Seahawk Highlights Video (206) 949-5683, Top Rated Plumber, Seattle

# Thread: Grounding a portable generator

1. Not that the support guy knows anything about grounding..but if you happen to talk to him again ask him HOW A GROUND ROD PREVENTS SOMEONE FROM A SHOCK.

2. Originally Posted by BrianJohn
Not that the support guy knows anything about grounding..but if you happen to talk to him again ask him HOW A GROUND ROD PREVENTS SOMEONE FROM A SHOCK.
I did just that. I replied saying:

"Out of curiosity, how does a ground rod on a stock Coleman Generator
(without receptacle ground bonded to the frame) prevent someone from
being shocked?"

"It's mostly to prevent an accidental shock it the machine would happen
to get wet. Instead of the electricity traveling through the frame it
would travel out through the ground. "

3. "It's mostly to prevent an accidental shock it the machine would happen
to get wet. Instead of the electricity traveling through the frame it
would travel out through the ground."

Send them this.

Are you out of your ever loving mind! If the electricity travels THROUGH the ground (which by the way is a less than a fair conductor) where is it going too!

Mother Earth is the harbinger of a lot of things but she could care less if a Coleman generator exist and/or much less if is connected to her backside by means of a STICK IN THE EARTH.

In a short of an energized conductor the the voltage is going to return to it's source, generally by the path of least resistance, though any viable paths may share some of the fault current. We call it a circuit because it is CIRCULAR starts and ends in the generator.

from Wikipedia

An electrical circuit is a network that has a closed loop, giving a return path for the current. A network is a connection of two or more components, and may not necessarily be a circuit.

Oh well hopfully you have your answer to the original post and Coleman is much bigger than me they will continue to do what they do and many if not most electricians, inspectoers and end users will continue to drive ground rods, which in it's self is not bad*, but unecssary

*Unless you hit a high voltage underground cable.

4. Originally Posted by Cubey

"It's mostly to prevent an accidental shock it the machine would happen
to get wet. Instead of the electricity traveling through the frame it
would travel out through the ground. "

I wound then ask, "To where?......" It isn't like a bucket of popcorn that can spill out and make a mess. Electron flow is not affected much by gravity.

Electricity needs a compete circuit in order to flow. If there's a short-circuit in the unit itself, and it is properly bonded and grounded within itself, then the breaker will open.

5. Sparky you know durn well that the earth is a gigantic bucket for electrons just waiting to suck up the extra/spare electrons from our wiring errors.

6. Having spent some time in the military, grounding things became a big hassle. We often had multiple things connected to separate generators, maybe stuck on top of a mountain, where you couldn't really drive a ground stake. That took some real effort to keep from getting yourself knocked on your butt sometimes. Often it was just to ensure you could drain off a significant static buildup.

FOr a single generator on a single device, a ground rod probably isn't that big of a deal. When you are trying to establish ground planes for things like communications or radar sets, it becomes much more problematic. In the desert, the cooks would order lots of extra salt, and salt down then keep moist the ground rods/cables in order to have a phone or radio system work properly. Sand is a lousy conductor, so a ground rod(s) or burried array of cables often wouldn't work well.

This was more for noise and ground plane, not for safety, although that did come into play as well. It also helped with near (but not direct) lightning strikes.

I wouldn't worry about grounding a generator on an RV. Then again, I don't have one nor am I a licensed electrician.

7. Originally Posted by 480sparky
I wound then ask, "To where?......" It isn't like a bucket of popcorn that can spill out and make a mess. Electron flow is not affected much by gravity.

If there's a short-circuit in the unit itself, and it is properly bonded and grounded within itself, then the breaker will open.
Not much point in asking them anything else. They already admitted that in some cases they don't think you have to drive a rod if the ground in the receptacle is bonded to the generator's frame. A short piece of 12 gauge wire added on would correct this anyway and make it compliant to not needing a ground rod (according to the Coleman support guy anyway).

If in doubt of it already being bonded, I could do it anyway though that could possibly cause a ground loop if it already has ground bonded to the frame but thats about the only risk in adding it. I am already familiar with installing receptacles, switches, light fixtures, etc so routing ground to frame will be no problem at all.

I assume the breaker you refer to are the ones at the trailer's panel.

Going back to a question I asked a bit ago, since I don't think I got an answer or I forgot it and can't find where it answered, should neutral be bonded to ground/frame at the generator? I know it shouldn't be at the trailer's panel. Might be good to play it safe and manually bond neutral to ground just to be safe if it is supposed to be that way.

8. Originally Posted by BrianJohn
Sparky you know durn well that the earth is a gigantic bucket for electrons just waiting to suck up the extra/spare electrons from our wiring errors.
From a portable genny? How do you complete the circuit?

The earth may be capable of 'sucking up' all those electrons that trickle off by screwdriver or I spill out of my pouch, but then how do they get back to the generator?

9. it is FM F***ING MAGIC

10. Originally Posted by Cubey
Going back to a question I asked a bit ago, since I don't think I got an answer or I forgot it and can't find where it answered, should neutral be bonded to ground/frame at the generator? I know it shouldn't be at the trailer's panel. Might be good to play it safe and manually bond neutral to ground just to be safe if it is supposed to be that way.
If the neutral point of the generator is not bonded to the equipment grounding conductors supplied by the generator then the overcurrent device will not operate properly.

We know that the grounded (neutral) must be isolated from the equipment grounding conductors in the distribution panelboard inside the RV as outlined below;
551.45 Distribution Panelboard.
(A) Listed and Appropriately Rated. A listed and appropriately rated distribution panelboard or other equipment specifically listed for this purpose shall be used. The grounded conductor termination bar shall be insulated from the enclosure as provided in 551.54(C). An equipment grounding terminal bar shall be attached inside the metal enclosure of the panelboard.

The lack of bonding the equipment grounding conductors to the grounded (neutral) conductor in the panel inside the RV makes the generator a separately derived system and must be treated thus.

The equipment grounding conductors do not bond in the panel inside the RV so any fault to any metal including the shell of the unit could not return through a path of low-impedance and if the equipment grounding conductors don’t bond to the grounded (neutral) at the generator either then there is a problem.

By bonding the generator the low-impedance path is established and now any and all of the overcurrent devices can function as they were designed.

The driving of a ground rod will play no role in the operation of any overcurrent device and will only protect the generator in the event of lightning, line surges, or unintentional contact with higher-voltage lines. I can’t see either of the latter two taking place if the same cord is used to supply the RV being used from either the generator or the pedestal.

11. Originally Posted by jwelectric
If the neutral point of the generator is not bonded to the equipment grounding conductors supplied by the generator then the overcurrent device will not operate properly.

We know that the grounded (neutral) must be isolated from the equipment grounding conductors in the distribution panelboard inside the RV as outlined below;
551.45 Distribution Panelboard.
(A) Listed and Appropriately Rated. A listed and appropriately rated distribution panelboard or other equipment specifically listed for this purpose shall be used. The grounded conductor termination bar shall be insulated from the enclosure as provided in 551.54(C). An equipment grounding terminal bar shall be attached inside the metal enclosure of the panelboard.

The lack of bonding the equipment grounding conductors to the grounded (neutral) conductor in the panel inside the RV makes the generator a separately derived system and must be treated thus.

The equipment grounding conductors do not bond in the panel inside the RV so any fault to any metal including the shell of the unit could not return through a path of low-impedance and if the equipment grounding conductors don’t bond to the grounded (neutral) at the generator either then there is a problem.

By bonding the generator the low-impedance path is established and now any and all of the overcurrent devices can function as they were designed.

The driving of a ground rod will play no role in the operation of any overcurrent device and will only protect the generator in the event of lightning, line surges, or unintentional contact with higher-voltage lines. I can’t see either of the latter two taking place if the same cord is used to supply the RV being used from either the generator or the pedestal.
So is that a "yes" to bonding neutral and "ground" of the generator to the gen's frame manually myself if I'm unsure if it already wired up that way?

If so, would that be a safe way to do it?...
Remove the cover where the receptacles are, link the neutral to ground on all the receptacles with a few short pieces of 12 gauge wire (preferably green insulated wire so it will be properly color coded) and then run a long 12 gauge wire down to the screw that Coleman put for using a grounding rod and attach it there. Oh wait.. I might have to run that wire to the frame, not the screw. Might have to do both actually just to be sure its done properly. Link the 12 gauge wire from neutral/ground bonding at the receptacles to the screw meant for a ground rod and then link the screw to the frame. That would be a full proof way of making sure everything is bonded properly and is attached to the frame.

As I understand it about the RV panel, it is considered a "sub panel" under the NEC code and so neutral & ground must be isolated there. This is because the power source it is getting is supposed to be properly bonded either in a main breaker panel such as in a house, an RV park/campground outdoor breaker panel with GFI receptacles, or bonded at the generator.

(Note: If i say ground I am referring to the wire that goes to the 3rd prong on a 15A receptacle. You seem to do otherwise. I'm confused by the various usage of ground vs grounded vs grounding so I'm keeping it simple by saying "neutral" & "ground")

12. Originally Posted by Cubey
So is that a "yes" to bonding neutral and "ground" of the generator to the gen's frame manually myself if I'm unsure if it already wired up that way?

If so, would that be a safe way to do it?...
I would recommend that you have this done by a professional. It needs to be done internal of the generator such as this illustration shows.

Here the bond was removed because the “bonding” took place at the main for the building. The “bonding” can not occur at both the generator and the building.

Originally Posted by Cubey
Remove the cover where the receptacles are, link the neutral to ground on all the receptacles with a few short pieces of 12 gauge wire (preferably green insulated wire so it will be properly color coded) and then run a long 12 gauge wire down to the screw that Coleman put for using a grounding rod and attach it there. Oh wait.. I might have to run that wire to the frame, not the screw. Might have to do both actually just to be sure its done properly. Link the 12 gauge wire from neutral/ground bonding at the receptacles to the screw meant for a ground rod and then link the screw to the frame. That would be a full proof way of making sure everything is bonded properly and is attached to the frame.
NO! NO! NO! this is not the way to “bond” the generator and is doing nothing but causing a more dangerous situation.

Originally Posted by Cubey
As I understand it about the RV panel, it is considered a "sub panel" under the NEC code and so neutral & ground must be isolated there.
There is no such animal called a “subpanel” this is a phrase that has been picked up in the field and has no meaning in the NEC.
What makes the distribution panelboard get called “subpanel” is what is supplying the panel. Every panel is supplied by either feeders or service entrance conductors. The RV is supplied through feeders by both the pedestal or generator as either are required to have overcurrent protection for the conductors connected between them and the RV.

Originally Posted by Cubey
This is because the power source it is getting is supposed to be properly bonded either in a main breaker panel such as in a house, an RV park/campground outdoor breaker panel with GFI receptacles, or bonded at the generator.
This is correct

Originally Posted by Cubey
(Note: If i say ground I am referring to the wire that goes to the 3rd prong on a 15A receptacle. You seem to do otherwise. I'm confused by the various usage of ground vs grounded vs grounding so I'm keeping it simple by saying "neutral" & "ground")
Well it is easy to understand what each is called and what each is supposed to do. The words “ground vs grounded vs grounding” simply mean connect to mother earth. The terms "neutral" & "ground") say the same thing, connected to earth.
The one word you have left out is the most important and it is called “bonding” and means that the conductors you mentioned have been connected together at the point where the supply of current is taken and in this case the generator.

In earlier post I have pointed out that ANY and ALL generators used for a RV must be listed for the use. Look carefully at the section of the NEC posted below.

551.32 Other Sources.
Other sources of ac power, such as inverters, motor generators, or engine generators, shall be listed for use in recreational vehicles and shall be installed in accordance with the terms of the listing.
Other sources of ac power shall be wired in full conformity with the requirements in Parts I, II, III, IV, and V of this article covering 120-volt electrical systems.

Yes I know and understand that a lot of people do not know about this section and just as many do not understand the requirements of bonding these systems.

In my area there is a slew of RV parks and I get calls all the time about someone using a generator that is not bonded and feeling a tingle on rainy days until I ask on the phone about the electrical connection before I go out on the call. 99% of these calls are about the remote generator that is not properly listed for the use and are not bonded.

The part I like best is when it is still raining and the generator has been set inside a cavity of the RV to protect it from the weather. Now it just became a mounted generator and I recommend to the park manager to either have the RV owner sign a wavier of liability or evict then from the park.

The NEC does not require that the generator being used on a RV be listed because the NEC is making a lot of money from the sale of listed generators but instead the NEC requires that generators be listed for the purpose as a safety issue.
The danger comes when the RV owner wants to save a little money and buy something just because it works without understanding the danger involved.

13. I believe that Part III of Article 551 applies to generators that are mounted in or upon the RV; not separate units that may be on the ground away from the RV and connected to it by a cable. That conclusion comes from the terms and definitions used in Part III of Article 551.

Therefore, the code doesn't apply to the generator described in the original post. It would apply to the CABLE used to connect that generator to the RV, and the practices used to safely connect to that generator may be appropriate when such a generator is used.

Consequently, there is no requirement that a generator not mounted in or upon the RV be listed for use in an RV.

Where I quote the code and make comments, my comments are in italic.

551.1 Scope. The provisions of this article cover the electrical conductors and equipment other than low-voltage and automotive vehicle circuits or extensions thereof, installed within or on recreational vehicles, the conductors that connect recreational vehicles to a supply of electricity, and the installation of equipment and devices related to electrical installations within a recreational vehicle park. (A generator owned by an owner of a recreational vehicle, and set upon the ground some distance from the recreational vehicle, which may or may not be in a recreational vehicle park, is not an "electrical installation" and does not fall within any of the terms of the SCOPE of Article 551.)

551.30 Generator Installations (Note the term installations.)

(A) Mounting. Generators shall be mounted in such a way as to be effectively bonded to the recreational vehicle chassis. (Mounting implies in or upon; mounting doesn't mean sitting on the ground 50 ft away.)

(C) Installation of . . . . Storage batteries and internal-combustion-driven generators shall be secured in place . . . ("Secured in place" excludes generators not in or upon the RV.

14. Originally Posted by jwelectric
I would recommend that you have this done by a professional. It needs to be done internal of the generator such as this illustration shows.
[pic here]
Here the bond was removed because the “bonding” took place at the main for the building. The “bonding” can not occur at both the generator and the building.

NO! NO! NO! this is not the way to “bond” the generator and is doing nothing but causing a more dangerous situation.
Who would I get to check/change it for me so it can be done correctly? An electrician?

Originally Posted by jwelectric
In my area there is a slew of RV parks and I get calls all the time about someone using a generator that is not bonded and feeling a tingle on rainy days until I ask on the phone about the electrical connection before I go out on the call. 99% of these calls are about the remote generator that is not properly listed for the use and are not bonded.
Operating a generator that is exposed to rain sounds like a bad idea without even thinking about it.

I'm getting way off topic here but for some reason, our cable TV wires in the house here give off a mild shock on the outer part usually. The cable guy blamed the house's grounding. Sounds more like a grounding problem with the cable company's wires to me. I was having a problem with the internet constantly so a guy came out and was checking the connections and he got the shock twice. It is like, as you put it, a tingle. He blamed the ground problem with the house for the internet disconnecting constantly which was nonsense. It has worked fine before and since the constant disconnections for a couple years and the cable line still gives off a shock when you are trying to screw/unscrew connections. It doesn't do it as soon as you touch it. Its like you have to keep hold of it a while before the current builds up and gets back to you. He also tried to blame the wet ground outside yet the shocks happen in completely dry weather as well.

The part I like best is when it is still raining and the generator has been set inside a cavity of the RV to protect it from the weather. Now it just became a mounted generator and I recommend to the park manager to either have the RV owner sign a wavier of liability or evict then from the park.
Yeah, bad idea. Even if I wanted to do that (which I don't) my trailer only has one external compartment and the generator can't even fit into it so I can't possibly do it.

The NEC does not require that the generator being used on a RV be listed because the NEC is making a lot of money from the sale of listed generators but instead the NEC requires that generators be listed for the purpose as a safety issue.
The danger comes when the RV owner wants to save a little money and buy something just because it works without understanding the danger involved.
The NEC require proper RV-rated generators to ONLY be used vehicle-mounted compartments. It does not appear to say that you cannot use a portable generator for an RV anywhere in the NEC code as Bob pointed out:

Originally Posted by Bob NH
I believe that Part III of Article 551 applies to generators that are mounted in or upon the RV; not separate units that may be on the ground away from the RV and connected to it by a cable. That conclusion comes from the terms and definitions used in Part III of Article 551.
................
Consequently, there is no requirement that a generator not mounted in or upon the RV be listed for use in an RV.
................
(A) Mounting. Generators shall be mounted in such a way as to be effectively bonded to the recreational vehicle chassis. (Mounting implies in or upon; mounting doesn't mean sitting on the ground 50 ft away.)
This is exactly what I get from reading this section of the code.

15. I thought I'd post a follow-up to this thread.

I picked up the generator out of layaway today. The exact make/model of it is a Coleman Powermate Vantage PM0473505. Quite a nice generator. It seems to lack GFCI however but does have breakers with "reset" buttons. I can solve the GFCI issue with a plug-in GFCI adapter for about \$10 for the 15A outlets which I will be using only. It also has twistlocks in the form of 120V/30A as well as a 240V/20A. In addition it has 12V/15A out via a special plug-in cable with clamps at the end for battery (charging I suppose?).

I put some gas in it, checked the oil (full but should probably be replaced) and the air filter (not bad at all) and then attempted cranked it up. After fighting with it then realizing I had the kill switch on, I finally got it going and it worked fine.

Coleman lacks the manual on the website so I have emailed them requesting it.

There is a label on it saying that the neutral is floating so it's in fact not bonded to the frame. I took it to an electrician who is one of my brother's in-laws and he said that bonding neutral to ground won't do much of any good.

Near as we could figure due to the construction of the generator making it impossible easily access the electrical outlets to verify, the neutral is floating as the label on the generator says but the ground of the generator outlets is NOT bonded to the frame. There are rubber separators under the engine to isolate the engine from the frame and the engine has a "ground" (not "grounding") terminal for hooking up a rod.

So is it safe to leave the neutral floating as the generator was made and just bond that ground terminal on the engine to the frame of the generator like he said I could do?

Or do I need to take it to a generator repair shop and have them bond the neutral to ground and then bond the neutral/ground to the frame? They will have to remove the engine to even access the panel where the outlets are due to the construction of the unit.

I suggested to the electrician about using a plug-in GFCI adapter for extra safety and he said those are the most problematic piece of equipment there is and I guess basically said it won't do much to add safety and that it may just end up tripping all the time.

He said if I'm so concerned about safety I should just use a ground rod which I don't want to have to do since it's a portable, temporary use generator that is going to be moved from place to place all the time. But he more or less said it was fine to use any is.

Any opinions that say otherwise..?

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•