Ideal dock wiring Questions?

[ballvalve]

Anyone with grounding needs and question might want to save this companys website:

http://stormgrounding.electrical-ins...com/index.html

[jwelectric]

JW... I can assure you that I am not simply being bull headed. There is a reason for my stance on the grounding of boat docks. I may not be able to throw out NEC regulations and I may not be able to explain it in technical terms but apparently it is something unusual to people who are not familiar with this kind of application. Here's the link to the website where Alabama Power owns the lake. Check out the thread and you may see the logic better than I can explain it. If I'm wrong I want to know why because there are lots of linemen and electricians who are doing exactly as I do. Oddly, arguments and situations like this prompted me to get my plumbing license (I made 98% on my licensing exam). Maybe I'll end up with my electrician's license too.
http://www.lakesonline.com/Forum/sho...8&SiteID=AL008

Here once again is someone with an idea that is not a proven fact. The computer chip in the GFCI breaker MUST have the device neutral connected or it WILL NOT WORK PROPERLY.
When this wire is cut then there is no need to even install the device.

If you truly took electronics in school then you know how to figure a parallel circuit. You also know that the total resistance of a parallel circuit will always be less than the smallest resistance in the circuit.
You know that in a series circuit that the total resistance will be all the resistances added together.
With someone in series with the earth the total resistance will be the human plus the earth and the total amount of the current will be through the human in or out of the water.
With a parallel circuit the human will only carry that portion of current that is not carried by the equipment grounding conductor but if that equipment grounding conductor is cut then the human becomes part of a series circuit and carries the blunt force of the faulted current.
This is basic electricity and is taught in the first semester of class.

What you seem to be saying is that current is trying to run to ground or earth which is far from the facts. All electricity follows the same laws of physics. Every electron involved in the circuit must return to its source weather it is through the low resistance of the equipment grounding conductor or the high resistance of earth.

When you cut the equipment grounding conductor and connect it to the driven rod you are forcing the fault current to flow through earth and when someone comes in contact with whatever that becomes energized that person must carry the entire faulted current.

On a side note I live in Piedmont North Carolina where we have several lakes within an hour’s drive from where I live. I have personally wired both private and commercial docks and many of them.
I am also very involved in the education field in both premises wiring (the wiring after the point of delivery from the utility) and electronics.
I am also very involved in the NEC and the education of the NEC. My name is well known in the circle of those involved in the code making process. I am a certified electrical code enforcement instructor and sit on several committees. This can easily be check by simply going to this web site and seeing for yourself.
http://www.nciaei.org/
Look under the Committees then Education Committee as well as under officers and look for the name Mike Whitt, yea that is me.

I helped write the manuals that the NC Dept. of Insurance Qualification Board mandates that instructors use for teaching electrical inspectors for 2002, 2005, and 2008. Without a doubt I will be asked to help write the manuals for the 2011 code cycle also.

Please understand I am not just spinning my wheels but am telling you fact not something someone has thought would work but what has already been proven to be fact. I have devoted my entire life to learning the theory behind electrical current flow not just reading junk someone has posted on some web site that they think will work.

What you propose as what is proposed by that idiot in the web site you posted is nothing but a death trap waiting for someone to get involved. It teeters on being criminal.

[jwelectric]

Anyone with grounding needs and question might want to save this companys website:

http://stormgrounding.electrical-ins...com/index.html

This is not what is being discussed in this thread but thanks for the post

[LOTW]

Several weeks ago I posted a question regarding wiring my boathouse with a single circuit and received much helpful advice. I am interested in this topic, know little about electricity, and have gotten more worried as this thread has increased. Forgive my ignorance, but I have a simple question: How can one receive a "tickle" or some other shock without there being worn insulation or some other access to the current? I understand how dropping an electrical tool into water produces a shock, but how can a person be otherwise "tickled" on a dock unless there is an exposed wire or other "short" which would allow the electricity to reach the dock? And to reduce the risk should a person use both an GFI outlet and a GFI breaker, or just the breaker?

[jwelectric]

This is a very good question and one that will take a moment to answer.

Take a real simple circuit that anyone can understand. We will use one that has a power source, a load, a path, and a switch.
In this circuit all components that are required for current to flow are in place. Once the switch is closed current will leave the power source, pass through the load, and return to the source through the switch and path. In order to see how this circuit works simply open your flashlight and look.

This circuit works without any type of earth ground. Even if one side of the source was connect to earth it would still work and the connection to earth would not shorten the life of the batteries.

The utility company does the same thing with their transmission lines. There will be the ungrounded conductors and one conductor that is intentionally connected to earth. The utility company connects this conductor to earth in order to allow lightning somewhere to go in the event of a direct strike to their lines.

We connect out electrical systems or our premises wiring to earth for the same reason, to give lightning a place to go. This earth grounding in no way interferes with how current flows across lines. On some occasions the power company will use earth as a return path or as the neutral of their systems. These systems are known as SWER or single wire earth return systems.

When the utility company uses the earth as a return path the earth becomes energized. The earth can become energized on the premises wiring system when we lose our neutral. These currents are referred to as “stray currents”

Just as in the flashlight the current must return to its source the current for the transmission lines and the wiring to our buildings must return to their source. These stray currents are looking through earth for some path to which they can return.

Every once and a while you will hear someone make the false statement that current will follow the path of least resistance. Current will take every available path presented to it in order to return to its source. This is the way that every circuit board known to man works. The components of the circuit board will mandate how much current flow through each branch of the board. If current only followed the path of least resistance then the circuit board would be useless.
In this thread where a small shock is felt it is very possible that the current is coming from the other side of the lake and this would be especially true if there is a high measure of contaminants such as lead, mercury, iron, ect… is present in the water.
Somewhere current is traveling through earth to the metal dock looking for a path back to its source. What Randy purposes is to disconnect the equipment grounding conductor breaking this path thus the loss of the shock. What he has now done is remove the path for any fault current from the branch circuit that is supplying that dock a low resistive path to clear the fault thereby causing the water and earth to conduct the faulted current and anyone in the water and touching the energized dock to die instantly. If the shock don’t get them they drown.

In order to prevent someone getting shocked by these stray voltages an equipotential bonding grid can be installed to make all potential equal and no shock.
Watch this short video for a good example of equipotential planes
http://www.youtube.com/watch?v=LIjC7DjoVe8



I hope this help you better understand but should you have more questions please ask.

[LOTW]

JW, thank you for your thoughtful reply. i was aware that an open neutral could cause this condition. My high school shop teacher 40 or so years ago called the same a "break in the continuity" and in my simple terms I think of it as simply a "short." But, if it is a neighbor's system that is causing problems, how can the problem be fixed at my dock? And does the problem exist to the same level if the dock is a permanent wooden dock built on piers?

[jwelectric]

This is a problem the world over not just at lakes. My neighbor was having problems with his swimming pool until the utility found the problem almost a half mile away. It took two years to get action from them. There are several dairy farms around me which have had problems with stray voltages.

As bad as it sounds on this type of discussion board the first approach to the problem especially around lakes is to start prosecuting those making electrical installations that are not code compliant.
When people start bypassing the safety measures put in place by our building codes the problem is magnified. Some good examples of this type of installation are demonstrated throughout this thread.

The NEC is a minimum safety standard and to do anything less is an unsafe installation.

90.1 Purpose.
(A) Practical Safeguarding. The purpose of this Code is the practical safeguarding of persons and property from hazards arising from the use of electricity.
(B) Adequacy. This Code contains provisions that are considered necessary for safety. Compliance therewith and proper maintenance results in an installation that is essentially free from hazard but not necessarily efficient, convenient, or adequate for good service or future expansion of electrical use.

As you can see the entire code is a safety code that is in place to protect the user of electricity from the hazards of electrical current. When someone starts making short cuts it is my opinion that they should be charged in criminal court and put in jail.

The only way to make these piers and docks totally shock free is to install equipotential bonding grids in and around them. When those untrained people start doing things such as stated in this thread the stray currents are multiplied and more people are hurt.

As I have stated on this site many times, electricity is not for the untrained. There is enough current in one 15 amp circuit to kill 15 people at the very same instant and never trip the breaker.

[jimbo]

Pretty good discussion here from "rock of the marne". The whole topic of ground is electricities version of vents in plumbing....not everyone can see the whole picture.

I have often read about the problem around barns...I assume it has something to do with the earth being very soaked with urine?? But where does the current come from? Is it a defect in the power system itself, or leakage from electircal devices in the barn?

[LLigetfa]

The problem might be poorly balanced long service feeds. Randy tried to explain it but it was either lost in translation or JW dismissed it. I live in farm country where long driveways are the norm. In most cases, the transformer (can) would be located close to the buildings rather that out on the road to reduce the length of the 240 Volt run but some of the homes on our road share a can on the road and have long feeds instead. The utility here has a rule that states two adjacent poles cannot each have a can. There was just one pole on my frontage and the adjacent pole further away already had a can which was shared by two neighbors. I worked out a plan to relocate the next pole over so that it was on the corner of my lot so that I could put a can on it and feed underground to my home keeping the length reasonable. To put the can any closer would have cost me 3 additional poles and guys.

I'm thinking JW will be quick to point out that the centre tap neutral on a 240V service carries very little current and in a well balanced panel I would agree but panels are not always well balanced and so the more current carried on the neutral, the more voltage drop potential exists, depending of course on conductor size.

[Randyj]

JW/Mike. I want to thank you for all the challenges. It does help a heck of a lot in my continuing education. I've been doing all kinds of maintenance for about as long, if not longer, than you've been involved in your field. I once went to apply for a job in maintenance at a sports complex. They wanted to hire someone to do all the repairs on plumbing, electrical, vehicles, and be a locksmith too... for just above minimum wage. You see, they wanted someone who needed to be well educated and qualified in all these fields but wanted to pay them less than a person makes in any one of these areas. A good and qualified maintenance man is worth as much as any electrician or plumber or other skilled laborer because he knows at what point he needs to call in a licensed professional. As for any involvement I have in electrical repairs there is nothing I do that a home owner DIY'er can not do himself. It is certainly not my intention to circumvent the law or do non-code compliant repairs. For several years I worked for the largest custom sign building company in the USA, worked my way up to plant manager. I was privy to every aspect of that company and responsible for it too. The reason I left the company had to do with the way customers we serviced which I did not feel was right. I was very good for the customers, not for the company. Everything we did had to be compliant with UL standards to meet any code in the USA as we were wholesale manufacturers, built signs for other sign companies nationwide and shipped them all over the USA and Canada and have sent them to the Virgin Islands and Alaska. Still, UL would come in and change their requirements frequently. One time they would come in and say fluorescent transformers had to be in the top of a sign cabinet (to keep them out of wet raceways) and all wires enclosed in a raceway. The next time they would come back in and say that because of the weight of the transformer they presented the danger of falling from the top of the sign cabinet. So, they changed back to their previous requirement that the raceways in the bottom of the sign cabinet had to have drain holes in them and the transformers were to be placed in the bottom. Now, if you go to do maintenance on one of those signs you'll find dead bugs or dirt dauber nests plugging those drain holes. Kinda like every time someone new comes in they find a way to make changes and it is hard to follow the logic of the person(s) making those changes. I do definitely agree with the absolute necessity of making any electrical connection safe PERIOD.
As to the metal dock grounding issue which I hope, in layman's understanding, we can find common ground. It appears to me that what the linemen and electricians mentioned in that link are describing is that the earth ground to neutral do remain connected at it's source (the switch box panel). Certain terms and phrases confuse those not familiar with technical jargon, "clearing fault", is one of them. What it appears to me that the method those guys are using is doing is establishing a better and foolproof path for faulty current to return to earth. On a metal boat dock there is already a path to ground but it is no more reliable than a ground through a trailer hitch. The ground rod and bonding at pivots/hinges insures this path. What I want to argue so that we understand is the item of earth grounding... that green wire to receptacle grounds. If what you are saying is true then the shortest path to earth ground would be directly to the dock to a ground rod as described and not hundreds of feet away at the switch panel. If a hot wire energized the dock the circuit does not remain in the hot wire to neutral. It establishes a circuit from hot wire to dock to ground. I would think that following what you are saying the ground rod connected dock should be bonded to neutral at the dock switch box if one exists or at the junction box if that's all they have. What I see from the what you are describing is the very thing that results in these stray voltages that cause the low voltage "tickles" people complain about. This is repetitive but what I see in the methods the "guys at the lake" are doing is equalizing the potential from dock to earth and water which in effect becomes a totally different circuit when or if that dock is energized. I'll re-read everything you've posted to try to clear any fault in my brain. The one thing I do want to get out of this discussion is to be able to tell people why or why not their grounding method is wrong if I happen to see it while doing any kind of maintenance work at their property. The other thing is to make absolutely sure their dock installation is safe regardless of who their electrician or dock installer was. Many of these docks are built and wired in a manufacturing plant then it is up to the property owner to hook up the electrical supply. Many are going to buy UGF which they think is big enough to run a few lights and a battery charger for their bass boat. Not many are going to calculate loads then go out and buy wire and breakers which are mathematically correct. It is not just on this lake but all up and down the river below the dam and at every lake and river I've ever been to. The only place I've seen metal floating docks is on lakes such as this which has an extreme fluctuation of lake levels. In the couple of weeks we have seen the lake level fluctuate about 9 feet. The allowable lake level fluctuation is 29 ft.

[Randyj]

Several weeks ago I posted a question regarding wiring my boathouse with a single circuit and received much helpful advice. I am interested in this topic, know little about electricity, and have gotten more worried as this thread has increased. Forgive my ignorance, but I have a simple question: How can one receive a "tickle" or some other shock without there being worn insulation or some other access to the current? I understand how dropping an electrical tool into water produces a shock, but how can a person be otherwise "tickled" on a dock unless there is an exposed wire or other "short" which would allow the electricity to reach the dock? And to reduce the risk should a person use both an GFI outlet and a GFI breaker, or just the breaker?

LOTW... I started out in this thread to ask the same question. I wanted to know if someone had different thoughts or theories on this than what my understanding and knowledge is. Tho, I very poorly wrote the O.P. To clarify and verify what I thought to be true I asked several people including a licensed contractor and inspector. Funny thing is that not one of them quoted me NEC regulations... which just adds a heck of a lot more information to have to process in my mind. What I got out of these discussions is that a GFI outlet only gives GFI protection at that outlet wheras a GFI breaker gives GFI protection to everything on the circuit it feeds. Using GFI outlets simplifies locating the fault because only that point of the circuit is affected. If you use a GFI breaker you don't know specifically at what point the fault occurred without analyzing everything beyond that breaker. The good thing about a GFI breaker is that it gives the complete circuit GFI protection. So, a GFI breaker can be used and if you want to add GFI outlets you can do that also... either or both... but it is somewhat self-defeating and duplicating. I would think that if the outlet trips fast enough the breaker wouldn't trip. But, if the breaker sensed the difference in the circuit then it would also trip. One thing I am still unclear or perplexed about is why when some people return to the lake house periodically every GFI outlet on their dock will be tripped. I have one regular customer where every time I've been to his dock to do repairs such as welding or painting the GFI outlet to his boat lift is tripped. I suspect this to be due to lightning or some stray voltage. As for your other post, at no time should a neutral wire be cut/disconnected. The earth ground should never be substituted for the neutral in a circuit. This is something I've discovered several times when I found an outlet having at or about 64 volts. When I see that I know what the likely problem is... some idiot swapped the neutral wire with the ground wire. Lights still worked. Not sure if I'll get bashed for this or not but the resistance is part of the reason a phase shift caused by time delays of the return of electrons to their source comes into play here but of course I don't want to go there.. far too geeky to get into sine waves, crests and troughs.
I think JW explained it but the way a GFI works has nothing to do with earth ground but functions by comparing the voltage/current between the hot wire and neutral wire. It takes an extremely small difference in this current to trip a GFI. In effect, for the current to stay on in a GFI the alternating current must be exactly equal in both wires. In an alternating current the voltage is constantly changing so this change has to be equal at the same point in time.

[jwelectric]

Randy,

UL does not mandate how a sign is to be built. The designers of the sign summit their plans to UL and then UL either approves the plan or sends it back for future evaluation by the designer. The location of the ballast was not due to UL mandating where it was to be installed but instead it was mandated by the person that summited the plan to UL.

You continue to make this erroneous comment;

What it appears to me that the method those guys are using is doing is establishing a better and foolproof path for faulty current to return to earth.

Once again no current returns to earth but current returns to the transformer from which it came. The only reasons we connect to earth are as follows;
1- limit the voltage imposed by lightning,
2- line surges,
3- unintentional contact with higher-voltage lines
4- stabilize the voltage to earth during normal operation.
The first one is pretty simple to understand as about everyone has seen the result of a lightning strike at some point in their life and most understand that lightning is an event between earth and clouds. Our wiring is somewhere in between the two and needs to be connected to one or the other so it can get rid of the current as soon as possible. I suppose driving a rod in the cloud would be just as good as driving one in earth but it might be a little harder to do.
Second could be due to lightning surging the grid or even a primary shorting to the secondary from an upstream transformer
Third is easy to understand if one would only take the time to look at a utility pole. The higher the voltage of the conductors the higher up the pole they are installed. In the event of high winds or ice the higher voltage lines come down on the lower voltage lines.
Forth is so simple most can’t conceive its meaning. When I take a voltage reading I am reading what the voltage potential is above earth.
In this same code section we are told that earth can’t be used as a conductor.

You seem to be sold on the idea that current is somehow going to run into earth and dissipate down there somehow. This just is not true. If one electron leaves the transformer going down a wire then one electron MUST return to that transformer and not run into earth.
When we do electrical work on our cars and trucks such as the trailer hitch you mentioned we make the comment that we have to ground the light before it will burn. Is there some connection from that car or truck to earth? Then it is not grounded as we are talking about in the wiring of our homes. When we are talking about grounding in our homes we are talking about connections to earth but when we talk about grounding in our cars and trucks we are talking about a connection to the negative side of the battery and not a connection to earth.

At our service equipment we join (main bond) our equipment grounding conductors, our grounding electrode conductors (the ground rod), the service enclosure (the gray metal box that has a door), and the grounded (neutral) conductor together with what is called the “main bonding jumper” It is this bonding that give fault current a path back to the transformer.
In the event of a ground fault at the metal dock, the hot wire touches the metal dock, the current is carried back to the main bond at the service and then back to the transformer just like when we touch the hot conductor to the dashboard of our car or truck. This causes the fuse or breaker to open clearing the fault. What happens when we touch the hot conductor to earth from our car or truck, nothing but when she hits that dashboard sparks fly. This is because this fault current is returning to its source through the frame of the car or truck.
When we connect these metal docks to a ground rod at the dock and disconnect the equipment grounding conductor we now have to carry this fault current down the ground rod through earth to the service ground rod before the fuse or breaker will open. Unless the ground rod at the dock is within two or three inches of the ground rod at the service then the resistance of earth is going to be too great for the current to overcome and the fuse or breaker will not open thus putting anyone who touches the metal dock in grave danger.

Two misconceptions you have,
1- that current is trying to go into earth or ground if you please
2- that current will take the path of least resistance
Both of these statements are false and very untrue.

[jwelectric]

A GFCI device will open when there is 5 milliamps (.005) difference between the hot and the grounded (neutral) conductor. A GFCI device will operate with or without an equipment grounding conductor.

Being the only time an equipment grounding conductor carries current is in the event of a fault to ground the EGC plays no role in the .005 (5 milliamp) of the trip threshold of the device.

A couple of things to remember about GFCI devices,
One they don’t replace the equipment grounding conductor and a circuit that is protected by a GFCI device that does not have an equipment grounding conductor is just as dangerous as a circuit without equipment grounding conductor and no GFCI device
Second and the one most will find hard to believe. A GFCI device will not prevent you from being electrocuted. Should you come between the hot and the grounded neutral of the circuit the GFCI device will see you as any other load and it will not trip. At 100 milliamps (.1 amp) will in is most cases be fatal. This means that using the trip curve of an inverse time circuit breaker or 5 times its rating a 15 amp breaker could kill 750 people at the same second and still not trip.

If it only takes .005 amps (5 milliamps) to open a GFCI device then one exposed to the weather would most certainly trip.

It is perfectly alright to put a GFCI breaker in the panel and then install a GFCI receptacle at each location on the circuit that the breaker is protecting even if the GFCI receptacles are daisy chained.

.

[Randyj]

Honestly, I think we are arguing the same point(s) from different sides of the fence. Fact is that the metal dock is already connected to earth ground. I think that what might need to be clarified is whether that metal enclosure exists on these docks as many only have a wire running to a junction box (no breakers on the dock at all) and in most cases the branch circuits are in either PVC or metal conduit with combinations of flex and all manner of metal fittings. IMO, the dock would need to be bonded to the ground rod so that current always will escape to the earth before escaping through a swimmer... and yes, I do agree that the swimmer would in any case present a resistive path and therefore be subject to a portion of any voltage present. Again, I refer to the analogy of water in a pipe... if it leaks only a portion of the water takes the path of least resistance. The rest of the water continues throught the pipe. Same with electricity. That's how a bleeder resistor circuit drains off electrons. So... are you saying that to balance the "earth ground" then the "earth grounding" from that box with the door on it should be connected(bonded) to the dock AND a ground rod at the walkway to the dock? Would this not create an imbalance of potential between the dock and earth?----> low voltage tickle/ants in pants?
.... gotta go do some honey do's... .will look for your reply tonight.

[jwelectric]

IMO, the dock would need to be bonded to the ground rod so that current always will escape to the earth before escaping through a swimmer...

Just what part of the current is not going to escape to earth do you have a hard time understanding?
The current is not and I repeat is not and just one more time is not going to earth.

and yes, I do agree that the swimmer would in any case present a resistive path and therefore be subject to a portion of any voltage present. Again, I refer to the analogy of water in a pipe... if it leaks only a portion of the water takes the path of least resistance. The rest of the water continues throught the pipe. Same with electricity.

NO!!!!!!!!! THIS IS NOT HOW ELECTRICITY WORKS. PART OF THE CURRENT CAN NOT LEAK LIKE A WATER PIPE!!!!!!!!!!!

That's how a bleeder resistor circuit drains off electrons.

A bleeder resistor does not leak current to earth. It divides the voltage through a series circuit and earth plays no role in the dividing.

So... are you saying that to balance the "earth ground" then the "earth grounding" from that box with the door on it should be connected(bonded) to the dock AND a ground rod at the walkway to the steps?

NO!!!!!!!!!!!!!!!!!!!!!!!!! The ground rods does not balance anything. The earth ground does not balance anything. The rods plays no role what so ever in how the current responds to the circuit. You could drive 10,000 rods and it would solve nothing.

Would this not create an imbalance of potential between the dock and earth?----> low voltage tickle/ants in pants?

NO!!!!!!!!!!!!!!!! The ground rods would not cause any imbalance in anything except your mind.
The dock would be just as safe is there was never a rod driven anywhere unless the dock is struck by lightning in which case the concrete holding the dock in place would be just as good or even better than the driven rod.

Just what role do you think the ground rod plays in an electrical circuit? Please answer this one simple question