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.
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.
The correct way to deal with a PEN fault is to use a PEN fault detection device. Not install a second earthing method. And TT doesn't make a good earth. The resistance is greatly variable and higher than other methods.
@@efixx no one I mean no one can or could ever replace Joe on regulation corner. There’s only room for one regulation Boffin at regulation corner. And that’s Joe Robinson.
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
That’s a TT system, the fault isn’t dumped into the ground the ground is used as the fault path back to the star point of the transformer, the problem with a TT system is getting a low enough resistance back to the transformer, that’s why you then need RCDs
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.
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?
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).
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)
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
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.
It's the potential difference between different parts of the ground. It looks like they're trying to show the potential difference from the supply substation, etc. to the point the person is standing and from where the person is standing to both the point of supply (Meter, etc.) and to the extraneous metal coming out of the ground that has been bonded (they are standing in the middle as far as the potential difference shows). I'm not sure on this but I would suspect they've chosen 48V as the standard ELV safe-touch limit is
@Timothy Dixon wth are you talking about of course they have nuetrals in their residence you need to not for everything here in the us we can often use split phase for 240 instilations 120 volt phase to ground/neutral and 240 phase to phase or should it be leg to leg sense it's all one phase just with the nuetral tapped in the middle of the Transformer. But ya you need a nuetral for most cases because of unbalanced loads.
My neighbour is a poor pensioner skint her light in the bathroom was dead.so as a favour I fitted a new one there were 5 wires into the light straight away I told her she needs the wall fan rewired as there was no isolation switch and they were using the c.p.c. as a switched live and the outside light had no cpc on it.I put it all back together as it was the only way to get out the house she promised she would get it fixed proper,it had been like that for 10 years I checked the fan case for live it wasn’t.What do you do leave her in the dark I tried disconnect the fan and light No No it’s been working for 10 years it’s OK haha. It was a builder that fitted it in the first place I just did like for like.
Earthing vs. Bonding. I spoke to Pete the Plasterer and he gave me a different answer.
I spoke to a kinky gardener. He also gave me a different answer!
If something is metal just make sure it's connected to the earth 🌎 with a green and yellow wire.
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.
Many thanks for this, I like the delivery style which is easy on the ear, technically correct and very userul.
Thanks for the feedback. 😊
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.
I have always wondered this myself, why doesn't every property have a TT rod just incase.
The correct way to deal with a PEN fault is to use a PEN fault detection device. Not install a second earthing method.
And TT doesn't make a good earth. The resistance is greatly variable and higher than other methods.
So now you’re suggesting that you megger every wire lol
A lot of info delivered, well done and thank you
Glad it was helpful!
Wow Joe Robinson has been pushed aside. Will regulation corner continue with Joe ?
😂 Fair point, maybe I should hand it over, tune in tomorrow to find out...
@@efixx don’t you dare
@@efixx no one I mean no one can or could ever replace Joe on regulation corner. There’s only room for one regulation Boffin at regulation corner. And that’s Joe Robinson.
Fantastic content James 🦾
Cheers Gaz. 😊
Welcome to eFIXX James
Nice explanation on earth bonding. Well done 👍
Thanks Sean. 👍
Welcome to efixx James, looking forward to more content👊
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
That’s a TT system, the fault isn’t dumped into the ground the ground is used as the fault path back to the star point of the transformer, the problem with a TT system is getting a low enough resistance back to the transformer, that’s why you then need RCDs
Worse explanation design to confuse students
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.
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?
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).
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)
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
I would like Joe Robinson back. Sorry I hardly understand James.
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.
How do we get 100 and 48 volts at 3:14?
I would say it's probably an estimate and quite a good one I think.
It's explained in detail in this video.
th-cam.com/video/qXgfGUymomU/w-d-xo.html
It's the potential difference between different parts of the ground.
It looks like they're trying to show the potential difference from the supply substation, etc. to the point the person is standing and from where the person is standing to both the point of supply (Meter, etc.) and to the extraneous metal coming out of the ground that has been bonded (they are standing in the middle as far as the potential difference shows).
I'm not sure on this but I would suspect they've chosen 48V as the standard ELV safe-touch limit is
At equal voltage etc but I wouldn't like to test it.
Why earth provided a return path to electric current ?
So it's the same. It's all connected to earth.
Hi James welcome to the “dark side” of electrics.
He'll help shine a light into it. 😂
😆
Great video, Could you do a video explaining about the neutral conductor?
They don’t have a neutral incoming on their residence’s they use it on 3 phase systems
@Timothy Dixon wth are you talking about of course they have nuetrals in their residence you need to not for everything here in the us we can often use split phase for 240 instilations 120 volt phase to ground/neutral and 240 phase to phase or should it be leg to leg sense it's all one phase just with the nuetral tapped in the middle of the Transformer. But ya you need a nuetral for most cases because of unbalanced loads.
Very informative, thanks.
My neighbour is a poor pensioner skint her light in the bathroom was dead.so as a favour I fitted a new one there were 5 wires into the light straight away I told her she needs the wall fan rewired as there was no isolation switch and they were using the c.p.c. as a switched live and the outside light had no cpc on it.I put it all back together as it was the only way to get out the house she promised she would get it fixed proper,it had been like that for 10 years I checked the fan case for live it wasn’t.What do you do leave her in the dark I tried disconnect the fan and light No No it’s been working for 10 years it’s OK haha. It was a builder that fitted it in the first place I just did like for like.