My trailer got fried!

[uncle_bob]

Hi

A shorting plug is a very normal looking gizmo that simply has the ground lug connected to the neutral pin. Some generators need them, others do not. We could go on and on about if they should be part of the generator or not.

If you do a continuity check on your generator with your multimeter (we all have multimeters ... right???) you will get zero ohms between ground and neutral on a generator with a "built in short". You do the check with the generator off ... . If yo get zero ohms, then you don't need a shorting plug.

If you don't get zero ohms you get to make a decision:

1) If you only use the generator for RV use, put in a wire inside the generator to short the two together. Label the generator so you remember that's what you did.

---- or ----

2) If the generator has a really weird plug / adapter cable to hook up the RV, rewire that plug to connect the wires. Again, label it so you know what you did. Maybe check the plug with the ohm meter first, just in case it's already shorted.

---- or ----

3) Rig up a plug with the two wires connected and it goes into one of the sockets on the generator. (yes label it and maybe leave it in the generator).

--- or ---

4) Spend money and buy one of the plugs that do the job.

=================

Coming back to the start:

If you don't have a multimeter, go get one now. They need to be part of your tool kit in the RV. There are a *lot* of things to master when you are out and about. Lots of interesting new tools to stock up on. The $20 one from Lowes or Home Depot is "good enough". Yes, something from Fluke is better.

Next is to spend a bit of time with YouTube and learn the basics of measuring this and that. It's less than an hour, including all the random videos you will get distracted by. Better to play with the gizmo and learn how it works *before* you need it for real.

What's it good for:

1) I wonder what my battery voltage *really* is? A multimeter and a temperature / voltage chart is the only way to be sure how well the battery is charged.

2) I wonder if that socket is wired right? (yes a plug in gizmo will tell you some of that).

3) I wonder if the campground power post is wired correctly / working right? (... part of the advanced course ...)

4) I wonder if the generator needs a shorting plug?

5) Is that USB outlet safe to plug my expensive phone into?

6) How much power does this use? (also part of the advanced / clamp amp part of the course = you spend more than $20 for that feature ).

7) Is my converter / charger (or solar charger) working ?

8) Why do I get this tingle when I touch the skin of the trailer ? ( .... and why do I need to fix that before it kills me ....).

9) Whats going on with the left rear turn signal?

....... and on and on ....

Get the multimeter. It's a lot more important than a shorting plug. Use it as an excuse to "learn up" on basic electricity / wiring. You *will* need to understand what's going on at some point down the road. Two hours from nowhere with zero cell coverage is *not* the place to start the learning process ....

Bob

[blkmagikca]

Also, ensure that your surge protector has a time delay before it engages, so that when you start your generator it has time to get up to full output before the connection is powered. When I had an AS LY moho with a 6.5Kw genset, there was a time delay relay (60 seconds) in the ATS to allow the power to be stabilized.

[Ephraim]

Originally Posted by A W Warn

There is no one answer that fits all Honda generators. Some are bonded, some are not. Generally, inverter generators have a floating neutral, not neutral/ground bonded. Your owners manual should address your generator spefically.
I know that my Honda 2000 is not bonded.
I know that my Predator 3500 is not bonded.
I do not, nor have I ever used a bonding plug. I see no reason for it.

Since a portable generator is not connected to earth (grounded), unless a ground rod is driven or some other grounding electrode connected (eg: metal pipe that runs underground), and then connected by a wire to the ground lug on the generator, there is no ground.
Therefore, a plug in circuit tester will not work properly without the jumper plugged into the generator. Adding a bonding plug does not add a ground, it just fools the testing device.

Again for emphasis, there is no ground with a portable generator unless special provisions are made to connect the generator to earth.

The reason for grounding is to shed excessive load to earth (from accident, lightning, or other surge from utility)

ps:
Off subject but:
Confusion happens when 12v DC negative (-) is referred to as ground. A battery DC system does not require a ground (to earth), though ground in an alternating current AC system and direct current DC negative can be, and are, simultaneously connected in our trailers,.

There is no magic to an "earth" ground. The power companies use Earth as a common point, but you do not have to with a generator. If you are creating a network of generators, the earth ground is an easy common point because it is a continuous common point, but you could just as easily use wires. the point is to have a safety conductor that is the last to break continuity. (i.e. if you have a misconfigured power pylon that puts voltage somewhere it shouldn't, the power feed line should break before the ground line. that way the return for power always has someplace to go other than through your body.)

A grounding plug on the generator is not fooling anything. It is providing a bond between neutral and ground that would normally occur (due to code) at the breaker box right next to the power meter. since you are not connected to utility power when running a generator, the bonding plug is an OK way to create that bond. the drawback is that it is not a permanent bond and can be removed which creates a potential safety issue since the return line must be the last to break in the circuit. If you don't have that bond and there is an issue (either from a pylon miswire, trailer miswire, or even a broken wire), you may end up like turk123.

by the way, if the ground is smoking because of a ground wire, there are really big problems somewhere. Current should never be flowing through the earth ground.

for those asking, Honda produces the 2000 generator two ways. the "commercial grade" are typically bonded. for most uses, an unbonded generator is OK, but is desirable. If you are tying two generators together, only one should be bonded. the plug is a good thing, but you must know whether it needs to be used or not when using your generator. for our purposes, it generally should be used on an AS trailer.

You can run into issues when using a bonded generator on a trailer that is not yours because you don't know if the trailer has been bonded internally or not.

[xrvr]

Originally Posted by Paprika

"Everyone at Alumapolosa, Airstream Life and Airstream stepped up to the plate and said they would cover all the damage."

That's good as far as it goes. But when you were adjusting your hitch and were knocked over by the live 110 V charge on every metal part of your rig, you could easily have been killed--in fact, if the ground had been wet, you probably would have been. There is no amount of money that can "repair" a fatality.

Regardless of whether the event was officially sponsored by Airstream, they should never have allowed this situation to occur on their property. It's a safe bet their insurance company would be horrified if they read your account.

Yes but if you readback carefully you will see where someone did not follow directions,ie the rules and created thee situation. The short wouldnot have occurred because the system wouldnot havebeen overloaded. See postnumber 18.

[A W Warn]

Originally Posted by uncle_bob

Hi

A shorting plug is a very normal looking gizmo that simply has the ground lug connected to the neutral pin. Some generators need them, others do not. <<snip>>

Bob

I do not understand the "need" part of your statement.
What is the benefit of bonding ground to neutral in any portable generator used only for a travel trailer?

[Ephraim]

Originally Posted by A W Warn

I do not understand the "need" part of your statement.
What is the benefit of bonding ground to neutral in any portable generator used only for a travel trailer?

An unbonded generator should have one if it is the only AC power source feeding the trailer. As per my earlier comment, the point of the bonded (at the power source) ground is to provide a conductor that is the last to break in any real or potential connection. that way, if there is a problem, there is always continuity for the power flow that is somewhere else other than through your body.

A commercial grade generator that is already bonded does not need the bonding plug.

A regular generator with a floating ground/neutral does need the bonding plug.

A second generator in a paralleled generator set does not need the bonding plug.

A generator feeding a trailer that has been inappropriately bonded in the breaker panel probably should not have the plug. In this case, the appropriate action is to remove the bond in the breaker panel and then use the bond at the generator.

[A W Warn]

Originally Posted by Ephraim

There is no magic to an "earth" ground. The power companies use Earth as a common point, but you do not have to with a generator. If you are creating a network of generators, the earth ground is an easy common point because it is a continuous common point, but you could just as easily use wires. the point is to have a safety conductor that is the last to break continuity. (i.e. if you have a misconfigured power pylon that puts voltage somewhere it shouldn't, the power feed line should break before the ground line. that way the return for power always has someplace to go other than through your body.)

A grounding plug on the generator is not fooling anything. It is providing a bond between neutral and ground that would normally occur (due to code) at the breaker box right next to the power meter. since you are not connected to utility power when running a generator, the bonding plug is an OK way to create that bond. the drawback is that it is not a permanent bond and can be removed which creates a potential safety issue since the return line must be the last to break in the circuit. If you don't have that bond and there is an issue (either from a pylon miswire, trailer miswire, or even a broken wire), you may end up like turk123.

by the way, if the ground is smoking because of a ground wire, there are really big problems somewhere. Current should never be flowing through the earth ground.

for those asking, Honda produces the 2000 generator two ways. the "commercial grade" are typically bonded. for most uses, an unbonded generator is OK, but is desirable. If you are tying two generators together, only one should be bonded. the plug is a good thing, but you must know whether it needs to be used or not when using your generator. for our purposes, it generally should be used on an AS trailer.

You can run into issues when using a bonded generator on a trailer that is not yours because you don't know if the trailer has been bonded internally or not.

Originally Posted by Ephraim

An unbonded generator should have one if it is the only AC power source feeding the trailer. As per my earlier comment, the point of the bonded (at the power source) ground is to provide a conductor that is the last to break in any real or potential connection. that way, if there is a problem, there is always continuity for the power flow that is somewhere else other than through your body.

A commercial grade generator that is already bonded does not need the bonding plug.

A regular generator with a floating ground/neutral does need the bonding plug.

A second generator in a paralleled generator set does not need the bonding plug.

A generator feeding a trailer that has been inappropriately bonded in the breaker panel probably should not have the plug. In this case, the appropriate action is to remove the bond in the breaker panel and then use the bond at the generator.

For the most part, everything you said agrees with what I said.

I understand the need for grounding and bonding when power is suppled from a utility.

I know that grounding a portable generator connected to a single travel trailer and bonding its neutral to ground sets up the potential for the hot skin condition. So, doing this actually sets up a hazard.

What is the "need" for bonding a portable generator when connected to a single travel trailer?

[OTRA15]

Originally Posted by A W Warn

. . .
What is the "need" for bonding a portable generator when connected to a single travel trailer?

Other curious folks would also like to know.

Thanks,

Peter

[Ephraim]

Originally Posted by A W Warn

For the most part, everything you said agrees with what I said.

I understand the need for grounding and bonding when power is suppled from a utility.

I know that grounding a portable generator connected to a single travel trailer and bonding its neutral to ground sets up the potential for the hot skin condition. So, doing this actually sets up a hazard.

What is the "need" for bonding a portable generator when connected to a single travel trailer?

If the trailer is NOT bonded in the breaker panel (as it shouldn't be), You do not set up the danger. You actually alleviate the danger.

IF you have a neutral conductor failure so that the ground carries current, your trailer skin should be floating in relation to earth ground unless you are powered by the utility pylon. Bonding the Neutral/Ground at the generator does not create an unsafe path for the electricity unless you have something else seriously misswired. Floating does not mean that it will carry current (that's the reason birds can land on a power line without being electrocuted). Bonding your generator puts you in the same safety arena as being powered by a utility pylon. It's the safest condition.

[A W Warn]

You keep mixing your answers with combinations, regarding utility power and generator power. Let's stick to the generator part.

If a generator is grounded and bonded, in the event of a fault within the trailer there is a potential circuit through a human body, trailer skin to earth ground.

If a generator is not grounded and bonded, there is no potential circuit through a human body to ground through the trailer skin, therefore that hazard does not exist.

ps
I do not agree with "Bonding your generator puts you in the same safety arena as being powered by a utility pylon. It's the safest condition. "

[Ephraim]

Originally Posted by A W Warn

You keep mixing your answers with combinations, regarding utility power and generator power. Let's stick to the generator part.

If a generator is grounded and bonded, in the event of a fault within the trailer there is a potential circuit through a human body, trailer skin to earth ground.

If a generator is not grounded and bonded, there is no potential circuit through a human body to ground through the trailer skin, therefore that hazard does not exist.

ps
I do not agree with "Bonding your generator puts you in the same safety arena as being powered by a utility pylon. It's the safest condition. "

Now your mixing answers. Where is the generator bonded to "earth ground"? given that there must be continuity for power to flow, unless you have a ground stake (or other such metal earth ground) at the generator, power will not flow from the trailer skin to earth ground. Bonding neutral/ground at the generator does not magically create current through earth ground. If you have an issue, it merely provides a secondary conductor to complete the circuit back to the generator through the ground wire. Your trailer ground is NOT earth ground unless you are connected to an earth ground (utility power or a grounding rod of some sort).

If your trailer has a wiring issue where power flows through the ground you are much, much safer than if it flows through you while finding a return path.

In any case, power will more readily flow through the metal of the trailer as it finds it's way back to the generator than you standing on the ground through a non-existent return path. Having the bonded Neutral/Ground at the power source is ALWAYS safer than not having it.

There are rare cases where having a floating ground is better, but they do not exist in a properly wired house/TT when dealing with power. don't argue with me, argue with the state wiring codes in EVERY state. yes, those codes will grant you exceptions, but they are generally for special use situations.

House wiring codes are usually more stringent that TT wiring codes. Not because trailers are different, but because more people live in houses that TT.

[Al and Missy]

What Alan said. The only reason to put a ground rod at a trailer is because the shore power is referenced to ground some distance away and the earth potential at the trailer can be different from that point, thus a shock from the trailer skin to ground can occur.

When using a generator that is not referenced to ground, there should be no shock hazard. Even if the hot and neutral or hot and ground somehow get crossed in the trailer, there is no reference to earth ground and therefore, no shock hazard.

The only reason for a bonding plug is to clear the error in a power protection system when the generator does not have neutral bonded to ground and the protection system wants to see one.

There is no reason not to put a ground rod at the trailer; it just is not really necessary on a generator and only provides marginal benefit (if any) when hooked up to shore power.

Al

[garry]

The one time you will wish you had a grounding plug at the generator.
Should you have a ground fault (short ground to neutral) in the trailer and you touch the generator and trailer at the same time you become the return path and that hurts that is the safety of a grounding plug.

Basic electricity (current or amps) will never ever leave it's starting point if it cannot see all the way back to where it started from so without the grounding plug in a generator electricity (current) will never leave the generator with an open neutral.

[xrvr]

So one of the internet experts here is saying all those thousands of honda generators being used are unsafe. Please sell them cheap, i am interested in a few dozen. They are unsafe! I also have grounding pipes available.

[AirstreamInc]

Originally Posted by turk123

We are at Alumapolosa and are at the Holloway camp area. The Airstream folks provide a Hodge podge of electrical wiring and 4 trailers split 20 amps. When we hooked up the electrical my outer skin was electrified! They brought back the electricians to repair the lines on the ground. Yesterday I adjusted my hitch and as I was kneeling and grabbing the hitch, I got knocked backward by a charge of electricity.

In the afternoon a wire nut got hot and melted through so the wires shorted against the metal box. It sent the voltage through 8 trailers including mine. It completely fried two trailers converters, blew out a surge protector and fried my HDMI mono price box and melted my HDMI cables ends.

I am now getting power on the skin of the trailer. It has shorted something to the metal.

I talked with Airstream service today and they sent a guy our to look. He did not find a short. I took my fried splitter box into service and the had another they gave me. They also set an appointment for 7 AM tomorrow to see if they can determine why power is shorted to the body. This is serious as it is a full 120 volts at 20 amps. They can't replace one of the HDMI cables running to the bedroom as it takes about 6-7 hours to run to that area.

We have an appointment in mid-July for this and all the other stuff we need to be fixed. If they can't find the short, we will be without our trailer for the summer.

Not a very good end to a great two-month trip. I hope they find the short tomorrow so we can be safe.

Hi Turk123,

We're sorry to hear about what happened. As mentioned on this thread, we host the event that Airstream Life produces. We're working with organizers and our service department to better understand what happened. Please don't hesitate to reach out if you need additional assistance.

Thank you.

[Hittenstiehl]

Waninae, I hear your concern but calling the city police or code inspectors is way unnecessary. They have their expertise areas but private events on private property or daisy chaining a couple of RVs together would likely not be one of them unless they are campers.

Electricity is a very serious matter and should be highly respected at all times.

But this IS how it was safely done and is still done in big rallies. Thinking it will likely be discontinued soon as people have a lot more electrical devices in their trailers now. Many people don't understand the need to run it very sparingly.

Rally's of this size are often hundreds or thousands of trailers in the middle of a farm field. Can't all run a generator otherwise you wouldn't be able to breathe or hear but yes you can't also go around electrifying trailers.

[ROBERTSUNRUS]

Originally Posted by Al and Missy

What Alan said. The only reason to put a ground rod at a trailer is because the shore power is referenced to ground some distance away and the earth potential at the trailer can be different from that point, thus a shock from the trailer skin to ground can occur.

When using a generator that is not referenced to ground, there should be no shock hazard. Even if the hot and neutral or hot and ground somehow get crossed in the trailer, there is no reference to earth ground and therefore, no shock hazard.

The only reason for a bonding plug is to clear the error in a power protection system when the generator does not have neutral bonded to ground and the protection system wants to see one.

There is no reason not to put a ground rod at the trailer; it just is not really necessary on a generator and only provides marginal benefit (if any) when hooked up to shore power.

Al

Hi, I'm reading RED.

[uncle_bob]

Originally Posted by A W Warn

I do not understand the "need" part of your statement.
What is the benefit of bonding ground to neutral in any portable generator used only for a travel trailer?

Hi

If you are connected to a generator *and* the ground is *not* bonded to neutral in any way, then it's floating. If there is a short to ground, no current will flow. The safety feature provided by the ground wire has been defeated in this case.

The same is true in any "loose ground" situation. That may or may not have been part of the problem that started this thread. A "hot skin" is one of the indications, but not a 100% guarantee. There can be other reasons.

With a floating ground, things like ground fault circuit breakers get easily confused ( = provide no protection / trip randomly ). Since most AS trailers have them, this alone is a good reason to bond the ground.

A lot of electronic gear has filtering on the input. That filtering returns a minor amount of current to ground and puts an un-bonded ground at about 60V. It will not kill you, but it will give you a tingle. Not something you want to put up with all the time. (I learned this one back in the 60's .... when 3 prong plugs were not as common ... errr ... ).

Is a plug going to solve all the issues that can come up? Of course not. You still are floating relative to "earth". Leakage will put you somewhere / who knows where relative to the planet. Since the skin and frame of the trailer and generator are grounded, it's *likely* that leakage will put that close to the planet.

Now, toss in a cable TV connection. That coax shield probably *is* tied to a real ground somewhere. It also probably is tied to the electrical ground in your trailer through the TV or other gear. Hmmmm ..... probably not a good idea to have one hand on the cable connector and the other on the trailer when hooking things up at random campsites ... hmmm ....

Lots of variables.

Bob

[A W Warn]

Thank you!
I'll test my GFCI circuit while connected to my generator, without a bonding plug.
I was under the impression the GFCI would work correctly, since the device should sense differential voltages between line and neutral.

Boondocking with cable TV Having cable while on the generator would rarely be an issue.

[rmkrum]

True. The GFCI will work properly because it only detects hot-Neutral current imbalance to function.

However, it points out the problem of ground connection bonding to the same point. In this case, if the only ‘ground’ connection is the skinny cable TV wire, a surge or lightning strike can only get to earth through that skinny wire. Which will most likely literally explode. That’s why all ground conductors in a system need to be tied to a single ground point for safety.