Earthing vs. Bonding: What's the Difference?

Electricians often get confused between earthing and bonding of an electrical installation. James Curnow explains the differences and the key references within the UK wiring regulations BS7671.

What is the difference between exposed conductive parts and extraneous conductive parts. What is equipotential bonding?

🕐 TIME STAMPS 🕕
======================
00:00 What is bonding what is earthing
00:16 What does BS7671 say
01:02 Exposed conductive parts
01:23 Fault conditions
01:46 Bonding
02:37 Extraneous conductive parts
02:54 TN supply
03:13 Same potential
03:49 Pipework passing through a building
04:57 Supplementary bonding
05:31 Omitted supplementary bonding
06:01 Supplementary bonding is required

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#efixx #earthing #bs7671

[quinsboy]

Many thanks for this, I like the delivery style which is easy on the ear, technically correct and very userul.

[sergiofernandez]

Earthing vs. Bonding. I spoke to Pete the Plasterer and he gave me a different answer.

[gbelectricks]

Welcome to efixx James, looking forward to more content👊

[davehunt]

A lot of info delivered, well done and thank you

[UsualYaddaYadda]

Thank goodness that the tongue twister BS7671 is written in the description text... it's impossible to ascertain from any of the occasions that it is spoken... "be'esevixevven-one" good, clear, informative video aside from that. Thanks.

[davidblyth]

An interesting talk on the subject.
My professional work is on weapons systems which included electronics.
Earthing is significantly more complex due to the high frequencies and the risk of potential differences over conductors at distances over a portion of a wavelength of the frequencies used in the system. This could induce noise which affects the correct function of the circuitry, particularly digital circuits. So there may be an earth and several common bonding points to address this.
We specify bonding quality as resistance/conductivity eg mOhms.
I have seen poor bonding in a power circuit produce heat till the connection was damaged by heat and then arcing. This is of particular importance where the system is aboard a moving platform eg aircraft, ship of land vehicle.

[Dog-whisperer]

Welcome to eFIXX James
Nice explanation on earth bonding. Well done 👍

[Sam-cllg]

How do we get 100 and 48 volts at 3:14?

[grahamheath]

This topic always makes we wonder why we don’t just have an earth rod at every house as effectively (at least in my view) extraneous conductive parts perform broadly the same function and surely there would be a lot of advantages to doing this, and I would have thought it would prevent PEN faults.

[yasuke]

What is meant by potential?

I'm not understanding the concept.

I understand that extraneous conductive parts can be dangerous unless earthed, but when they become the same equal potential, what does that mean?

Does it just mean they have the same eletrical charge or something?

[Jack-zrlm]

Great video, Could you do a video explaining about the neutral conductor?

[Pgan]

Thank you for a great video. Q1) Would Bonding Works if the separate parts are connected to separate earthing rods, in cases where large distance makes running a cable back to the other parts costly or impractical, compared to running a cable to a new separate Earth Rods. Since earth potential is zero, there will be no cable link between Earth Road 1 to 2 to 3.. etc 2) It would be clearier if more pictures examples be shown for Bonding cases

[ld-dmaker]

im always confused because where i live, ground isn't provided to you, you have to put in a grounding rod and your neutral never connects to "your" ground (they're grounded only at the transformer). so we only have "one ground" that connects *every* device, pipe and outlet in the house to the grounding rod so that in the case of a fault, it all dumps there, no need for equipotential bonding as all "ground" in outlets or pipes are at 0v respective to the earth

[xBULLETfromABOVEx]

Recap
Earthing - for Exposed conductive parts that are part of the installation (metal switches)
Equipotential bonding - for extraneous conductive parts that are not part of the installation but could become live under fault conditions (gas pipes)

[jayantvm]

Why earth provided a return path to electric current ?

[Dog-whisperer]

Wow Joe Robinson has been pushed aside. Will regulation corner continue with Joe ?

[mikeeb]

I think it was a good effort, but the clear difference has not been established to me. I understand "extraneous" aspects of the installation but the example above (especially the flat with the water main line) did not help- the excessive use of the word and not a more drawn out explanation if why that was considered part of the installation when you stated the ground on the 1st part of the flat was not considered part of the installation could have provided a better explanation. After all, by adding a ground you are making it part of the installation. Perhaps maybe explaining a clearcut definition of an installation would have been better first. Again, it was a nice shot but it was missed ( at least to me).

[olivertaylor]

If something is metal just make sure it's connected to the earth 🌎 with a green and yellow wire.

[oal]

Pre watching: earthing: wire goes all the way back to earth block, bonding : the connection can be lost if x item bonded to it gets removed= losing its earth.

[Tryingtimes]

Hi James welcome to the “dark side” of electrics.