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Do you any solution to my problem. In my place there is frequent high voltage (240v+). Is there anything i can do to maintain the 220V? We are using 220v in my place.
Wow so true. I wanted to like him, because he attempts to explain the NEC, but he just goes on and on without clear explanations and loves to hear himself talk.
Electrical engineer here, I worked with electrical engineer colleagues who had way more experience than me and they actually thought the ground rod is for ground faults, I argued with them about this and they wouldn't even believe me and thought I was crazy lol. FYI, electricity takes ALL paths, not just the least resistance. What I mean about ALL paths is all parallel paths, however the path of least resistance is where most of the current will go to. Grounding and bonding are totally different things
I work in the super computer industry as a Mechanical Engineer, and having to explain differences in Neutral, Ground, and Bonding to other engineers is something that happens often.
Same here. In my university, many people including some of the professors thought that a ground fault could be "magically fixed" just by using a ground rod alone. When i told them that a ground should be connected together with neutral at the main panel in order to trip the MCB, they confidently told me i was wrong and i believe that they must think that i was stupid.
@@ashchbkv6965 Grounding and bonding is not taught in schools let alone MEP engineering. MEP engineering is something you can only learn by actually going into the industry and be trained by a mentor and doing your own research. Theory and knowledge from school helps and will accelerate your learning.
For the minds like mine that aren’t scientific, concepts like this are extremely complicated. Huge shout out of appreciation to those of you who are STEM.
I was working as an apprentice for a retired electrician that ran a power plant so he knew his craft well when a friend from the local electric company called because they couldn't figure out why people were getting shocked climbing out of the swimming pools on that particular street. These were newly built beach houses that all had swimming pools and all met code with every stage inspected by another retired electrician that knew his craft. The problem was all these houses had two 200 amp panels with constant high loads during the day and the street was fed from one phase. I can't explain the hows and whys as I'm not a licensed electrician but when the power company ran another phase and kept the loads as balanced as they could the problem went away. Apologies for the book.
Cool explanation. I was a Contractor for AT&T back in 2010, and in Florida I went throughout the State and upgraded their ground wires replacing the smaller copper ground wires with 6 foot copper rods. This was around the time they were upgrading to Fiber Services.
Electricity will dump most of the current on the path of least resistance. It will still trickle some of the current on the path of high resistance. It's like a voltage divider. Electricity will go wherever it can. It just will put different amounts of current on each path depending on the path's resistance.
That's only of the path of least resistance cannot carry the total voltage produced. Imagine a very narrow water pipe that branches off from a very wide diameter pipe. If the water flowing through the pipe does not exceed its maximum capacity then no significant amount of the water is going to travel by way of the smaller branch
@@reshpeck Wrong, and dangerously so. Current will flow through every branch in a parallel circuit in inverse proportion to the resistance along that branch, because the voltage at the head of each branch is the same. There's no such thing as a conductor that can't carry a certain voltage -- either its power rating is sufficient to carry the current going through it, or it fails and creates an open circuit.
@@reshpeck That's not correct. If you have two ground paths, 1 is 1 Ohm and the other is 50,000 Ohm. The 50,000 will still see some current, just extremely small amounts...as stated above, it's a current divider. Also stating that something cannot carry the total voltage makes no sense. I regularly put 1,000,000+ V on 14 gauge wire.
Paul: As usual clear concise information. You have taught me very much over the three (3) years, INCLUDING this information in previous lessons. Once again, Thank you.
Glad to see such a clear explanation about how fault current isn't significantly handled by ground rods. Too many people misunderstand this. I remember a forum post about a guy installing a hot tub using two conductor ungrounded cable and just driving a local ground rod at the tub... He could use a pointer to this video.
I second the motion! Nice job on explaining the practical application of a ground rod. True that so many uneducated individuals falsely think it provides and kind of protection against ground faults.Neutral bonding so that electrical currents can get back to the source is the proper means of clearing a fault by allowing the short to trip a breaker.
This diagram depicts a TNCS system (Terra Neutral Combined Separate Supply), and the main reason for the ground rod, is to prevent injury when there's a loss of neutral between the meter and supply transformer.
I've seen all your videos and all of them are so educational..make a video about grounding a house or a building ...the difference on grounding systems etc..great great job for those videos man. 🔌🔌
I love these videos, and especially the illustrations. However, I find the illustration of alternating current to be highly distracting, like flashing neon lights. A better approach would be to slow the motion down a bit, and trace the current flow incrementally through the circuit. Perhaps stop-motion occasionally could be used to give the viewer a chance to absorb all the visual and verbal inputs. There's just too much going on simultaneously. In addition, I would suggest that the point at which the ground fault is occurring be emphasized by enlarging that area, or highlighting it, or having an arrow point to it, so that it remains a fixed visual reference against which the various current flows can more easily be observed.
You can always pause the video. Or rewind, or even play it at half speed, or slower. People will watch it twice if they are interested and want to learn more, as the further you come along, the more the information you've just been exposed to makes sense. Just rewatch it.
EE here. The main purpose of the grounding rod if to keep the neutral as close to 0 volts as possible in reference to earth. What you say on here is true, but that's not its primary purpose
Is it to keep the neutral at 0 volts, or is it the make the "ground" in the area of utilization the same potential as the neutral conductor? The neutral is a low resistance conductor, whereas the ground is high resistance. Thinking back to my electrical apprenticeship when high voltage installations were being discussed, regarding step potential where you could have a large voltage between footsteps due to earth resistance.
@@abpsd73 that's basically what he said. It keeps the Neutral Referenced to the earth, keeping a 0v potential between the Neutral, Ground, the earth, water pipes, etc. If you don't reference the Neutral of a transformer to earth, you will still get 110/220v etc out of it, but any leg could end up being at earth potential, or it could be somewhere in between. I have worked on systems where they forgot to Bond the Transformer neutral, and every night when a shorted out photocell controlled light switched on, Neutral would become 120v to ground, and the hot would be 0v to ground, because the lamp was doing the Bonding... That was a fun one to diagnose! Lol
@@ke6gwf I ran into one of those situations as well. It was a golf course under construction, and there was 120V on the neutral, so the utility company refused to install a remote metering transponder. I started poking around and noticed the 600-120/208 transformer didn't have a bonded neutral. Shut it down, installed the bond, then powered it back up. A breaker for an underground feeder to a remote panel tripped on power up. The cable got mashed somewhere by a piece of equipment. The crew chief was pretty miffed that a panel was out of commission, and didn't handle the explanation very well that the original installing electrician missed something. If the neutral was bonded from the start, the breaker would have tripped when the cable was hit.
@@abpsd73 good detective work! Lol My story was an industrial machine room that was fed with 3 phase and then had a floor transformer to provide the 110/220v panel supply, and I discovered it by melting the tip off a screwdriver that bridged a ground strip to a cabinet case one evening, but then when I tried to test it and figure out why the next day, everything appeared normal! It took me a few days until I was in the room at dusk and heard the lighting contactor clunk that I made the connection and then discovered that I could make it flip when I turned the correct breaker off and on. The site rep didn't believe me, didn't think it was possible, so I shut a breaker off, and clipped a jumper wire from the hot terminal directly to the ground buss, and said "watch this!" and flipped the breaker on while he screamed at me to stop! Then after nothing happened, I used the tester to show him how the voltage was flipping, and he finally agreed to get the regular electrician to come in, and I guess he was embarrassed when he was told he hadn't bonded the transformer lol (I was dealing with the industrial automation systems.)
While a lightening strike is absolutely made much more manageable and safer by ground rods ,there is another vital function of ground rods taking place continuously and is arguably equally as important. Grounding maintains an equipotential between structures and power lines as a counter to induced voltage from power lines AND from neutral/center tap drift created by unbalanced loads. This second function of a good inter-system ground is worth explaining too. That was an excellent explanation. I might also add that in tight rural and city areas the multiple paths to ground can be of such low impedance (metal sewer and water systems and several other possibilities) that the returning neutral current will split and be shared between the neutral service conductor and the building/neighborhood total ground paths. I have measured it and it is actually very common for a significant amount of Return/Neutral Current to use an excellent groundpath back to the Utility Source.
What about using a ground rod to take away high frequency noise. For example using one to protect the driving electronics of a CNC plasma table from the HF of the plasma torch?
There are much higher requirements for resistance of such grounding device though, you have to test it to make sure there will be enough current to trip the breaker as well as to not create voltage divider with middle point higher than some specific value.
Good point. I had thought these systems were largely used in remote locations because of higher cost for wire. However I since learned that with RCD/GFCI protection, TT grounding is safe and also less prone to EM interference from other devices on the line. I'm told that TT grounding is common in Japan.
@@Mr.Leeroy Yes that is correct I was just keeping simple, In a past life I used to do ECIRs and occasionally had TT installations in rural areas and would pray for acceptable results😂
This is true for the grounding system pictured (TNCS?), but I think for a TT earthed system it IS the fault path. Restiance is still high which is why residual current/ground fault circuit breakers are needed.
saw an air conditioner flow 8 amps through earth @ 180v (from the 230v supply), that's around 6 ohms impedance (TT). The neutral fuse had blown and the wires had melted, shorting the earth cable to the neutral. The compressor started failing but god knows for how long it ran like that
Having just re-installed a new meter base and added a exterior 200 amp breaker panel to meet current NEC code due to a faulty meter that seemed hell bent on setting the side of my house on fire, they will make you install (2) 5/8 x 8ft ground electrodes at least 6 ft apart and the #4 ground wire is to be installed in one continuous run into the main service panel for low impedance purposes. Don't forget your antioxidant paste for the 4/0 & 2/0 aluminum cables 😉 My house was built from scratch during the late 70's so things have changed a bit code wise since then like separating the neutrals and grounds on their own bus bars. Honestly, I don't really see the point of that since the neutral and grounding (safety neutral) wires are linked to the center-tap of the transformer. It looks a little neater, that's all I can say. I was on generator power for 11 days waiting for the parts to arrive for the install. Wasn't going to let some local electrician price gouge me for $500 - $1,000 to install something that took less than a day. Passed my electrical inspection with ease which cost me $125 which wasn't to bad considering. I also now have a spare meter box and breaker panel in my shop just in case something like this ever happens again so I'm able to strip the guts out of the old box and make the repair in less than an hour 😊 As for the grounding rods, most people don't know that for the most part they are really for lightning and static build-up. Now the exception to this is a fence charger which electrifies fence and when touched finds it's way back to the charger via a grounding rod. The more grounding electrodes you install the more powerful a shock they can deliver which is what keeps livestock from escaping 😜
Your have left something very important in your explanation..for all this to work , that ground rod have to be tested. Some guys would think that install a 10’ ground rod is the solution. The fact is that sometimes you need to go 80’ in the ground before your impedance go down to 20 ohms.. is you don’t test the grounding electrode, make sure you have a good insurance.
Great simple explanation to wake people up to the fact that "electricity goes ground" is false and incorrect. I encourage everyone to look at Mike Holt's videos to get an in-depth knowledge of grounding. In essence the "ground wire" is there to clear a fault in an over current condition which sets the circuit breaker. The ground rod (or metal water pipe) it self is there to dissipate a high frequency, high energy DC pulse to the earth which is induced on all metallic parts in a building when lightning strike occurs near by.
Ground wire is to protect to from metal boxes, enclosures, cases, etc from being energized and ready to shock/kill someone. The ground wire is for protection of people. GFCI does a similar thing but measures the current path and trips at very low current going through ground or a person.
@@shockcoach one time we had a big bunch of them stolen from our yard by some copper hounds but they were only 8 ft. long copper clad rods. they took about 100. friggin clowns.
Saying "electricity always wants to return to its source" and that "the source of lightning is essentially the Earth" is not only confusing but not totally accurate.
Correct. I don’t think that’s the reason. It’s because the lightning deposits charged particles on the bare (not insulated) wires of the distribution line when the lightning strikes them. Like charges repel. Also, the Earth is neutrally charged, as in having zero net charge, meaning it doesn't attract nor repel charges on its own. Therefore, the additional charges in the wires repel each other. But since there is a path for the Earth ground through the ground rod, the excess charges can and thus will flow through that path.
So a friend of mine wanted to put lights in some of the palm trees around his property 3 acres ran wiring to the trees so we could use the maximum amount of wire with the least amount purchase twisted all three wires in the Romax together. Then ran a neutral from the light down the palm tree and into the ground with a 6 foot piece of rebar. This worked very well for 30 years with no adverse effects.
It would certainly work, not sure if electrical meters are done differently elsewhere but without a neutral back to the meter I think your friend wouldn't be paying for the juice to power those lights?
Electricity DOES NOT take the "preferred path" to source, it takes ALL PATHS back to source. This hundred + year old misunderstanding was finally corrected 20 some odd years ago and still many teach it incorrectly.
Howdy. Nice explanation. However. Less is discussed about the purpose of the soil rod. The main purpose is to provide a reference null potential. This null potential is then distributed to plumbing, appliances, concrete rebars and so on via the ground wiring (green). Potential equalizing of touchable parts. Observe that the reference null is not soil null during a ground fault in an appliance. The soil impedance will cause the reference null to rise above the global soil null. But the environment of utilization potential will rise alongside the reference null through bonding. The fault touch voltage between the faulting aplliance and the concrete floor will be smaller. So. The rod reference null is not heavily bonded to the global soil null. The best way to provide reference null is not to use just one rod. Use several rods around the house. This will encircle the environment of utilization for best fault potential equalizaton. Better still. Bury a copper wire around the house and connect both ends to the service panel bonding. Regards.
I was pondering over that point as well. Doesn't seem correct, since lightning can also occur between clouds having a difference of electrical potential.
Never explained better. However this explains also why the European system is safer in case a hot wire connect to the ground, they have a "life switch" set to 30mA that would trigger the breaker and interrupt the power from the source 👍🏻
Can you do a video on why "electricity always tries to return to it's source" My understanding is that "electrical current will flow from a point of higher electrical potential to a point of lower potential" but I constantly see this trumped by the first rule and would love to know how it works. Thanks.
there are two types of electrical charge to be considered: in static electricity, you have a "positive" or "negative" charge stored, which seeks to discharge to a point of opposite polarity. this includes lightning and capacitors. in electrical systems that you get work out of, you have an electrical source, whether a battery or a generator. in either case, it has to be a complete circuit to be usable - which means electricity must flow out from the source, through the load, and back to the source; much like a bicycle chain. it has to be a complete loop to propel the bicycle.
The 'source' rule never need 'trump' the potential rule. Potential is relative. A source internally generates a difference of potential--by definition If current did not return to the source (in time) then that implies a charge is building up elsewhere (which can happen), but this then implies that there is a new differential elsewhere that 'wants' to equalize, and it wants to do so with the source. Consider that charge, in the context of power circuits, needs to be constantly replenished--be it by a spinning turbine, a chemical reaction, or photons (photoelectric effect). Where is the charge going to be replenished from? Can it be stolen from some bank? Well if it steels charge, that 'charge hole' will want to be filled. Consider that happening on a contiguous basis and you have a continuous circuit with charge 'returning to source.'
Thanks for the info.. now i know why everytime that a lightening is happening here in the farm.. the wire that connected to the ground rod is a having a sparks...
if the grounded conductor between the panel and the transformer fails, the hope is that the grounding electrode will carry enough current to keep the resulting voltage imbalance from being disastrous. it is also used to provide a reference for "zero" volts to ground in the grounded portion of the electrical system. lightning arrester electrode systems are completely SEPARATE from the grounding electrode system. this is also different from an equipotential bonding system which is there to make sure all non current carrying conductive material is at "ground" potential.
i was trying to find a polite way of disagreeing with Paul(makers of vid) but you beat me to it. my experience of 45 years teaching upcoming electricians in the field i try to make sure they know the important things that will save lives. one of which is that ground rod (which new NEC code says 2 grounds rods have to be installed) as Ken said is not intended for lightning although it could dissipate some minor strikes, its purpose is to keep a reference to ground. if you lose your neutral an imbalance of voltage can occur(voltage goes down ,current goes up, fries stuff. also i tell them be very carful when disconnecting a ground rod,if it does have a neutral problem could get a big spark when disconnecting.Pauls still a smart guy
Always clear knowledge and interestingly ground rods just can't be placed anywhere and using more than one changes the resistance but some people already knew that
Questions: my system is DIY. Where are you attaching the ground wire and rod to? My area suffers a lot of lightning. A strike a couple of years ago flipped the circuit breaker, but to no avail, and damaged more things than I could afford to replace. These rods are rare in Australia.
If the neutral and grounding bar is connected are connected to ground then how does landing a hot wire on the ground rod have only the path of high resistance through the ground rods and not through the grounding conductor through the transformer
I think people are missing the fact that current will flow to the ground rod, not earth. Earth might have high impedance but the lightning rod is providing safe path for ground faults as it is a good conductor.
Why is the black hot leg wire at the lamp socket not connected / landed on the socket base terminal as is now shown in the video? Why is the socket's base ground wire shown in yellow instead of green per USA NEC Code?
Actually I would add something to the video was missed which during lightning there is something add to protect against like lightning protection and surge protection. The part will allow the high current to go to the ground during the fault of lightning on the load or transformer sides called surge protection which allow that high current to discharge in the ground. And during the ground fault I would add also something I believe what mean in the video is a high resistance grounding system which most of the time the user install to provide a continuous operation during faults (for some costumer operation needs).
here in Denmark most households use TT system, however places like in the city, were its not possible to burry a rod in the ground due to asphalt they use TN system which is just the transformer stations ground rod ( N ) as i understand
You see in Australia, fault current WILL flow to earth rod. That's because in the main switchboard, Neutral is tied to Earth rod. That link is called multiplied earth neutral (MEN). If neutral in the mains develops high resistance, or is cut, all current goes from phase to earth rod and back to transformer. Very dangerous situation, since all appliances that are earth will have high potential on them.
Electrical engineer here, the ground is negatively charged and the atmosphere is positive, meaning there's a surplus of electricity in the air as opposed to the ground and it needs somewhere to go other than elsewhere in the atmosphere. That's why the grounding wire is always black aka ground not hot though technically all wires are to be assessed as hot. So when you have a lightning strike you want that electricity to have the path of least resistance where it can be disapated back to the earth.
In some soil conditions multiple grounding rods, or complex grounding networks, may be required, in super dry soil, shallow bedrock etc. There are specs for how good the connection is between the earth and the ground rod, and if it doesn't pass something more will have to be done.
So, if under normal circumstances,, the main service neutral came loose and fell off of it's lug....would the return current just travel down the ground rod, through the ground and up the ground rod connected to the transformer and everything would continue working? I guess not because ohms law means the high resistance of the ground would mean low amps and things would crazy dim...so we would know the main neutral wire fell off the lug. Do I have this correct?
Would you be able to do a short video explaining what difference is between Volt Free Contact and Dry Contact? A lot of people seem to confuse these two. Thanks
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Do you any solution to my problem. In my place there is frequent high voltage (240v+). Is there anything i can do to maintain the 220V? We are using 220v in my place.
What are the effects when no grounding used (both system and protection grounding))?
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In 2 minutes, you just explained what would take Mike Holt 3 HOURS - and I understood you better. Nice work!
You are wrong sir
Yeah that talks about his boat n skies then more bla bla
This guy wasn't busy thanking Jesus and having a prayer circle before explaining
Soooo true lol 🤣...love mike holt though!
Wow so true. I wanted to like him, because he attempts to explain the NEC, but he just goes on and on without clear explanations and loves to hear himself talk.
Electrical engineer here, I worked with electrical engineer colleagues who had way more experience than me and they actually thought the ground rod is for ground faults, I argued with them about this and they wouldn't even believe me and thought I was crazy lol. FYI, electricity takes ALL paths, not just the least resistance. What I mean about ALL paths is all parallel paths, however the path of least resistance is where most of the current will go to. Grounding and bonding are totally different things
I am not an electrical engineer, but what you are saying sounds logical to me.
I work in the super computer industry as a Mechanical Engineer, and having to explain differences in Neutral, Ground, and Bonding to other engineers is something that happens often.
And our lives depend on your engineer colleagues. What's wrong with the education system?
Same here. In my university, many people including some of the professors thought that a ground fault could be "magically fixed" just by using a ground rod alone. When i told them that a ground should be connected together with neutral at the main panel in order to trip the MCB, they confidently told me i was wrong and i believe that they must think that i was stupid.
@@ashchbkv6965 Grounding and bonding is not taught in schools let alone MEP engineering. MEP engineering is something you can only learn by actually going into the industry and be trained by a mentor and doing your own research. Theory and knowledge from school helps and will accelerate your learning.
For the minds like mine that aren’t scientific, concepts like this are extremely complicated. Huge shout out of appreciation to those of you who are STEM.
I was working as an apprentice for a retired electrician that ran a power plant so he knew his craft well when a friend from the local electric company called because they couldn't figure out why people were getting shocked climbing out of the swimming pools on that particular street. These were newly built beach houses that all had swimming pools and all met code with every stage inspected by another retired electrician that knew his craft. The problem was all these houses had two 200 amp panels with constant high loads during the day and the street was fed from one phase. I can't explain the hows and whys as I'm not a licensed electrician but when the power company ran another phase and kept the loads as balanced as they could the problem went away. Apologies for the book.
Cool explanation. I was a Contractor for AT&T back in 2010, and in Florida I went throughout the State and upgraded their ground wires replacing the smaller copper ground wires with 6 foot copper rods. This was around the time they were upgrading to Fiber Services.
Electricity will dump most of the current on the path of least resistance. It will still trickle some of the current on the path of high resistance. It's like a voltage divider. Electricity will go wherever it can. It just will put different amounts of current on each path depending on the path's resistance.
That's only of the path of least resistance cannot carry the total voltage produced. Imagine a very narrow water pipe that branches off from a very wide diameter pipe. If the water flowing through the pipe does not exceed its maximum capacity then no significant amount of the water is going to travel by way of the smaller branch
@@reshpeck Wrong, and dangerously so. Current will flow through every branch in a parallel circuit in inverse proportion to the resistance along that branch, because the voltage at the head of each branch is the same. There's no such thing as a conductor that can't carry a certain voltage -- either its power rating is sufficient to carry the current going through it, or it fails and creates an open circuit.
@@reshpeck That's not correct. If you have two ground paths, 1 is 1 Ohm and the other is 50,000 Ohm. The 50,000 will still see some current, just extremely small amounts...as stated above, it's a current divider. Also stating that something cannot carry the total voltage makes no sense. I regularly put 1,000,000+ V on 14 gauge wire.
@@mikemazzantini6397 makes sense. I have dealt with leaking voltage on a spark plug wire but the cylinder still got its voltage for spark.
It is a current divider.
I think it's important to explain the differences between a TN, TT and IT grounding system in a video like this
Paul: As usual clear concise information. You have taught me very much over the three (3) years, INCLUDING this information in previous lessons. Once again, Thank you.
Glad to see such a clear explanation about how fault current isn't significantly handled by ground rods. Too many people misunderstand this. I remember a forum post about a guy installing a hot tub using two conductor ungrounded cable and just driving a local ground rod at the tub... He could use a pointer to this video.
People still do that for cooking range. Two 40a wires only with one cooper wire go to ground.
you are the best channel for electrical power system graduates
I second the motion! Nice job on explaining the practical application of a ground rod. True that so many uneducated individuals falsely think it provides and kind of protection against ground faults.Neutral bonding so that electrical currents can get back to the source is the proper means of clearing a fault by allowing the short to trip a breaker.
Brief and perfectly explained like always.
This diagram depicts a TNCS system (Terra Neutral Combined Separate Supply), and the main reason for the ground rod, is to prevent injury when there's a loss of neutral between the meter and supply transformer.
I think your comment should be on the top, since this is point I was missing
This always confused me, this was genuinely useful!
I've seen all your videos and all of them are so educational..make a video about grounding a house or a building ...the difference on grounding systems etc..great great job for those videos man. 🔌🔌
This channel is brilliant ! thank you for your hard work and help, I am currently binging them all
I love these videos, and especially the illustrations. However, I find the illustration of alternating current to be highly distracting, like flashing neon lights. A better approach would be to slow the motion down a bit, and trace the current flow incrementally through the circuit. Perhaps stop-motion occasionally could be used to give the viewer a chance to absorb all the visual and verbal inputs. There's just too much going on simultaneously. In addition, I would suggest that the point at which the ground fault is occurring be emphasized by enlarging that area, or highlighting it, or having an arrow point to it, so that it remains a fixed visual reference against which the various current flows can more easily be observed.
You can always pause the video. Or rewind, or even play it at half speed, or slower. People will watch it twice if they are interested and want to learn more, as the further you come along, the more the information you've just been exposed to makes sense. Just rewatch it.
AC doesn't flow just forward in a linear fashion. It alternates back and forth in a wire.
Jesus Christ shut up.
The idea of highlighting the "head" of the "flashing current snake" is a great idea.
EE here. The main purpose of the grounding rod if to keep the neutral as close to 0 volts as possible in reference to earth. What you say on here is true, but that's not its primary purpose
Is it to keep the neutral at 0 volts, or is it the make the "ground" in the area of utilization the same potential as the neutral conductor? The neutral is a low resistance conductor, whereas the ground is high resistance. Thinking back to my electrical apprenticeship when high voltage installations were being discussed, regarding step potential where you could have a large voltage between footsteps due to earth resistance.
@@abpsd73 that's basically what he said.
It keeps the Neutral Referenced to the earth, keeping a 0v potential between the Neutral, Ground, the earth, water pipes, etc.
If you don't reference the Neutral of a transformer to earth, you will still get 110/220v etc out of it, but any leg could end up being at earth potential, or it could be somewhere in between.
I have worked on systems where they forgot to Bond the Transformer neutral, and every night when a shorted out photocell controlled light switched on, Neutral would become 120v to ground, and the hot would be 0v to ground, because the lamp was doing the Bonding...
That was a fun one to diagnose! Lol
@@ke6gwf I ran into one of those situations as well. It was a golf course under construction, and there was 120V on the neutral, so the utility company refused to install a remote metering transponder. I started poking around and noticed the 600-120/208 transformer didn't have a bonded neutral. Shut it down, installed the bond, then powered it back up. A breaker for an underground feeder to a remote panel tripped on power up. The cable got mashed somewhere by a piece of equipment. The crew chief was pretty miffed that a panel was out of commission, and didn't handle the explanation very well that the original installing electrician missed something. If the neutral was bonded from the start, the breaker would have tripped when the cable was hit.
@@abpsd73 good detective work! Lol
My story was an industrial machine room that was fed with 3 phase and then had a floor transformer to provide the 110/220v panel supply, and I discovered it by melting the tip off a screwdriver that bridged a ground strip to a cabinet case one evening, but then when I tried to test it and figure out why the next day, everything appeared normal!
It took me a few days until I was in the room at dusk and heard the lighting contactor clunk that I made the connection and then discovered that I could make it flip when I turned the correct breaker off and on.
The site rep didn't believe me, didn't think it was possible, so I shut a breaker off, and clipped a jumper wire from the hot terminal directly to the ground buss, and said "watch this!" and flipped the breaker on while he screamed at me to stop!
Then after nothing happened, I used the tester to show him how the voltage was flipping, and he finally agreed to get the regular electrician to come in, and I guess he was embarrassed when he was told he hadn't bonded the transformer lol
(I was dealing with the industrial automation systems.)
While a lightening strike is absolutely made much more manageable and safer by ground rods ,there is another vital function of ground rods taking place continuously and is arguably equally as important. Grounding maintains an equipotential between structures and power lines as a counter to induced voltage from power lines AND from neutral/center tap drift created by unbalanced loads. This second function of a good inter-system ground is worth explaining too. That was an excellent explanation. I might also add that in tight rural and city areas the multiple paths to ground can be of such low impedance (metal sewer and water systems and several other possibilities) that the returning neutral current will split and be shared between the neutral service conductor and the building/neighborhood total ground paths. I have measured it and it is actually very common for a significant amount of Return/Neutral Current to use an excellent groundpath back to the Utility Source.
What about using a ground rod to take away high frequency noise. For example using one to protect the driving electronics of a CNC plasma table from the HF of the plasma torch?
This channel is pure gold. Thanks!
In the UK some properties use them as ground as the supplier is not obliged to provide one. It's called a TT system
There are much higher requirements for resistance of such grounding device though, you have to test it to make sure there will be enough current to trip the breaker as well as to not create voltage divider with middle point higher than some specific value.
Good point. I had thought these systems were largely used in remote locations because of higher cost for wire. However I since learned that with RCD/GFCI protection, TT grounding is safe and also less prone to EM interference from other devices on the line. I'm told that TT grounding is common in Japan.
@@Mr.Leeroy Yes that is correct I was just keeping simple, In a past life I used to do ECIRs and occasionally had TT installations in rural areas and would pray for acceptable results😂
This is true for the grounding system pictured (TNCS?), but I think for a TT earthed system it IS the fault path. Restiance is still high which is why residual current/ground fault circuit breakers are needed.
Do they even have TN/TT classification in Americas?
saw an air conditioner flow 8 amps through earth @ 180v (from the 230v supply), that's around 6 ohms impedance (TT). The neutral fuse had blown and the wires had melted, shorting the earth cable to the neutral. The compressor started failing but god knows for how long it ran like that
Having just re-installed a new meter base and added a exterior 200 amp breaker panel to meet current NEC code due to a faulty meter that seemed hell bent on setting the side of my house on fire, they will make you install (2) 5/8 x 8ft ground electrodes at least 6 ft apart and the #4 ground wire is to be installed in one continuous run into the main service panel for low impedance purposes. Don't forget your antioxidant paste for the 4/0 & 2/0 aluminum cables 😉
My house was built from scratch during the late 70's so things have changed a bit code wise since then like separating the neutrals and grounds on their own bus bars. Honestly, I don't really see the point of that since the neutral and grounding (safety neutral) wires are linked to the center-tap of the transformer. It looks a little neater, that's all I can say.
I was on generator power for 11 days waiting for the parts to arrive for the install. Wasn't going to let some local electrician price gouge me for $500 - $1,000 to install something that took less than a day.
Passed my electrical inspection with ease which cost me $125 which wasn't to bad considering.
I also now have a spare meter box and breaker panel in my shop just in case something like this ever happens again so I'm able to strip the guts out of the old box and make the repair in less than an hour 😊
As for the grounding rods, most people don't know that for the most part they are really for lightning and static build-up. Now the exception to this is a fence charger which electrifies fence and when touched finds it's way back to the charger via a grounding rod. The more grounding electrodes you install the more powerful a shock they can deliver which is what keeps livestock from escaping 😜
Sir your channel is the best channel ever
Your have left something very important in your explanation..for all this to work , that ground rod have to be tested. Some guys would think that install a 10’ ground rod is the solution. The fact is that sometimes you need to go 80’ in the ground before your impedance go down to 20 ohms.. is you don’t test the grounding electrode, make sure you have a good insurance.
Agree. It has to be in conductive ground like wet clay and not dry gravel. A ground test with a Megger is advisable.
Great simple explanation to wake people up to the fact that "electricity goes ground" is false and incorrect. I encourage everyone to look at Mike Holt's videos to get an in-depth knowledge of grounding.
In essence the "ground wire" is there to clear a fault in an over current condition which sets the circuit breaker.
The ground rod (or metal water pipe) it self is there to dissipate a high frequency, high energy DC pulse to the earth which is induced on all metallic parts in a building when lightning strike occurs near by.
Great
Ground wire is to protect to from metal boxes, enclosures, cases, etc from being energized and ready to shock/kill someone. The ground wire is for protection of people. GFCI does a similar thing but measures the current path and trips at very low current going through ground or a person.
i was a lineman for the local municipal power company for 40 yrs and we put in a lot of ground rods.
No you don’t, the apprentice does. 😉
@@shockcoach yes, if i had one to do it, but lineman had to do it too.
@@shockcoach one time we had a big bunch of them stolen from our yard by some copper hounds but they were only 8 ft. long copper clad rods. they took about 100. friggin clowns.
Saying "electricity always wants to return to its source" and that "the source of lightning is essentially the Earth" is not only confusing but not totally accurate.
Sounds accurate to us.
@@tedlahm5740 I prefer more accurate information, especially from an engineering channel. But you do you.
Correct. I don’t think that’s the reason. It’s because the lightning deposits charged particles on the bare (not insulated) wires of the distribution line when the lightning strikes them. Like charges repel. Also, the Earth is neutrally charged, as in having zero net charge, meaning it doesn't attract nor repel charges on its own. Therefore, the additional charges in the wires repel each other. But since there is a path for the Earth ground through the ground rod, the excess charges can and thus will flow through that path.
@@jimhabsfan Thank you. And a lightning rod does not catch lightning.
Totally agreed. As a physics professor I've got triggered by those statements.
So a friend of mine wanted to put lights in some of the palm trees around his property 3 acres ran wiring to the trees so we could use the maximum amount of wire with the least amount purchase twisted all three wires in the Romax together. Then ran a neutral from the light down the palm tree and into the ground with a 6 foot piece of rebar. This worked very well for 30 years with no adverse effects.
It would certainly work, not sure if electrical meters are done differently elsewhere but without a neutral back to the meter I think your friend wouldn't be paying for the juice to power those lights?
The meter is in the hot wires, not the neutral. The neutral passes straight through the meter base to the main panel.
If I'm understanding this right, your friend would have been paying to slightly heat the earth between the rebar and his meter.
This explanation shattered the myth I have from my childhood ❤️
👍🏼 Recently installed one for a portable generator to be used for emergency power in an outage. 😎✌🏼
Dear author! Thank's a lot for this video! Good luck to you!
Allways to the point, thank you for your work :)
Hi. Thank you for the wonderful explainers you have. Do you have an explainer for preventing house fires because of lightening strikes?
Not currently, good idea though
@@EngineeringMindset I have been trying to gather some good information about this topic. But have not been successful so far.
@@EngineeringMindset ⚡"Currently" -- 😅👍🏼
Nice one, Paul! 😎✌🏼
Electricity DOES NOT take the "preferred path" to source, it takes ALL PATHS back to source.
This hundred + year old misunderstanding was finally corrected 20 some odd years ago and still many teach it incorrectly.
The "preferred" path is the one with the lowest impedance.
Great simple understanding, Thank you!
This is a gem.
Howdy. Nice explanation.
However. Less is discussed about the purpose of the soil rod.
The main purpose is to provide a reference null potential. This null potential is then distributed to plumbing, appliances, concrete rebars and so on via the ground wiring (green). Potential equalizing of touchable parts.
Observe that the reference null is not soil null during a ground fault in an appliance. The soil impedance will cause the reference null to rise above the global soil null. But the environment of utilization potential will rise alongside the reference null through bonding. The fault touch voltage between the faulting aplliance and the concrete floor will be smaller.
So. The rod reference null is not heavily bonded to the global soil null. The best way to provide reference null is not to use just one rod. Use several rods around the house. This will encircle the environment of utilization for best fault potential equalizaton. Better still. Bury a copper wire around the house and connect both ends to the service panel bonding.
Regards.
Can you explain more about how the source of lightning is actually the earth?
I was pondering over that point as well. Doesn't seem correct, since lightning can also occur between clouds having a difference of electrical potential.
The earth is the positive, I believe he is referring to cloud to ground lightening no cloud to cloud. @@SMac-bq8sk
This is a kind of video I'm not looking for but i need it.
The fact that the GFCI picks up the parallel path saves our lives. Even with higher resistance. When your GFCI is tripping be sure to find out why!
This guy knows his stuff
Never explained better. However this explains also why the European system is safer in case a hot wire connect to the ground, they have a "life switch" set to 30mA that would trigger the breaker and interrupt the power from the source 👍🏻
Thank you deep-heartedly!
Can you do a video on why "electricity always tries to return to it's source"
My understanding is that "electrical current will flow from a point of higher electrical potential to a point of lower potential" but I constantly see this trumped by the first rule and would love to know how it works. Thanks.
A battery's high electrical potential is the +ve terminal and low potential is negative terminal.
there are two types of electrical charge to be considered: in static electricity, you have a "positive" or "negative" charge stored, which seeks to discharge to a point of opposite polarity. this includes lightning and capacitors.
in electrical systems that you get work out of, you have an electrical source, whether a battery or a generator. in either case, it has to be a complete circuit to be usable - which means electricity must flow out from the source, through the load, and back to the source; much like a bicycle chain. it has to be a complete loop to propel the bicycle.
The 'source' rule never need 'trump' the potential rule.
Potential is relative. A source internally generates a difference of potential--by definition
If current did not return to the source (in time) then that implies a charge is building up elsewhere (which can happen), but this then implies that there is a new differential elsewhere that 'wants' to equalize, and it wants to do so with the source.
Consider that charge, in the context of power circuits, needs to be constantly replenished--be it by a spinning turbine, a chemical reaction, or photons (photoelectric effect). Where is the charge going to be replenished from? Can it be stolen from some bank? Well if it steels charge, that 'charge hole' will want to be filled. Consider that happening on a contiguous basis and you have a continuous circuit with charge 'returning to source.'
Thank you.. And it's good because it's short video.
Thanks for the info.. now i know why everytime that a lightening is happening here in the farm.. the wire that connected to the ground rod is a having a sparks...
I'm gonna be studying this groundbreaking video for the next 20 years
if the grounded conductor between the panel and the transformer fails, the hope is that the grounding electrode will carry enough current to keep the resulting voltage imbalance from being disastrous. it is also used to provide a reference for "zero" volts to ground in the grounded portion of the electrical system. lightning arrester electrode systems are completely SEPARATE from the grounding electrode system.
this is also different from an equipotential bonding system which is there to make sure all non current carrying conductive material is at "ground" potential.
i was trying to find a polite way of disagreeing with Paul(makers of vid) but you beat me to it. my experience of 45 years teaching upcoming electricians in the field i try to make sure they know the important things that will save lives. one of which is that ground rod (which new NEC code says 2 grounds rods have to be installed) as Ken said is not intended for lightning although it could dissipate some minor strikes, its purpose is to keep a reference to ground. if you lose your neutral an imbalance of voltage can occur(voltage goes down ,current goes up, fries stuff. also i tell them be very carful when disconnecting a ground rod,if it does have a neutral problem could get a big spark when disconnecting.Pauls still a smart guy
Separate according to whom?
@@jeffkardosjr.3825 pretty much every code there is.
Interesting and very informative.
Ground rod also keeps the neutral point at 0V . Correct me if I am wrong.
Not quite. It’s the neutral/earth connection that keeps the neutral point at 0 or earth potential.
I dug up a raised flower bed and uncovered my grounding rod. I should sledgehammer it farther down to cover it back up, correct?
Well explained..
i really enjoy ur short video, nice work :)
future video idea: tesla coil
Always clear knowledge and interestingly ground rods just can't be placed anywhere and using more than one changes the resistance but some people already knew that
I just whacked in a ground rod last week, perfect timing :D
Thanks paul
Funny coincidence, I just got this recommended to me the day after I just bought a ground rod with my dad for our new property!!
😂😂 Awesome Coincidence 😂😂
Short and very informative
Thank you
Questions: my system is DIY. Where are you attaching the ground wire and rod to? My area suffers a lot of lightning. A strike a couple of years ago flipped the circuit breaker, but to no avail, and damaged more things than I could afford to replace. These rods are rare in Australia.
If the neutral and grounding bar is connected are connected to ground then how does landing a hot wire on the ground rod have only the path of high resistance through the ground rods and not through the grounding conductor through the transformer
Very informative video. Can we grow any plants like flowers, vegetable or tree near the grounding rods?
I think people are missing the fact that current will flow to the ground rod, not earth. Earth might have high impedance but the lightning rod is providing safe path for ground faults as it is a good conductor.
Just watching that make me a certified...
Finally!! Excellent video my friend
Why is the black hot leg wire at the lamp socket not connected / landed on the socket base terminal as is now shown in the video? Why is the socket's base ground wire shown in yellow instead of green per USA NEC Code?
Would be great if you did some ship specific electrical engineering videos like insulated neutral earthing and distribution systems
Actually I would add something to the video was missed which during lightning there is something add to protect against like lightning protection and surge protection. The part will allow the high current to go to the ground during the fault of lightning on the load or transformer sides called surge protection which allow that high current to discharge in the ground. And during the ground fault I would add also something I believe what mean in the video is a high resistance grounding system which most of the time the user install to provide a continuous operation during faults (for some costumer operation needs).
Well explained.
here in Denmark most households use TT system, however places like in the city, were its not possible to burry a rod in the ground due to asphalt they use TN system which is just the transformer stations ground rod ( N ) as i understand
I just realized a lighting strike is just a big arc between the clouds and the earth's soil...mind blown
Thanks for sharing it with us
You see in Australia, fault current WILL flow to earth rod.
That's because in the main switchboard, Neutral is tied to Earth rod.
That link is called multiplied earth neutral (MEN).
If neutral in the mains develops high resistance, or is cut, all current goes from phase to earth rod and back to transformer.
Very dangerous situation, since all appliances that are earth will have high potential on them.
Electrical engineer here, the ground is negatively charged and the atmosphere is positive, meaning there's a surplus of electricity in the air as opposed to the ground and it needs somewhere to go other than elsewhere in the atmosphere. That's why the grounding wire is always black aka ground not hot though technically all wires are to be assessed as hot. So when you have a lightning strike you want that electricity to have the path of least resistance where it can be disapated back to the earth.
Depents on the network you use
TT
IT
TN-C
TN-C-S
TN-S
So is there an advantage to having 2 grounding rods, from ground out of panel box ? Connected with continuous ground wire.
In some soil conditions multiple grounding rods, or complex grounding networks, may be required, in super dry soil, shallow bedrock etc.
There are specs for how good the connection is between the earth and the ground rod, and if it doesn't pass something more will have to be done.
Explain well
Nice, we probably need a video on LCDs.
Electricity flows through all paths of resistance.
But not equally. More current through the lower impedance path.
Could you do a short video explaining Kirchhoff's Law?
Electricity is fascinating, but what is the return path mechanism of a lightning strike, be it from sky to ground, or sky to sky??
Nicely explained.
Actually, electricity follows ALL paths of resistance. Just more current in lower resistance.
Very interested information.
Nice, my copper wires burned through. I knew it had been lightening and I made sure to fix it. Now I understand why.
Can’t go wrong with a 2 min video
Thanks brother ,
Lightning strikes in the primary or HV will not be discharged in the neutral grounded. Best protection is a surge arresters
I have no idea what he said 😂😂😂😂😂
Well explained
So, if under normal circumstances,, the main service neutral came loose and fell off of it's lug....would the return current just travel down the ground rod, through the ground and up the ground rod connected to the transformer and everything would continue working? I guess not because ohms law means the high resistance of the ground would mean low amps and things would crazy dim...so we would know the main neutral wire fell off the lug. Do I have this correct?
I thought ground wire protects from electrocution as currents prefers to travel into the ground instead of human body(more resistance)? Am I correct?
Thank you.
Big fan Thanks for this video
Sir please do make a video on earthing tutorial...how to make good earthing for domestic or industriak
Can the grounding cable or rod ever get hot?
Would you be able to do a short video explaining what difference is between Volt Free Contact and Dry Contact? A lot of people seem to confuse these two. Thanks
What do you mean, "seem to confuse these two"? They are synonymous.