My trailer got fried!

[uncle_bob]

Hi

I guess we'll go back around this again ...

Ground is a wire in a plug. The name of the wire in the plug does not change depending on where the wire goes. It still is called the ground wire. Often it is green sometimes it is green and yellow. The name of the wire does not change when the color of the wire changes.

The ground wire is there to make you safe. If current flows in the ground wire, that's a bad thing. It's flowing to *keep* the current from hitting you. That's why it's there. You could easily call it the safety wire. For historical reasons we call it ground.

Neutral is a different wire in the plug. That wire is *supposed* to carry current. The voltage on that wire should not be very high. That's how we get the name neutral. You could also call it zero volts or you could call it return. Since calling it three different things is a bit confusing, we call it neutral. Normally it's a white wire. Again, if the color changes, the name does not change. It's the function that gives it the name.

Hot (and there may be more than one) is another wire in the plug. It's purpose is to supply voltage relative to the other hot leads and the neutral. If you have voltage, you can hook up a load and get current. You could call it supply or main or Bob. We call it hot. Usually it is a black or red wire.

Ok, so much for naming of wires. You will notice that the planet did not in any way get involved in the names of the wires. It's not part of the picture. Three wires and three names. One name for each wire.

Now, if any of these wires are not connected, that's a problem.

If the hot is not connected, you don't get voltage. No voltage means no current through the load. Nothing good happens. The circuit is dead. Throw the switch to the "ON" position and maybe you will hook up the hot wire.

If the neutral is not connected the current has no place to go back to the source. The load is "hot" in terms of voltage. There is no current. No current = nothing happens. Since there *is* voltage, don't poke your fingers in to see what's going on.

If the ground wire (remember it's just the name of a wire) is not connected, there is no safety return. Current (like from that open neutral) can leak to the housing of your gizmo. It has no place to go ( no neutral no ground) it's next best bet is going through you. This is *not* what you want to have happen.

In order for things to be set up *safely* the ground wire needs to be hooked to the neutral wire at the source of power. Hooking it to planet Earth is optional. Hooking it to neutral at the source is not. It's there to protect you. If you don't hook it up it will not do so.

If indeed this does not make sense to you, consult an RV electrician and have them check things out for you.

As with any safety system, you don't die the instant it goes out of whack. People survive all sorts of dangerous situations. That is *not* a reason to live dangerously.

Bob

[xrvr]

So should we start a class action lawsuit against honda ? Unsafe at any amperage? Where is ralph nader?

[66Overlander]

Both sides (generator Neutral-Ground bond "needed" vs. "unnecessary" at a generator) keep restating the same things in different ways, but unfortunately cannot seem to put it in words that allow the uneducated to resolve the issue in their minds.

As best I can see, if you are using a generator with your RV and these wires are not bonded at the generator and an open neutral occurs, the current that could potentially be sourced from the hot lead has no way back to the generator, thus no real safety risk unless touching the generator metal frame (assuming it is "grounded" internally - i.e. somehow internally connected to neutral) and trailer at the same time. It should be noted that in this case (hot connected, but no neutral or ground connected) one might measure up to full line voltage from the shell relative to the generator frame, but should not measure anything repeatable from shell to actual earth ground (i.e. to that proverbial 8' rod driven into the ground . . . unless the generator is earth grounded with such a rod, which I doubt generally happens in a portable generator situation with an RV), thus no risk of electrocution. Likewise, there should be no repeatable voltage measured between the hot wire and trailer shell in this situation - thus also no risk. But, if the possibility of touching the Airstream shell and generator frame at the same time with an open neutral concerns you, it seems that you should bond the ground at the generator.

The main value I see in using a surge protector/EMS with a generator would be protection from the fault condition of over or under voltage coming out of the generator, if you have the smart type that would disconnect the trailer for it's protection in that situation. In this case the neutral-ground bond is required at the generator for the EMS to work.

Does this about sum it up? Or am I missing something?

Bottom line. Bonding at the generator should not hurt anything but there is minimal risk if not done, and might provide a benefit very, very situations.

[TG Twinkie]

Originally Posted by uncle_bob

Hi

I guess we'll go back around this again ...

Ground is a wire in a plug. The name of the wire in the plug does not change depending on where the wire goes. It still is called the ground wire. Often it is green sometimes it is green and yellow. The name of the wire does not change when the color of the wire changes.

The ground wire is there to make you safe. If current flows in the ground wire, that's a bad thing. It's flowing to *keep* the current from hitting you. That's why it's there. You could easily call it the safety wire. For historical reasons we call it ground.

Neutral is a different wire in the plug. That wire is *supposed* to carry current. The voltage on that wire should not be very high. That's how we get the name neutral. You could also call it zero volts or you could call it return. Since calling it three different things is a bit confusing, we call it neutral. Normally it's a white wire. Again, if the color changes, the name does not change. It's the function that gives it the name.

Hot (and there may be more than one) is another wire in the plug. It's purpose is to supply voltage relative to the other hot leads and the neutral. If you have voltage, you can hook up a load and get current. You could call it supply or main or Bob. We call it hot. Usually it is a black or red wire.

Ok, so much for naming of wires. You will notice that the planet did not in any way get involved in the names of the wires. It's not part of the picture. Three wires and three names. One name for each wire.

Now, if any of these wires are not connected, that's a problem.

If the hot is not connected, you don't get voltage. No voltage means no current through the load. Nothing good happens. The circuit is dead. Throw the switch to the "ON" position and maybe you will hook up the hot wire.

If the neutral is not connected the current has no place to go back to the source. The load is "hot" in terms of voltage. There is no current. No current = nothing happens. Since there *is* voltage, don't poke your fingers in to see what's going on.

If the ground wire (remember it's just the name of a wire) is not connected, there is no safety return. Current (like from that open neutral) can leak to the housing of your gizmo. It has no place to go ( no neutral no ground) it's next best bet is going through you. This is *not* what you want to have happen.

In order for things to be set up *safely* the ground wire needs to be hooked to the neutral wire at the source of power. Hooking it to planet Earth is optional. Hooking it to neutral at the source is not. It's there to protect you. If you don't hook it up it will not do so.

If indeed this does not make sense to you, consult an RV electrician and have them check things out for you.

As with any safety system, you don't die the instant it goes out of whack. People survive all sorts of dangerous situations. That is *not* a reason to live dangerously.

Bob

And then you have the DC side of life where one side is refered to as "ground". WOW!
It's no wonder the novice is confused.

[rmkrum]

That’s why I try to put in the “Safety Earth” term when talking about the ‘ground’ wire in AC circuits. It better describes what the green wire is actually about. It’s there for safety.

[uncle_bob]

Originally Posted by 66Overlander

Both sides (generator Neutral-Ground bond "needed" vs. "unnecessary" at a generator) keep restating the same things in different ways, but unfortunately cannot seem to put it in words that allow the uneducated to resolve the issue in their minds.

As best I can see, if you are using a generator with your RV and these wires are not bonded at the generator and an open neutral occurs, the current that could potentially be sourced from the hot lead has no way back to the generator, thus no real safety risk unless touching the generator metal frame (assuming it is "grounded" internally - i.e. somehow internally connected to neutral) and trailer at the same time. It should be noted that in this case (hot connected, but no neutral or ground connected) one might measure up to full line voltage from the shell relative to the generator frame, but should not measure anything repeatable from shell to actual earth ground (i.e. to that proverbial 8' rod driven into the ground . . . unless the generator is earth grounded with such a rod, which I doubt generally happens in a portable generator situation with an RV), thus no risk of electrocution. Likewise, there should be no repeatable voltage measured between the hot wire and trailer shell in this situation - thus also no risk. But, if the possibility of touching the Airstream shell and generator frame at the same time with an open neutral concerns you, it seems that you should bond the ground at the generator.

The main value I see in using a surge protector/EMS with a generator would be protection from the fault condition of over or under voltage coming out of the generator, if you have the smart type that would disconnect the trailer for it's protection in that situation. In this case the neutral-ground bond is required at the generator for the EMS to work.

Does this about sum it up? Or am I missing something?

Bottom line. Bonding at the generator should not hurt anything but there is minimal risk if not done, and might provide a benefit very, very situations.

Hi

Yes, you are very much missing the safety feature of the so called "ground" wire. If it is floating, it provides no safety at all. You are back to the 1930's. The reason we went to 3 wire plugs is that people got killed this way. The ground and neutral very much *do* need to be bonded at one point. Un-bonded, there is absolutely no way to guess where the stray current will go. It *can* find a sneak path (is it raining out ....).

Why do generators not do this all the time? Because it would not be correct in all situations. If you are feeding a power box that *already* is bonded, then you very much do *not* want the generator to be bonded as well. You only want one point of connection. That's how the rules read.

Bob

[GOUSC]

Electrical Novice here again.

Based on what I just read, the answers to my questions should be;

With that background, Will I harm my trailer if I,

1. Use a bonding plug, and use my surge protector between the generator and the RV? No, my RV will not be harmed.

2. I am assuming by adding the surge protector in this chain will provide me with additional protection than I have had in the past. Is this a valid assumption or just an unnecessary step? Yes, it is a valid assumption in the instance that the generator does not supply correct voltage to the RV.

Is this the correct conclusion? We have 2 views of whether to use a bonding plug on a Honda 2000 or not.

As mentioned earlier I have not had any issues in the past of not using a bonding plug. I do not want to start using one and find out I created a problem where none existed before. If the above answers are correct, then IMO I don’t care which view is correct and I won’t put my RV or myself in any danger / risk by following the above practice.

[pdavitt]

Originally Posted by TG Twinkie

And then you have the DC side of life where one side is refered to as "ground". WOW!
It's no wonder the novice is confused.

A DC system has Positive + and Negative - voltage potentials. And the accepted practice is to bond the DC Negative to Ground at a point.

The confusion is caused by the slang usage of the word "ground" to refer to DC Negative. I believe it came about with vehicle DC systems where the battery DC Negative is connected directly to the chassis (ground). That way you only have to run a DC Positive wire to the load, the DC Negative is provided by a connection to the chassis.


Pat

[66Overlander]

Originally Posted by uncle_bob

Hi

Yes, you are very much missing the safety feature of the so called "ground" wire. If it is floating, it provides no safety at all. You are back to the 1930's. The reason we went to 3 wire plugs is that people got killed this way. The ground and neutral very much *do* need to be bonded at one point. Un-bonded, there is absolutely no way to guess where the stray current will go. It *can* find a sneak path (is it raining out ....).

Why do generators not do this all the time? Because it would not be correct in all situations. If you are feeding a power box that *already* is bonded, then you very much do *not* want the generator to be bonded as well. You only want one point of connection. That's how the rules read.

Bob

I see this as a "belt and suspenders solution" and nothing wrong with that. Eliminate all risk no mater how small. But I do understand the concept behind the addition of the "safety" ground wire. I am just trying to realistically understand how much risk is provided if the neutral and ground are not bonded. All of life is a gamble and each of us has our own level of risk tolerance. Me generally not too much. Best to understand the risks before making your own decision.

This is all hypothetical to me at this point as we just bought our first generator and have not used it with the Airstream yet, so I am just starting to think about these details.

[pdavitt]

Originally Posted by 66Overlander

I see this as a "belt and suspenders solution" and nothing wrong with that. Eliminate all risk no mater how small. But I do understand the concept behind the addition of the "safety" ground wire. I am just trying to realistically understand how much risk is provided if the neutral and ground are not bonded. All of life is a gamble and each of us has our own level of risk tolerance. Me generally not too much. Best to understand the risks before making your own decision.

This is all hypothetical to me at this point as we just bought our first generator and have not used it with the Airstream yet, so I am just starting to think about these details.

You are forgetting the financial risk. If someone visiting your trailer gets injured or killed, your insurance may not cover the liability since your system was not wired in accordance with "Accepted Standards and Practices" for electrical systems.

As you say, "your choice".
Pat

[OTRA15]

This earlier post has an example of the correct plug, I believe?

[click on orange arrow in quote to go there and see the photo]

Originally Posted by lsbrodsky

https://www.microair.net/products/ge...12272654155860

This is an example of what he is talking about.
Larry

Does anyone have an Amazon link for a similar product?

See:

http://ricksdiy.com/generators/porta...-honda-yamaha/
https://www.rvtravel.com/rv-electric...onding-basics/
https://www.rvtravel.com/how-generat...r-an-rv-works/
https://rvpartssource.com/southwire-44400

Thanks,

Peter

[66Overlander]

Originally Posted by pdavitt

You are forgetting the financial risk. If someone visiting your trailer gets injured or killed, your insurance may not cover the liability since your system was not wired in accordance with "Accepted Standards and Practices" for electrical systems.

As you say, "your choice".
Pat

Thanks Pat for pointing out another "technical" risk, though I think if the threat of a lawsuit moves one where a threat of someone getting shocked does not move them, then their priorities are wrong.

That said, as I think about this some more, I think I did miss something because I have not read one single post that has put all of the points together (at least none that made it entirely clear to me - several were probably clear in the mind of the poster).

I have been thinking about the "open neutral" condition because it was mentioned in some previous posts, but quite frankly, that is a rare condition that stands a good chance of being detected and corrected quickly, because with an open neutral, whatever it is that the generator was being used for (A/C, microwave, coffee pot, battery charging, etc.) would not be working, so this condition might quickly become obvious to the user.

The more insidious risk is with a properly connected neutral (but no "safety" ground). In this case everything in the trailer would work as intended, but if a "hot" wire shorts to the frame or shell the circuit breaker would NOT trip and the body of the Airstream ends up at line voltage potential (at least relative to generator "neutral"). In this case, one might experience a shock from the shell if there is some sort of unknown path back to the generator. This brings the previously mentioned "it's raining and you are standing in a puddle when you touch the trailer shell" condition into play.

In this case, with no neutral-ground bond at the generator, there is at least some risk of a shock, but were there a neutral-ground bond at the generator, the trailer shell would be held at "ground" potential and the breaker on the circuit that shorted to the shell should open.

To me, this is the more critical risk in the entire situation. The shock risk occurs when two (or maybe three) conditions are met:

1. No neutral-ground bond at the generator
2. A "hot" to shell short in the trailer
3. Some unknown current return path to the generator

Still a low probability of this set of conditions occurring, but certainly not "zero". I think this makes it clear that for me that I will chose to add a neutral-ground bond plug at the generator.

[lsbrodsky]

Originally Posted by OTRA15

This earlier post has an example of the correct plug, I believe?

[click on orange arrow in quote to go there and see the photo]

Does anyone have an Amazon link for a similar product?

See:

http://ricksdiy.com/generators/porta...-honda-yamaha/
https://www.rvtravel.com/rv-electric...onding-basics/
https://www.rvtravel.com/how-generat...r-an-rv-works/
https://rvpartssource.com/southwire-44400

Thanks,

Peter

Peter, this is the Amazon link for the Southwire plug

https://www.amazon.com/Southwire-Com...34786144&psc=1

Larry

[pdavitt]

Originally Posted by 66Overlander

Thanks Pat for pointing out another "technical" risk, though I think if the threat of a lawsuit moves one where a threat of someone getting shocked does not move them, then their priorities are wrong.

That said, as I think about this some more, I think I did miss something because I have not read one single post that has put all of the points together (at least none that made it entirely clear to me - several were probably clear in the mind of the poster).

I have been thinking about the "open neutral" condition because it was mentioned in some previous posts, but quite frankly, that is a rare condition that stands a good chance of being detected and corrected quickly, because with an open neutral, whatever it is that the generator was being used for (A/C, microwave, coffee pot, battery charging, etc.) would not be working, so this condition might quickly become obvious to the user.

The more insidious risk is with a properly connected neutral (but no "safety" ground). In this case everything in the trailer would work as intended, but if a "hot" wire shorts to the frame or shell the circuit breaker would NOT trip and the body of the Airstream ends up at line voltage potential (at least relative to generator "neutral"). In this case, one might experience a shock from the shell if there is some sort of unknown path back to the generator. This brings the previously mentioned "it's raining and you are standing in a puddle when you touch the trailer shell" condition into play.

In this case, with no neutral-ground bond at the generator, there is at least some risk of a shock, but were there a neutral-ground bond at the generator, the trailer shell would be held at "ground" potential and the breaker on the circuit that shorted to the shell should open.

To me, this is the more critical risk in the entire situation. The shock risk occurs when two (or maybe three) conditions are met:

1. No neutral-ground bond at the generator
2. A "hot" to shell short in the trailer
3. Some unknown current return path to the generator

Still a low probability of this set of conditions occurring, but certainly not "zero". I think this makes it clear that for me that I will chose to add a neutral-ground bond plug at the generator.

Joe,
Sometimes you just have to trust the experts. In this case the NEC, NFPA, ABYC, etc. In my line of work you "Go with the Code".
Pat

[OTRA15]

Thanks Larry for that link.

Peter

[ROBERTSUNRUS]

Hi,

(1.) For those concerned about a law suit, wouldn't that include modifying your generator?

(2.) Extremely rare, but what happens when you bootleg your ground and your neutral becomes open?

(3.) Automotive DC grounds are mostly negative ground; Older cars with six volt systems were for the most part positive ground.

[xrvr]

Post 102 was in jest.

[uncle_bob]

Hi

I seems we still have not covered everything .... yikes ....

Electrical faults:

Your trailer is wired up with wire nuts and solid wire. It gets subjected to vibration. Maybe things last forever, maybe not so much. Wire nut fails off of here or there. Wires hit the skin. This is *not* a good thing. If that's the hot wire and you have no ground bonding, the skin of the trailer is hooked to hot. It only takes a small fraction of an amp to kill you.

Your generator is sitting out in the rain on the ground. Mud is everywhere. It's created a path. There is a one in three chance it's to the neutral. If it's to an un-bonded ground it doesn't matter so really it's one chance in two. There is *always* a path in this case.

It only takes a fraction of an amp to kill you dead. Feet on the wet ground and hand on the metal door handle is a perfect setup to do so. Dead is dead. You don't get a second chance.

https://www.asc.ohio-state.edu/physi...l_current.html

This is far from the only case. Bugs have a Wonderful tendency to get in everywhere. Mr Dead Bug is quite capable of creating enough of a path to kill you. So is a dead mouse. I've run into both issues multiple times over the years.

There's the Wonderful extension cord that goes from the generator to the trailer. It flops around in the back of the truck and sits out on the ground. People walk on it. Kids ride bikes over it. Stuff gets loaded on top of it. They die and in some cases do so with exposed wire. I've seen more than one explode into a shower of sparks.

In terms of "remote chance", back before WWII pretty much everything was wired without a ground (safety) wire. A statistically significant number of people died every month as a result. The risk is indeed real and it does kill.

You might ask - isn't this a "two things happen at once" sort of issue? Well not so much. The first thing fails and without a ground, you don't notice the failure. You go on and ignore it. There is no obvious way it tells you it's failed. When the second part of the path is created ... you are in real trouble.

So no, this is not some sort of hypothetical / never happens to anybody sort of thing. It has killed many people in the past. It can and will kill people in the future. It does not show up on the news because it's very much "dog bites man".

======

Confusing AC circuit wires with other wires with the same names is not going to do you any good. Low voltage DC is a completely different animal than residential voltage AC. The practices are different and the shock fatality risk (at 6 or 12V) is essentially zero. You don't do automotive DC the same way you do AC.

====

Lawsuit wise, if you have just killed somebody (or even just knocked then out cold), is a lawsuit the only thing on your mind? If so, you aren't getting on my Christmas list any time soon. Safety is about more than being sued.

====

Here's another gotcha: There is no downside to doing the right thing. Bonding ground and neutral is not hard. It is not expensive. It does not take a lot of time. Every person in this thread has taken more time typing these messages that it would take to "fix" a setup. We're not talking about man months of labor or thousands of dollars of cost here.

This is *not* one of those nutty / obscure things that maybe you don't worry about. I certainly don't get excited about every little electrical issue there is. This one *is* on the short list of things you *should* take care of. ( Having a multimeter to check things is also on that list).

======

We can go off and come up with other situations that can happen but aren't fixed by bonding ground and neutral. This is not a single fix for all the worlds problems. We have ground fault and arc fault interrupters *because* it's not a single solution. Even so, bonding the ground wire makes them a lot more likely to do their job ....

Bob

[xrvr]

Only a fool uses a generator in the rain uncovered. Continuing preaching to those withno common sense or worse accomplishes nothing. Waste of time.

[66Overlander]

Originally Posted by pdavitt

Joe,
Sometimes you just have to trust the experts. In this case the NEC, NFPA, ABYC, etc. In my line of work you "Go with the Code".
Pat

Part of the trouble is that there are so called "experts" on both sides of this argument and most of the rest of us have never read "the code", nor would even know where to find it.

Of course by "so called experts" I mean people that pasionately believe their opinions/positions. This passion can make it tougher for others to wade thru the "debate" to determine the real facts without going to find "the code" themselves.

I thank those that know "the code" for sharing their knowledge.