bonding/grounding copper pipes

[jwelectric]

Jim Port has already tried the claim of indifference but his was more nearly grammatically correct. It's "I couldn't care less. . ".

I couldn’t care less would be saying I could not care less and what is said was that I could care less. One means that I could not care less and the other means that I could care less. So add me to your ignore list and watch me care even less then than I do now.

I don't believe him or you.

This is the basis for ignorance. Until you learn to believe those in the know you will continue to walk around in the dark thinking you know something you don’t.
Your attitude reminds me of something that Columnist Sidney Harris said, “There is nothing more dangerous than a person with a good mind who begins to reason, logically and coolly, but from insufficient premises; for his answers will always be valid, justified, rational and WRONG.

I bother both of you for reasons that are in both of you. It behooves you to find out those reasons. You'll be a better person for it.

You do not bother me at all. You are just wrong most of the time and refuse to listen to reasoning which speaks more about you than words could ever cover.

I don't know if my profile has a low/high/average number of looksees or what the ratio of posts to looksees means.
I guess I'm flattered and surprised about how many people are curious about me.

Well it is good that you take it as flattery but I think you may be mistaken

It's useless to post my credentials so I guess I'll have to be judged by my posts on this forum. There are worse things that could happen, and have happened, to me.

I suppose if one does not have any credentials then there is none to be posted.

Speaking of ratios, you can probably improve your systolic to diastolic ratio by putting me on your ignore list. Yeah! Nobody can say I'm not lookin' out forya'.

I take Losartan every morning so therefore I have no blood pressure problems. Last check this morning was 109/60 which is really good. The old blood sugar was 92 which is even better. I also burned 800 calories today at the gym which keeps everything in check.

[jwelectric]

As far as I know I left on my own, along with leaving many other sites. With one site that I left I requested that all my posts be removed but they constructively refused.
On one site I was banned twice. The complaint was not the same as yours.

And is without a doubt the reason you left the others, “The complaint”

Unfortunately, a lot of questions do not have simple yes/no answers. If you ask a question about things that concern a grown-up you should expect a grown-up answer.

And we are still looking for this grown up answer

I hope you're wrong about people not wanting to know the rationale behind my answer. I think it makes my posts more credible.

I have to yet to see a post you have made that has any credit due it

Both people on my ignore list are electricians. With few exceptions they don't seem to know theory - OK - but they don't seem to want to know it.

Well ain’t that a mouth full!
Check out this site
http://www.randolph.edu/continuinged...electrical.php
I have been teaching these classes for over 10 years now as well as taught Curriculum classes for more than 7 years. Yes these are college transfer classes.

Don't you guys ever check your work, using electrical means to check the integrity of the connections?
Don't you wonder "Why is this symptom happening?
Does your troubleshooting strategy consist of more than "Checking the neutral?"

Yes and I also teach trouble shooting in three of my classes as well as electrical safety in all my classes

The NEC is not a bible, and it is certainly not my bible.
Furthermore, I doubt there is anyone on any Code Panel that advocates for the consumer and is knowledgeable enough, or cares to, to balance potential risk with cost and benefit.
What I see is conflict of interest. For the sake of the uninformed consumer, I hope I'm wrong.

You have now posted one item that is correct. The NEC is not a bible but in jurisdictions that have adopted the NEC it becomes LAW that must be adhered to.

I try to structure my posts as an abstract followed by an increasingly detailed explanation. The reader can bail out anytime he/she wants to. They are also free to ask questions, and some do.

If even one thing I write helps the OP in some way, good. If I help he or she look at a problem from a different angle, good. If I come up with other options, good.

The ball is in your court.

once again I quote

“There is nothing more dangerous than a person with a good mind who begins to reason, logically and coolly, but from insufficient premises; for his answers will always be valid, justified, rational—and wrong.” Sidney Harris, Columnist

The simple truth is you know nothing or little of what you are talking about.

[Terry]

I was repiping a home with a homeowner years ago. He would mention that he had two doctor degrees, and I had none. Well thank you for that.
Two, geez, my father only had one from the University of Washington in Law and my brother James Packard Love didn't even pick up his doctorate from Princeton. He's been getting by on a measly Masters from Harvard all these years. But yes, here I am with my "High School" diploma, trying to show this guy the ropes on plumbing, trying to keep him out of trouble.
I was trying to explain the compression fitting thing to him, copper stub outs, cut them off after the cabinets are set and then slide on the compression stops, and cinch them up. But now, he was telling me that then he couldn't ever replace them. So I said, say what? We replace compression stops all week long using a sleeve puller. But he with the many doctor degrees in plumbing, no wait, not in plumbing, something far and away from plumbing. He told me that the many doctor degrees meant that his brain could out brain mine. So I just laughed it off, and let the big brain go right on ahead with his blunder.
A week later he calls up telling me he's burning up his cabinets, making them all black and nasty with the torch. And I'm like yeah...what's your point?
It doesn't take a rocket scientist to know that a torch in an close space will use up the oxygen and start flaring in your face. I love the smell of someone else's eyebrows melting. Don't you?
So I say, Are you getting why I like using compression yet?

We're friends now. He is smart about computers.

[jimbo]

I think our old buddy Sylvan has morphed into an electrician~~!!!

[nukeman]

jw and Thatguy are borth correct in their own way. In terms of voltage, the key is in reference to what? Voltage is the electrical potential between two points. If you want to talk about the voltage making a current through the body, you need to know:

1. Resistance of the body between the points of contact. This can vary greatly between people as well as what you are wearing (gloves, shoes, etc.)

2. The voltage difference between the point of contact. For intance, you could hang a metal cage in the air, stand inside, and charge the thing to 700kV. Will it kill you? Nope. Will you feel a shock? Not likely. Everything in that cage is at 700kV, so the voltage potential across your body is 0v. Some might thing that different parts of the cage might be at different voltages due to resistance of the metal, but this is not the case. You only get volatge drop if current is flowing. If the cage is isolated, then everything will be at the same voltage. See "Faraday Cage".



Using current to define damage to the human body is a better correlation than voltage. However, from a safety point of view, voltage is sometimes more useful. Voltage of a circuit is known. The current is not. The circuit might be able to flow 100A, but that doesn't mean that it will flow 100A through your body. By estimating body resistance and assume that the full potential is across the person's body, one can determine the risk to that voltage. For instance, I can touch both sides of a car battery that can supply a couple hundread amps when starting a car and feel nothing. If I grab onto something that is at 40kV and can only supply, 1 amp, I am probably dead.

Terry: I have a doctorate, and I hope that I have common sense, but I know there are a lot of smart people out there that do not have common sense. It is amazing how far they get without it. I don't get it. I also know a lot of smart people who have no practical knowledge. Can't even change the oil in their car or do simple fixes around the house.

OP: If it were my house, I would bond the copper. It wouldn't work as an electrode, but would cause the breaker to trip if the piping were to become energized due to faulty wiring.

[ballvalve]

MOST of the "smart" people out there with numerous degrees have no common sense indeed. Some that do have no ambition to get dirty.

Some of the HUGE paying jobs that these guys get with some institution or university have goals or results that are so obtuse and useless that it boggles the mind. Even the titles of their "work" are indecipherable. Our tax dollars at work again.

I have contacted a few high voltage lines with an excavator, with no ill results except some wild sparks. The window sticker says to stay put and dont move if you cant get off the wire. If for another reason you must evacuate, they say that the longest jump you can manage out the cab is the poor second choice.

[jwelectric]

jw and Thatguy are borth correct in their own way. In terms of voltage, the key is in reference to what? Voltage is the electrical potential between two points. If you want to talk about the voltage making a current through the body, you need to know:

1. Resistance of the body between the points of contact. This can vary greatly between people as well as what you are wearing (gloves, shoes, etc.)

2. The voltage difference between the point of contact. For intance, you could hang a metal cage in the air, stand inside, and charge the thing to 700kV. Will it kill you? Nope. Will you feel a shock? Not likely. Everything in that cage is at 700kV, so the voltage potential across your body is 0v. Some might thing that different parts of the cage might be at different voltages due to resistance of the metal, but this is not the case. You only get volatge drop if current is flowing. If the cage is isolated, then everything will be at the same voltage. See "Faraday Cage".



Using current to define damage to the human body is a better correlation than voltage. However, from a safety point of view, voltage is sometimes more useful. Voltage of a circuit is known. The current is not. The circuit might be able to flow 100A, but that doesn't mean that it will flow 100A through your body. By estimating body resistance and assume that the full potential is across the person's body, one can determine the risk to that voltage. For instance, I can touch both sides of a car battery that can supply a couple hundread amps when starting a car and feel nothing. If I grab onto something that is at 40kV and can only supply, 1 amp, I am probably dead.

Terry: I have a doctorate, and I hope that I have common sense, but I know there are a lot of smart people out there that do not have common sense. It is amazing how far they get without it. I don't get it. I also know a lot of smart people who have no practical knowledge. Can't even change the oil in their car or do simple fixes around the house.

OP: If it were my house, I would bond the copper. It wouldn't work as an electrode, but would cause the breaker to trip if the piping were to become energized due to faulty wiring.

Nuke man

You are almost correct and I think you know your mistake.
There are basically four components to Ohm’ S Law; voltage the force of pressure, current the amount of electrons passing a point, resistance or the opposition to the flow of these electrons (current), and wattage or the amount of work being done, or W=IXE and E=IXR.

Current or the movement of electrons is what is moving through any conductor be it a wire or a human. Voltage is the pressure that is pushing that current through a conductor be it a wire or a human. The amount of damage done in an electrical shock is the power or wattage produced.

In order for this current to flow through this conductor be it wire or human three things are required. 1- a power source 2- a path 3- a load. The path can also be the load. We don’t want to be either.

To the best of my knowledge the lowest voltage that has ever caused death was 50 volts. Using Ohm’s law at this voltage a person would have to have a body resistance of around 500 ohms. This would mean that the current has entered the blood steam or the person was coated with some sort of conductive something.
The average male will have a body resistance of between 3 and 5 thousand ohms stand completely dry. This means that at 120 volts a current of 24 and 40 milliamps will travel through the body. This would be well above the let-go-threshold .

As to bonding the short pieces of metal pipe in the dwelling and one becoming energized I will ask where this power source is going to come from? If there is no source of electricity then why bond?
If you are going to bond one piece are you going to bond all of them or are we going to make the pieces of metal pipe electrically continuous?

I would first find out where the source is coming from. If I cannot find a source then I am not going to bond.

[nukeman]

The voltage difference across the body and the resistance of the body will determine the current. Power is power. It is part of Ohm's law and relates other parameters:

W=I^2R, W=V^2/R, W=IxV, etc.

In this case, we don't really care about the power. Primary concern is the current. Power is only useful in this case if you wanted to figure out how quickly you can raise the person's temperature. It is all related, though. If you want to say xx mA kills or does damage to a person, you have to make assumptions on the resistance of the person if you want to relate to power or to a voltage. You might also argue duration of the shock (energy=Watts x time). Bump 240V with the back of your hand and get a quick zap. Grab onto the same line and not let go is a whole other issue. The other sticky point is that it really only depends on voltage across your body if you are going to calculate power or current. For intance, you might get hit with a fairly high voltage, but there is a large voltage drop across the soles of your shoes. You wouldn't just use the "normal" body resistance or the full voltage to calculate the damage to the person's body as a lot of that energy is going into trying to melt the bottom of your shoes. You instead would look at the voltage difference between the tip of your fingers (or whatever) and the bottom of your foot. That is the real voltage (and related current/power) that your body is seeing.

For bonding, I was taking the whole house to be copper, but plastic coming in. If you have access (like a basement), it is so easy to do, you might as well. For power source, you may or may not know where all your NM cable is in relation to your plumbing. They could touch at some point. You could have a rodent chew through the insulation or you could have a careless plumber. What I mean by the plumber part, I opened up a ceiling during some reno work and found that the plumber torched the hell out of the NM wire that was running near a coupler to feed the shower. The probablilty of the piping becoming energized is small, but if it is not difficult to bond, I would do it just for added protection. In my case, the cooked wire wasn't touching the plumbing (and the plumbing was bonded anyway), but you can see how it could have been energized if touchng and not bonded. If all of the plumbing was behind walls and could not easily be accessed or if it was bits and pieces of copper mixed with plastic, then I wouldn't bond it. My point is that you don't usually know who has done what in the house before you, so you often don't know what is going on behind those walls.

My opinion is that if something can reasonably be done and can have some possible benefit, then I am going to do it and do it right. Some things that I did, but didn't have to:

- WH wasn't grounded when we moved in. The sellers had a handyman run a separate ground (the wire was 10/2 w/o ground). Since I had everything open, I replaced this with 10/2 w/ ground
- Replaced 3-wire to dryer with 4-wire.
- Added ground rod in addition to the existing water system electrode.
- Re-ran the bonding to the water system to within 5' of where it comes into the house instead of having it bonded somewhere in the middle

These are just some examples of things that probably won't make a difference in any real way, but it was easy and cheap. Why not bring things up to code if you can?

If you are paying a pro to come in and do it, then you might be better off just leaving things unless your inspector want it done due to the reno work that you are doing.

[jwelectric]

Primary concern is the current.

And this is the exact same thing I was saying to thatguy. Is thatguy really a woman??

In order for someone to even be able to feel 3 volts AC the total of the series resistance of the human body his shoes and whatever he was standing on would have to be below 200 ohms. In order for it to kill the total resistance would need to be around 30 ohms.
Now we both know this just aint gonna happen at no 3 volts AC

[nukeman]

I agree with you. However, I think that thatguy is saying the same thing in a different way. He is saying that you can look at voltage. You can use the voltage and the person's resistance to figure current. As I mentioned before, it is difficult to really know what the real current could be because it depends on the resistance of the person (this can vary greatly from person-to-person and that doesn't even include other variables such as shoes/clothing). Because of this, it is often helpful to look at voltage to determine how dangerous a circuit might be to a person. We all know that you can grab onto 12v all day and it won't do a thing. If you are working on a 480v AC circuit, then you have to be very careful. There is some threshold voltage between what is safe and what is somewhat dangerous. This depends on the person. In terms of common voltages, one might say 110v+ you better play it safe. Under say 50v, you are likely safe. Between 50v and 110v, you are also probably safe, but probably should start thinking about what you are doing.

Another factor is the frequency. Normally, one (in the US anyway) will only run across 60Hz power. However, higher frequencies behave differently (both in how the current flows and how it interacts with the person's heart/muscles/nervous system. In fact, most higher frequencies are safer than the 60Hz that is commonly used.

Here's an example. In the picture that I posted with the guy in the cage, that spark is coming from a Tesla coil (I am a bit jealous that I don't have one that big. ). The way this works is it uses an inductor, a capacitor, and a spark gap on the primary side (along with a high voltage transformer). This primary side is connected to a coil with lots of windings. The primary side is adjusted and tuned to the secondary side. This magnifies the voltage a great deal. I built a small Tesla coil just out of HS. Mine uses a neon sign transformer (6kV) and a bunch of simple things. The output is something like 250kV (it can throw sparks a good 12" in air). In fact, I could add a sphere or a torus and get even bigger sparks. Although the voltage is high, the frequency is also high (~22kHz). I can take sparks to my wrist without any other protection and get nothing more than a tingle. The larger Tesla coils (like in the pic) will use a small Tesla coil like mine on the primary side. They then magnify this and can get several million volts or more.

Fun stuff.

http://en.wikipedia.org/wiki/Tesla_coil

[jwelectric]

I agree with you. However, I think that thatguy is saying the same thing in a different way. He is saying that you can look at voltage.

But what he said is simply wrong.

1. Originally Posted by Thatguy
I would do this for a reasonable price. With wet skin you are very vulnerable to electrocution, but you have to check that grounding actually gives you 1 VAC or less. For some people some of the time 2 VAC would be above the let-go threshold.

There is no such thing as a voltage let-go-threshold and it sure isn’t 2 volts. This is incorrect information plain and simple.
The let-go-threshold is measured in current and in current alone. Voltage plays no role what so ever in the let-go-threshold.

As an engineer you should know that voltage does not move nor flow. Electrons move or flow and it is the flow of electrons through the human body that is felt, hurts, and does damage. The movement of electrons is measured as current or amps. This is a law of physics that cannot be changed.

Now we can play around with voltage all day long but the fact still remains the same, it is current that does damage not voltage. It is current that flows not voltage and it wouldn’t matter what the resistance was. It doesn’t matter if it is parallel or series. It is still the movement of electrons that is the flow of electrical energy not the pressure pushing this flow. Simple electrical theory taught in the first semester of class.

[nukeman]

Okay. It looks like that post was deleted and I didn't see it. That is why we aren't making a connection.

I understand 100% that current is what causes damage and the relationship between current, voltage etc. Yes, you can have a voltage and no current. This is why I said that when you are talking about voltage in the case, you have to talk about the voltage difference across the person and not a voltage referenced to something else. If there is a voltage difference, there will be a current (unless the resistance = infinity)...Ohm's Law.

My point is that it is hard to identify a circuit that might harm you based on the current that could flow through your body. If the average person is working around a 220v circuit. Say they happen to know (or maybe they don't know) if they come into contact with that voltage, how much current will flow through their body and what the damage will be (tingle, knock you on your rear, death, etc.). Because of this, it is often helpful to say the average person = ***x Ohms and the amount of current to cause major damage = yy mA. With these, you can use Ohm's Law to multiply together to get a voltage that would cause this damage. It is not perfect since there are many factors, but could be a good measure of risk.

It is just a way to measure risk (12v car battery vs. 700kV transmission line). The voltage drives the current. 12V across you is nothing. Try that with the 700kV transmission line and you'll ruin your day.

Thatguy is also talking about probability. The idea is that you gather all of your cases (or as many as possible) of people who have got a shock of some kind. You might bin them into different categories (feel, hurt, death, etc.). If you can figure out how much current went through their body, you can seperate these people into "bins". For instance, you might find that 25% of the people sampled were in extreme pain with 65-75 mA. You might have another group that this current caused death. Anyway, you come up with a distribution. The current ranges that you normally see for feel, hurt, death, etc. are in the peak of this distribution. However, there will be people who fall outside of this range. As you go away from the peak, the probability of finding a person where that current does that damage drops off. It depends on the type of the distribution, but many extend to infinity (in both directions) with the probability dropping to zero. I think that Thatguy is talking about the very few people that are outside of the normal range. There might be a handful of people in the world that a current that would cuase a mild shock in "normal" people might cause death in their case. It also goes the other way and there can be a group of people that can take the current better than most people. However, most people (say 95%) will be in the "normal" range for current vs. damage.

[reed50]

I appreciate everyone's responses. Just so I understand the reasons why some recommend bonding the pipes: it's because a stray wire may come in contact with the pipe. Does it have anything to do with the things that use water and electricity (water heater, dishwasher, washing machine). I guess what I'm trying to ask is it in case of someone not wiring one of these things correctly, or am I totally off base on understanding this? Once again, thank you to everyone for their patience (and my stupid questions).

[jwelectric]

Okay. It looks like that post was deleted and I didn't see it. That is why we aren't making a connection.

We have been making a total connection. Just as you have explained in the post i have quoted you from you maintain throughout that post that the current that travels trhough the body not the voltage.

Thatguy made the statement that 2 volts might be above the let-go-threshold and here he is completly wrong. Herein lies all this debate.

[jwelectric]

I appreciate everyone's responses. Just so I understand the reasons why some recommend bonding the pipes: it's because a stray wire may come in contact with the pipe. Does it have anything to do with the things that use water and electricity (water heater, dishwasher, washing machine). I guess what I'm trying to ask is it in case of someone not wiring one of these things correctly, or am I totally off base on understanding this? Once again, thank you to everyone for their patience (and my stupid questions).

There is no code requirement to bond anything concerning these pipes. Your equipment such as those appliances you have listed here will have an equipment grounding conductor that bonds any metal pipes connect to them so nothing else is needed.
Don't let anyone try to scare you into doing anything different either.