fault and bringing as close to earth potential.

What do you think the CPC in that class 1 light fitting connected to the Equipotential bonding in bathroom and you don't think Bonding also eaths object?

Totally Local Equipotential bonding(not linked to MET) will only bring items to same potential and nothing else.
 
Last edited:
The cpc when connected to supplementary bonding in a bathroom and linked to all circuits/ cpc’s serving the location was to keep the touch voltages below 50v.
the introduction of additional protection by an rcd to all circuits serving the location has now removed the requirements for having to install supplementary equipotential bonding in a bathroom.
Supplementary equipotential bonding is NOT protective bonding , it by its name, supplements fault protection or is an addition to it.
 
Last edited:
yeah the CPC connected to the Equipotential bonding will it not be at the same potential? is it not providing Equipotential? what's another name for CPC - Earth.

Is the Bonding not also earthing when connected to the MET?

Just find it funny.

But good argument take it easy.
 
yeah the CPC connected to the Equipotential bonding will it not be at the same potential? is it not providing Equipotential? what's another name for CPC - Earth.

Is the Bonding not also earthing when connected to the MET?

Just find it funny.

But good argument take it easy.
I’m just trying to explain the difference but you don’t want to listen so it’s a bit frustrating on my part but yeah , take it easy man
 
Final note I didn't read the picture you posted and that is baffling!!! to me it's does say tray doesn't need bonding - considered me Baffled, yet I can probably find as many sources that say it does and as many that say it doesn't. Baffffllled!!!!
 
earthing carrying away fault and bringing as close to earth potential.

Earthing, ensuring that a fault to metal parts is detected by protective devices, ensuring that a large enough fault current flows to ensure timely clearing of the fault to avoid danger and maintaining the touch potential at a low enough level to be relatively safe until the protective device does clear the fault.
[automerge]1593201483[/automerge]
Final note I didn't read the picture you posted and that is baffling!!! to me it's does say tray doesn't need bonding - considered me Baffled, yet I can probably find as many sources that say it does and as many that say it doesn't. Baffffllled!!!!

Tray needs main bonding if it is bringing an extraneous earth potential in to an installation (if it is in contact with the ground, joins two buildings together etc)

Tray needs supplementary bonding if, after all main bonding and earthing has been connected, it has a connection to earth which has a resistance which could lead to a person recieving a fatal shock if they were to touch it during fault conditions.

Tray needs earthing if it is carrying single insulated conductors.
 
Last edited:
Strangely I think most of us were taught at school earthing providing a path of least resistance to Earth and preventing electric shock I.e our body would be the path of least resistance without earthing and most GCSE physics books will cover this but current BS 7671 and electrical installation books skip or only very briefly hint at this focussing on ADS and thats fine but this was obviously a means before any protective device even existed and where the name came from etc it's original purpose and probably shouldn't be skipped.

..
 
Last edited:
Strangely I think most of us were taught at school earthing providing a path of least resistance to Earth and preventing electric shock

I wasn't taught about 'path of least resistance', I was taught the science of electricity, ohms law etc.
Electricity does not 'take the path of least resistance' it splits between all available paths and the current in each path is proportional to the resistance.
 

Reply to Supplementary bonding in the Electrical Forum area at ElectriciansForums.net

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

Electrical Forum

Welcome to the Electrical Forum at ElectriciansForums.net. The friendliest electrical forum online. General electrical questions and answers can be found in the electrical forum.
This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock