Station Grounding & Extra Class License Question That Has The Wrong Answers Part 1 of 2

This is Part 1 of 2 parts that shows Jim"s somewhat messy but effective station ground. Jim also discusses a Question on the Extra Class Exam that is wrong. Jim also discusses how adding a ground rod to the station may be a violation of the National Electric Code.

[@713allen]

I agree. In a high-energy event -- high voltage, high current, high frequency pulse -- such as a lightning strike, it is unrealistic to believe that the puny #6 wire running to the grounding rod is nothing more than a fast-blow fuse. The question's correct answer is "none of the above." The ONLY function and purpose of the grounding-rod-to-#6-wire-to-breaker-box-cabinet-to-house-wiring-grounds-block-and-single-wire-to-the-neutral-common-block is to assure that the reference potential for the house circuits are at the IMMEDIATE LOCAL ground potential. For most homes, the wires running from the pole -- pole-grounded bare wire, insulated transformer neutral and 110VAC P1 and P2 -- may be a significant distance from the home. Thus the reference ground potential, at the pole to which the transformer center-tap-neutral is tied, may be significantly different than the local ground potential at the home. The house rod and grounding circuit in the mains box assures that the home is strongly tied to the local ground potential and not "floating" at some far-away reference potential. The rod circuit is not a high current carrying circuit (for a lightning strike) but rather a very conservative, low resistance safety-centric ground reference for folks in the house. It is important to emphasize that the NEC-dictated ground rod circuit as described above addresses the safety and power needs for 60hz power. A lightning strike or RF flow requires a different analysis, needs and treatment. NFPA 780 dictates for lightning rod installations are an addition to and have specific ties into the NEC electrical safety system. But that lightning strike treatment addition does not modify in any way the rod-mains-box safety circuit dictated by the NEC.

[@713allen]

Before someone comments....my old house has four wires from the pole (P1, P2, insulated netural and bare-wire ground). Most newer homes have 2 insulated power legs and a bare-wire neutral that is grounded at the pole. And grounded again at the house's power breaker box.

[@g0fvt]

Although I live in a different jurisdiction with different wiring regs I do share the same physics. It is a very bad question, and the lost mark in the examination is the least of the problems with it. Arbitrarily adding grounds is an unsafe practice if they are not correctly bonded to the safety ground. Sadly people will refer to their licensing questions when they set up their station. Including a question like this will do more harm than good. Great video as always 73

[@PeopleAlreadyDidThis]

Right, the rod certainly cannot affect the dome of protection. In reading as much published literature as I can regarding station grounding, I’ve turned up one important and relevant idea, IMO. Ignoring AC line fault safety and RF grounds for the moment, the idea regarding lightning is to keep strike-induced voltage potentials as near earth ground potential as possible and as equal as possible between pieces of station equipment. Bonding all equipment to earth with adequate gauge wire to mitigate (but not necessarily eliminate) brief high voltage strike potentials lowers the chance that your rig’s chassis is elevated hundreds or thousands of volts above earth ground potential, or above that of a neighboring piece of equipment. The goal is to keep high induced voltages as low as possible, and keep them the same across all your gear and earth. You’re trying to eliminate dangerous voltage differentials. Yes, your rigs might already be grounded via the AC safety ground in the house wiring, but it is typically a 12 or 14 gauge wire that has too much DC resistance and too much RF inductive reactance to be of any use in the case of a kilovolts-surge caused by lightning that has a huge RF component. Earth ground is not “zero.” Its potential changes and can rise high during a nearby strike. If your gear isn’t soundly grounded, it will rise higher, creating a dangerous differential. If you receive a direct strike, you’re toast. No 6 gauge wire can conduct that kind of current. We’re talking about reducing damage and potential injury from induced voltage caused by indirect strikes. Read the ARRL grounding and bonding book. It’s a good place to start. So no, a ground rod cannot “protect you from a strike,” as in starship Enterprise shields in the sky. It can offer some or much protection from the secondary effects of a nearby strike, depending on the voltage induced. In that sense, and given the other possible answers, “lightning protection” seems a primary purpose. One further analogy...seat belts protect you, but they don’t protect from car crashes happening. So they do and don’t offer crash protection, depending on your way of seeing things.

[@ham-radio]

The questions as written without interpretation just asks in a weird way about a driven rod. The question as written and the answer as written are wrong; dead wrong. I was not intending to cover how to install ground rods for lightning. My concern is violating the NEC and creating a dangerous installation. We could talk for hours about lightning. Thanks & 73, Jim

[@DK5ONV]

Hello Jim! You brought it all to the Table and I could not explain this any better than you did. Station Grounding and Electrical Safety is Priority #1 before going on air. Thx for another great documentary video. Merry x-mas & many health for you. Hope to work you on 80 and 40m. 73's de Günter

[@slshock]

In my opinion, the question is referring to an "external" driven ground rod which is separate from the structures main panel "safety" ground rod, which is the equipment safety ground found in the structures ac receptacles. The purpose of this extra, dedicated, earth connection, is to help reduce the difference in potential to as close to zero as possible which will help "minimize" a lightening strike from occurring in the first place. This is why the National Fire Protection Association (NFPA) recommends disconnecting and "grounding" all antennas to an "external" grounding rod; this includes both conductors. They also recommend unplugging all equipment from the ac power source. This is the jest of the question.

[@ham-radio]

Thank you. I am glad that you took the time to write what you think they (the VEC) were asking. The question for you means external ground rod at a tower or structure. The common/typical ground rod is also external. The Ufer would not apply. Also, think about how the NEC required ground rods to be connected when placed at an antenna structure. Additionally, consider that most hams do not have a tower. The question ask about the primary purpose of a (singular) ground rod. The purpose is safety. In either case, the question is poorly written and the antenna is not correct. Again, look at the drawings that show the NEC requirement for ground rods. As a Building Inspector and member of County committees that wrote the codes (UPC, NEC, etc), Expert Witness and the rest of the stuff that I did, I still come back to the ground rod at the main. Thanks & 73, Jim

[@slshock]

@@ham-radio I do agree with you that the question is very poorly written and the fact that it is listed under Sub Element E0, Safety. I was only considering the ground rod that most hams have right outside their radio room and not the rods at the tower or antenna structure, even though the NEC suggests bonding all grounds to the service entrance ground. The single point ground in the shack that is bonded to the external ground rod right outside the radio room is not considered the "safety equipment ground" that is used to protect a person from electrical shock. (This is why you shouldn't defeat the safety grounding prong on the end of a power cord as you mentioned). This external ground is used to drain stray currents such as static and the like, which in turn will help minimize the risk of a lightning strike. This is how I interpreted the question even though all grounding and bonding could be considered as safety. Thanks for your videos. I do enjoy them. 73

[@glennstanfield5855]

To me that is the BEST answer presented because it is the only answer that is even remotely safety related. Still a great video.

[@weinerdog137]

Love your expertise. Grounding has been confusing people for a long time. Made worse by "safety Sally" and "Ego Eric"

[@ham-radio]

Jason, maybe you could send an email to me sometime and tell me who those two are. 73, Jim

[@weinerdog137]

@@ham-radio lol. What band are you active on? No licence but recently listening on a k2 and random length dipole. 40 m seems good today.

[@HamRadioLiveShow]

ANOTHER great video Jim! Well done.

[@DK5ONV]

Hi Larry, happy monday afternoon into OR-State. 73's de Günter

[@2metercrew389]

Another great video Jim... just had my house totally re-wired two years ago and they added 2 8 foot ground rods on each side of the house...

[@flyingjeff1984]

Are they connected to each other? They should be. One grounding system. The more rods the merrier.

[@2metercrew389]

@@flyingjeff1984 yes they are there is a piece of copper going from one ground rod on one side of the house to the other ground rod near the breaker box

[@flyingjeff1984]

@@2metercrew389 I'm trying to get up the guts to buy 2 or 300 feet of wire and do just that. I'm restricted to going the long way. :(

[@falsedragon33]

We do halo grounding in our cellular sites. We don't use rod, but rather flat copper plate buried by each face of the building. Those 4 points are brought into the shelter and connect to a busbar that circles the room. Each peice of equipment takes the shortest route to the grounding bar. Everything metal gets grounded. On the outside a small bar is extended that bonds the shield of ever peice of coax that goes up the tower. Why? To create that so called bubble of protection. Some sites get hit hundreds of times a year, and still need a 99.9% uptime. Sometimes, expecially in the Rocky parts of the mountains, it gets difficult, as the ground isn't much of a ground. I have always said, lighting is like a punch to a boxer. If you want to play, you better be able to take a hit.

[@ham-radio]

That sounds really good. Also, since that is a separate building, NEC does allow a separate ground. Interesting about the bubble of prevention. Thanks for the information Mike.73, Jim W6LG in Rocklin, Ca

[@briangreen7797]

Hello Jim, At the ripe age of 70, I have decided to become a radio ham. I really appreciate your talks which I find interesting. Concerning radio protection. Do you think that the question could be referring to having a proper earthing system employed on the roof of a building connected directly to the earth rod in the ground? ; and the case of an UHF antenna secured up a mast being connected to an '"N" Type coaxial connector employing a (RFS Cellflex for example) solid copper outer under the outer coaxial cable casing. At the bottom of the mast on the roof a strip of the outer Co-axial cable casing is removed from around the coaxial cable and a special lightening conductor fitting is clamped and secured around the cable, which is then protected by being wrapped with self amalgamating tape, then covered with 'plumbers mate' to protect the connection and make it waterproof. The threaded stud of the special lightening conductor fitting to the coaxial cable is connected directly via an earthing strap to a special earthing system clamp to the earthing system tape on the roof, thus giving a direct connection from the antenna cable at the bottom of the mast on the roof to the ground. I can't remember if the antenna cable came into the building through an earthed bulkhead feedthrough connector or not. The antenna co-axial cable came into the radio room of the building and was connected to the input of a four stage earthed Helical Filter in the rack to the radio base station. Apparently my brother told me that there was a lightening strike, and that he had been very lucky as it had not damage his base station equipment. He believes that the Helical Filter made by Aerial Facilities Ltd (similar type as seen in Fig 9.14 on page 509 in Handbook of Filter Synthesis by Anatol I. Zverev) protected the base station equipment from damage, there not being a direct connection between the antenna cable inner and the base station equipment.

[@1fanger888]

Hey Jim. Thanks. I pick up stuff I should know already, from listening to you. Being in the trades for so long, I understand that people know some things that just ain`t so. The only real way to protect your rig is to listen to the weather report and un plug EVERYTHING at the smallest threat of electrical activity. Lightning rods, earth connections, etc., will not save the bacon. Insuring your stuff will help, but the loss of a cherished rig with a lot of memories attached to it may be an incalculable loss. I was told that lightning can even strike a ground rod and the juice can travel back to the fuse box. KC3BXZ Joe 73

[@DonHavjuan]

Agree. That's absolutely not the primary purpose of a ground rod. It might not even help at all. The answer from those options is D, if it assumes the alternative is to use your home wiring earth back at your wiring box.

[@Larry4098]

National ELECTRICAL Code. Not electric. 😀 Thanks for all you do.

[@thork0tjt515]

Very informative! As a fairly new ham, this subject is very concerning, and confusing to me. Thank you Jim. Hope things are well for you! 73

[@VictorDenisov]

It looks like there is a misunderstanding of a poorly phrased question. If we read the section in the extra class manual that describes this question (section 11.3 page 11-8) they are talking about grounding towers. This is what they mean by external earth connection. I have to admit from the question alone it's difficult to make out what they meant.

[@rudert56]

We are in the process of building a house on a peninsula in a large lake. Three neighbor’s houses have been hit by lightning in the last two years (and they aren’t hams). I have driven 24 ground rods and bonded them, the tower and power and Ufer grounds together. Wish me luck.

[@MrWirebrain]

You need to make the point that the ground rod is driven at the home at the main panel for a reason. It is to complete a circuit to the grounding system at the transformer if the neutral conductor to the main panel is broken or lost. That ground reference point should be enough to open circuit breakers if there is a dead short in a device powered by the main panel. All of those other devices tapping onto the ground are using it for noise cancellation and grounding code conformity. The ground rod also serves to dump high voltage from a lightning strike into the ground as soon as possible avoiding the transformer and the high voltage side of the system.

[@ham-radio]

Hello Joe, A couple of questions: Are you familiar with the NEC requirements? With reference to a driven rod at that station that is remote from the main panel and several ohms that is above ground; maybe 2 or 3 volts, do you believe that it is in compliance with the intent of the NEC with respect to grounding? I agree about the driven rod of Ufer ground that is part of the common point ground, I failed to fully discuss the electrical service has many grounds all down the line. If a rod is driven at the station and then more rods all leading back to the main panel with a large conduction, would that be okay under the NEC? Thanks, Jim

[@MrWirebrain]

@@ham-radio yes I am familiar with the code. And I also have experience with electrical engineers and inspectors that all interpret this differently. After 40 years as an industrial electrician and machine controls technician I’ve seen it all when it comes to grounding. NEC only recognizes one central ground point At the service entrance. I believe if all these ground points are properly tied together there should be no voltage difference at these points. All of this grounding I see under your table really has nothing to do with the electrical grounding of your devices that apply to your service entrance. This grounding is to illuminate floating RF energy and lightning protection. Lightning always finds the point of least resistance to get back to the earth. With absolute perfect grounding of your radio equipment lighting is going to find your equipment before anything else. There’s been some work done with high resistance grounding in industrial applications. I believe this is to avoid lightning strikes and reduce equipment damage due to the high current capabilities of a low resistance ground circuit. This is why so many branch circuits in industrial applications have gone to GFI capabilities. I really enjoy your videos and appreciate what you’re doing for the ham community and myself.

[@glenmartin2437]

I agree that this is a bad question and also in many ways confusing. There is so much misinformation and disinformation concerning grounding and bonding that the question should be omitted. Lightning protection is separate from the electrical ground. It is based on a cone of defense over the area to be protected. The ground rod for the electrical system is to protect the electrical system. The building electrical ground is tied to the neutral line near the entrance of the line into the edifice, that is, the drop line, the meter housing, or junction box. If there is a line fault, the ground line carries enough current to flip the circuit breaker off. This protects the building from fire and may reduce or prevent an electrocution. Although the electrical system ground is connected to the earth by a ground rod or ufer ground, this alternate path does not provide enough current flow to throw the breaker. See videos by Mike Holt and others. GFCI devices reduce electrocutions better than a circuit breaker which may take seconds to respond before flipping the power off. I am a retired research professor and I have been asking questions and studying grounding since I was a child. I still have plenty of questions and am perplexed with all the misinformation and disinformation that persists.

[@richardnalisnick462]

Great Video. I have been a Ham over 27 years and enjoy your channel. 73's W3AMT

[@ham-radio]

Thank you very much! 73, Jim W6LG

[@davidwilcox9110]

Yes, I have an “internal” earth connection. I drove an 8’ ground rod in the corner of my ham station area before they poured the concrete floor. Ha!

[@johnbauman4005]

So where do I get one of those lightning protection domes you're talking about? John - KK7JBZ

[@1shARyn3]

No ground ROD connected to our service panel. All neighborhood electric is buried with cables running in buried steel conduit (which acts as the ground). All external entities are bonded to the service panel. My station is the only ground ROD on the pemises (and also has a bonding wire run to the service panel)

[@ham-radio]

Hi, I have never seen that. We have buried services and per the NEC, each residence has a ground or earth. Our is an Ufer. So, there is no common point box below or near the panel. No box with 4 screws that has all of the "stuff" that comes into the house. I have never seen that. Question: Is it possible that there is an Ufer ground? 73, Jim

[@beekeeper8474]

Thanks for all the info! That question bothered me but I aced my extra test. I been trying to find out if bonding through copper water piping is okay? My new house has three but all tied into the pipes. I can't get a straight answer from my local electricians.

[@TomJones-uf5sl]

Bonding and grounding to copper pipes which enter the ground is an old fashioned but still effective way to get an earth connection. A grounding rod driven into moist earth is still the preferred way to ground your house today.

[@beekeeper8474]

There is three ground rods around my house but each one is tied into the water spigot exiting the house and one in the main power box but the bonding if I'm using the term right is by the copper plumbing

[@paulhirschman2641]

To my Elmer, Always better off from having listened to you! Again, thanks for your kindness. W4PMH

[@angelhelp6819]

Hi Jimmy I like that video what you talking about it's very excellent and I'm glad you came back to talk to more videos and I will see you on your very well take care of your health and hope you see you all the time on KZbin I like your videos

[@neilgelinas9926]

Hi Jim. I am just getting into HAM. I am looking at this from an electricians view. So yes a Primary Ground is to divert a lightening strike into ground. Forget anything else. Yes your sensitive equipment could be damaged but the Primary Ground is to divert thousands and thousands of volts away from your house. You are looking into this question too focused.

[@713allen]

I don't think the puny #6 wire connected to the ground rod will divert away a significant amount of the energy from a lightning strike before it becomes a fast-blow fuse. Lightning energy dispersion systems are usually constructed of very heavy materials, i.e. copper wire 1/2 to 1 inch in diameter and installed with large radius bends to reduce self-inductive impedances failures associated with the huge current flows. I don't think anything in the NEC suggests that they power system ground rod is part of a lightning strike system.

[@DEplinker]

I disagree. First, let me say and thank you for the videos you do. You are brilliant in your knowledge and understanding, and ability to communicate both. So why do I disagree? Let me begin where I agree. Exceptions notwithstanding, consistent with the NEC, all grounds must be bonded at the service. Agreed. Consistent with the Motorola R56 standard, grounding (earthing) *Will* protect from lightning. That said, a single ground rod isn't even close to being able to achieve that. So I agree, lightning protection is not a good answer. Grounding in the structure is for safety; however, as the question deals with an external ground, I don't see electrical safety to be the application. As I understand, we must choose from the best possible answer from those answers that are giving us. So now, we are left with choosing... which really is the best possible answer?

[@ham-radio]

Thank you for all. Is there an answer that you would have chosen? Some of the comments have dealt with, as you did, external ground. Here's that terrible question: What is the primary function of an external earth connection or ground rod? A. Reduce received noise B. Lightning protection C. Reduce RF current flow between pieces of equipment D. Reduce RFI to telephones and home entertainment systems The question has "or" and that bothered me. Every ground rod that I inspected was an external earth connection. I wondered about external as opposed to internal and could not figure out what they trying to ask. Answer C was the closest to something that made sense to me. One idea I had was the driven rod at the station which could or could not be installed correctly according the NEC that I used to carry in my County truck. If nothing else, a lot of us have had time to reflect on the ground rod. In light of all that is happening around us in the U.S., it was nice to divert attention to the lowly ground rod. The overall test for the Extra is not what I would like to see. Thanks again for your kind and generous comments. Taking the time to write to me is really appreciated by everyone. Next year it will be 57 years (March) with a license and there is so much more that I still would like to learn about. 73, Jim dit dit

[@DEplinker]

@@ham-radio You're right, the conjunction “or” here could be problematic. Given the current choices, I'm glad that you found “C” making the most sense to you, because that was my choice here. I'm a general who got his technician almost year ago. I need to buckle down and start studying for my extra, but I prefer learning things organically, which is primarily how I passed both my tech and general. I will continue to do that after I am granted an extra, but it's going to take too long for me to learn what's necessary to pass that exam without first studying. When setting up my station this year, I spent a lot of time focusing on grounding and the NEC. Mike Holt was valuable with some of that. Now retired, I can do some of things I wanted to do, but didn't have the time. In addition to reading and self-educating, there are people who have been instrumental in increasing my knowledge. You one, Jim, and I really appreciate the time that you take doing the things you do to educate folks like me. 73, Michael K4KKK

[@davidkerr8030]

Thanks for the clarification - I would also disagree with the "official" answer to the question. There are however some important (non-USA, I think) exceptions. Here in the UK, many houses have Protective Multiple Earth (PME) systems, where the neutral line is tied back with all the others on the street to earth by the electricity supplier. Thus introducing a local ground in your shack can thus be very dangerous! Always check with your supply company first. David 2E0FXO

[@713allen]

In the US, the power lines at the pole often/usually have four wires -- three HV 120deg power phases and one bare inter-pole "ground" wire. At each pole, the ground wire usually has a #6 solid bare copper wire running down the pole and into the ground. This treatment acknowledges that ground potential is not necessarily a constant V along the route. It serves to reduce any ground currents under the pole by connecting the zone at the base of the pole to the same potential and close to the same potential as the neighboring pole. The typical pole transformer has its center-tap tied to the inter-pole ground wire and thus to the local pole-base ground potential. To the house usually four wires are run: two 100amp 110VAC P1 and P2, one 100amp neutral and one bare pole-grounded, supporting guy wire. At the house mains box, the bare ground is tied to a ground block and the box itself. An external house-local ground rod is tied to this ground block. The incoming neutral is tied to a neutral ground block. All the house wiring neutrals return to this block. In the mains box, a single wire runs between the ground block and the neutral block. This single wire ties the local ground reference the house's neutral voltage level. All this keeps the house grounds at a local ground. It also keeps the incoming neutral at the local ground. Note that the neutral at the wall socket may not be at local ground because current flow in the neutral wire back to the mains box does the V=IR thing.

[@KeiranR]

I of 2?

[@AB1Vampire]

The key to that question is the word "external".

[@ham-radio]

Can you tell us a little more? Thanks, Jim

[@alanjames4526]

Hi, Jim. Another great video. Again, I have added to my ham knowledge base with your help. Looks like you are doing well in spite of covid-19. We are also ok up here and pretty much hunkered down. Maybe we will be able to meet and have breakfast in 2021. 73 Alan KZ6B

[@w4mkh]

I have an 8' copper ground rod at the corner of my house that is only about 10 feet from my equipment. Once I am done with my shack everything will be tied into that.

[@Annie-ot5tq]

BUSH & Trump Inauguration speech in slow motion. "BACKWARDS talk", ALMOST LIKE SHADE, says what they HAVE done to us and what they WILL do to us.Myron C Fagan explains well.

[@expert244]

I have earth grounded my antennas and feedlines, but not my radio equipment. In that sense it is for lightning and static protection.

[@ham-radio]

Thanks. 73, Jim W6LG in Rocklin, Ca

[@ward5821]

The ground rod will make it worse if you do not follow single point grounding theory. When current flows though the ground under our feet, the resistance between the 2 grounds produces a huge voltage drop. That is the opposite of lightning protection. HI HI

[@ham-radio]

Still many, including the ARRL give the wrong advice. 73, Jim

[@firstchoicelastchoice28]

What is AMSAT ? Thanks for a reply.

[@ham-radio]

That could be Amateur Satellite. Google AMSAT and ham radio to see what some guy and gals are doing with satellites. Pretty amazing stuff; 73 Jim

[@firstchoicelastchoice28]

@@ham-radio I was hoping to reach the I.S.S. and have a chat with someone there. And bouncing off the moon....... how to? :) Live and learn.

[@SJHamende]

Great info, but what happened to the end of the video? Seems like I missed something.

[@ham-radio]

Which part? You may have seen just part 1. I pick up from the freeze frame in part 2. 73, Jim W6LG in Rocklin, Ca

[@SJHamende]

@@ham-radio thanks, I will watch art 2, thanks, always good info on your videos.

[@paulhastings3109]

The question on the test should be safety

[@richarde735]

reduce RF between equipment NEC requires bonding to ground and do not want multiple paths to ground and why ALL radios should also be connected to this single grounding point.

[@bille3rd]

Good job!

[@AliReza-zx8km]

Nice...................

[@flyingjeff1984]

More proof that the most difficult type of exam to create is multiple guess.

[@REKlaus]

Not too bad but if you really want to know how and Why, watch this video starting at 28 minutes and then look up Mike Holt's grounding myths.

[@clems6989]

Of those 4 answers it is the "most correct"...

[@ronjarvis8133]

You are not correct. Earth ground is not for electrical safety. The neutral and ground conductors connect to the neutral at the source. The ground conductor in the wire path is the responsible path for fault current. The only reason we have an earth ground to the neutral is to dissapte static charge build up in the eletrical system. Lighting is static charge. A grounded system, ground conductors have different purposes. Unfortunately the word ground gives the wrong perception.

[@ham-radio]

I strongly disagree with you and so do OSHA and the NEC. "Earthing is used to protect you from an electric shock. It does this by providing a path (a protective conductor) for a fault current to flow to earth. It also causes the protective device (either a circuit-breaker or fuse) to switch off the electric current to the circuit that has the fault." "

[@ronjarvis8133]

@@ham-radio Please watch kzbin.info/www/bejne/aafZp6lrhruNpaM a Mike Holt class from NEC training. Sorry it is 30 minutes long. He has a lot of videos classes on grounding and bonding as it applies to the NEC. My early days we spent a lot of time earth grounding communication equipment to help prevent the transient static build up on the power lines from causing the computer parts to fail. Static was a big problem for early integrated circuit and cpu. I enjoy your channel. AI7JF

[@ronjarvis8133]

Still not convinced, read NEC section 250.4 (A) (1). Also read (B) (4) specifically states the earth shall not be considered as an effective ground fault path. I believe because the green wire is called ground that it causes confusion. The green as well as the neutral are grounded conductors because of the bonding to earth at the main panel, but the purpose of the green wire of correct size is to handle fault current back to the source (main Panel) and be able to handle enough instant current to cause the breaker to trip, not melt the wire in the wall. You could take one of your dryer hot leads to the dirt out side and not trip that 60amp breaker but the ground bonding wire (bare) is now energized with enough electrons to hurt someone. My source of knowledge is from completing state electrical and exam a couple years back and ever since it has grabbed my attention when it is talked about.