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Old 05-05-2018, 01:21 PM   #21
madmaxmutt
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In a generator setup you will have (for the 30 amp supply type trailers) one hot, one neutral and one ground lead. That connection from the generator is via a 3 pole receptacle and your wire/cable that plugs into the side of your RV will have a place for the same three wires....one hot, one neutral, and one ground wire. In other words, the ground is carried all the way from the source (the generator) all the way to the breaker panel in the RV.
Where is this ground that you speak of? A standard Honda inverter style generator is not grounded. I don't even believe they are bonded. The OP is talking about boon-docking. No grid, no lines, no nothing but a standalone ungrounded generator is what that would mean to me.
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Old 05-05-2018, 02:58 PM   #22
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And again.....from my previous post on page one.......

Another short (cliff notes if you will) read from Mike Sokol.......

So the bottom line is this. If you don’t have an EMS in your RV, then you can use either a bonded or non-bonded neutral generator. If you DO have an EMS installed, then you’ll want to use a bonded neutral generator. And the easiest way to neutral bond something like a Honda generator is using the Generator Neutral Bonding plug available from Progressive Industries, or you can wire it yourself from my articles on No~Shock~Zone.

I do believe that any RV that plugs into unknown pedestal power (don’t we all) should have some sort of EMS protection. Note that this EMS product is more than a mere “surge-strip” to prevent electrical spikes from entering your system. A proper Electrical Management System will not only protect you from lost grounds, it will also shut down the AC power going to the RV if it goes over or under voltage. Accidentally connecting your RV to a TT-30 pedestal receptacle that’s been miswired for 240-volts instead of 120 volts is a very expensive mistake.
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Old 05-05-2018, 03:32 PM   #23
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The difference is that the utility company brings in three wires to your house...
Two separate 120V legs and one neutral wire. At the service entrance, in the breaker box, the neutral and the ground wire are bonded. The ground wire that is in your breaker box comes from an a wire that was added in there and the other end of it is attached to the ground rod at the service entrance point.....usually outside of your house and within close proximity to the meter.

In a generator setup you will have (for the 30 amp supply type trailers) one hot, one neutral and one ground lead. That connection from the generator is via a 3 pole receptacle and your wire/cable that plugs into the side of your RV will have a place for the same three wires....one hot, one neutral, and one ground wire. In other words, the ground is carried all the way from the source (the generator) all the way to the breaker panel in the RV.

A 240 volt system (50 amp RV service) will have basically the same thing except that in that type system, you will have one 120V hot wire, a second 120V hot wire that is 180 degrees out of phase with the first 120V wire, then you'll have a neutral wire, and finally you will have a ground wire.....so four total. And again, at the voltage source (the generator), there will be a 4 pole receptacle for you to plug into and that cable will have 4 wires within it....two 120V leads that are 180 degrees out of phase with each other, a neutral, and a ground. So once again, the ground lead is carried all the way from the source (the generator) and goes all the way to the breaker panel. And there is your difference between a generator supply and the power coming into your house. And just so you know, on the house side of the discussion, the ground rod that is driven at your service entrance is put there because at the pole where the transformer is or at the pad, if its a ground mounted transformer, there will be a ground rod driven there also and the the ground connection of the transformer will be attached to it.
Thank you for that in-depth explanation. I do understand how it works, I was adjunct faculty for many years teaching several electrical courses. Read your post and tell me where I erred in stating that using a genset as you described has an earth ground.
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Old 05-05-2018, 04:13 PM   #24
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And again.....from my previous post on page one.......

So, you don't have an answer except to quote a guy with a website? OSHA says otherwise.
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Old 05-05-2018, 05:37 PM   #25
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Sure I have an answer. The reason for a ground rod in a residential service is to supply a ground path back to the source, which is the utility's pole or pad mounted transformer for your house. The utility does not supply four wires coming to your house, as I explained earlier.....they supply a neutral and two 120V legs that are 180 degrees out of phase with each other. So, by driving a ground rod at the house and the utility grounding the transformer at the proper place, the earth is the "conductor" for ground, between the ground rods...the one at the house and the one at the pole.

With a generator supplying the power (also known as the source), and the fact that the generator outlet plug provides a ground circuit, whether it's a 3 wire system that is typically 30 amps, or it's a 4 wire system which is typically 50 amps....a ground conductor is supplied and doesn't need to rely on rods being driven into the ground on both ends.....the source (generator) and whatever is being supplied (the RV or camper).

If the utility company provided a 4 wire drop from the pole or pad transformer, it would have a dedicated ground wire in the 4 wire configuration.......but they don't, they use a ground rod at the pole/pad and then have to provide a ground rod at the service entrance and run that wire up and into the breaker panel.....where the ground and the neutral are bonded.

And on somewhat of a side note to madmaxmutt......OSHA does not have jurisdiction for residential power distribution and residential power.....that is directed/governed/enforced by the NEC.
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Old 05-05-2018, 05:59 PM   #26
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Sure I have an answer. The reason for a ground rod in a residential service is to supply a ground path back to the source, which is the utility's pole or pad mounted transformer for your house. The utility does not supply four wires coming to your house, as I explained earlier.....they supply a neutral and two 120V legs that are 180 degrees out of phase with each other. So, by driving a ground rod at the house and the utility grounding the transformer at the proper place, the earth is the "conductor" for ground, between the ground rods...the one at the house and the one at the pole.

With a generator supplying the power (also known as the source), and the fact that the generator outlet plug provides a ground circuit, whether it's a 3 wire system that is typically 30 amps, or it's a 4 wire system which is typically 50 amps....a ground conductor is supplied and doesn't need to rely on rods being driven into the ground on both ends.....the source (generator) and whatever is being supplied (the RV or camper).

If the utility company provided a 4 wire drop from the pole or pad transformer, it would have a dedicated ground wire in the 4 wire configuration.......but they don't, they use a ground rod at the pole/pad and then have to provide a ground rod at the service entrance and run that wire up and into the breaker panel.....where the ground and the neutral are bonded.

And on somewhat of a side note to madmaxmutt......OSHA does not have jurisdiction for residential power distribution and residential power.....that is directed/governed/enforced by the NEC.
If the NEC has a specific statement covering a standalone generator attached to a trailer without connection to any electrical grid, could you post that source? I would truly like to read where the NEC says, don't ground a generator.
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Old 05-05-2018, 06:10 PM   #27
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702.11 Portable Generator Grounding. (A) Separately Derived System. Where a portable optional standby source is used as a separately derived system, it shall be grounded to a grounding electrode in accordance with 250.30. See related UL

(B) Nonseparately Derived System. Where a portable optional standby source is used as a nonseparately derived system, the equipment grounding conductor shall be bonded to the system grounding electrode. See related UL

By the way, we are talking about A, not B. And, this still isn't exactly a boon-docking situation.
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Old 05-05-2018, 06:43 PM   #28
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I believe that a portable generator supplying an RV would be considered a NON separately derived system, and the reason is that the generator provides a path of ground from the source, to the generator receptacle, through the plug and cable, and to the plug on the opposite end.....which is then plugged into your RV.
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Old 05-05-2018, 06:43 PM   #29
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Sure I have an answer. The reason for a ground rod in a residential service is to supply a ground path back to the source, which is the utility's pole or pad mounted transformer for your house. The utility does not supply four wires coming to your house, as I explained earlier.....they supply a neutral and two 120V legs that are 180 degrees out of phase with each other. So, by driving a ground rod at the house and the utility grounding the transformer at the proper place, the earth is the "conductor" for ground, between the ground rods...the one at the house and the one at the pole.

With a generator supplying the power (also known as the source), and the fact that the generator outlet plug provides a ground circuit, whether it's a 3 wire system that is typically 30 amps, or it's a 4 wire system which is typically 50 amps....a ground conductor is supplied and doesn't need to rely on rods being driven into the ground on both ends.....the source (generator) and whatever is being supplied (the RV or camper).

If the utility company provided a 4 wire drop from the pole or pad transformer, it would have a dedicated ground wire in the 4 wire configuration.......but they don't, they use a ground rod at the pole/pad and then have to provide a ground rod at the service entrance and run that wire up and into the breaker panel.....where the ground and the neutral are bonded.

And on somewhat of a side note to madmaxmutt......OSHA does not have jurisdiction for residential power distribution and residential power.....that is directed/governed/enforced by the NEC.
The "source" from the utility company is earth grounded, the "source" from a generator setting on the ground is not. I'm not debating that a boondocker isn't going to properly ground a generator. What I stated was that with it not properly being properly earth grounded that the POTENTIAL exists for electrocution if a failure occurs. Why is the neutral and ground bonded in your power distribution panel in your house? It's done so that if the neutral is lost the human doesn't become a component in the circuit . As long as the human has a higher resistance than the earth ground the current takes the path of least resistance to the earth ground. It's a safety feature, not a necessity to make the circuit operational.
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Old 05-05-2018, 06:52 PM   #30
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As a return side note . . .NEC isn't jurisdiction, nor is a government entity that has jurisdiction. It is a code. The 590.6 section is the closest thing that exists to a boondocking scenario, because the code doesn't take boondocking into account. That section doesn't talk about grounding, but focuses on GFCIs.
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Old 05-05-2018, 06:57 PM   #31
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The "source" from the utility company is earth grounded, the "source" from a generator setting on the ground is not. I'm not debating that a boondocker isn't going to properly ground a generator. What I stated was that with it not properly being properly earth grounded that the POTENTIAL exists for electrocution if a failure occurs. Why is the neutral and ground bonded in your power distribution panel in your house? It's done so that if the neutral is lost the human doesn't become a component in the circuit . As long as the human has a higher resistance than the earth ground the current takes the path of least resistance to the earth ground. It's a safety feature, not a necessity to make the circuit operational.
The whole point is that the utility companies DO NOT provide a separate ground conductor from their pole mounted transformer to your house....they use a ground rod driven into the ground and then you the house end, there is another ground rod driven and a wire from that to the service panel or breaker panel.....where the neutral and the earth ground is bonded. The earth ground system, via ground rods and dirt or earth then effectively becomes a ground "conductor" between the utility source of power and your house.

When a portable generator is used for providing power to an RV, the generator (source) has a ground via the generator receptacle, the plug and cable that plugs into the generator, and then the plug on the other end that goes into the RV....so there is no need for an earth ground path when the generator to the RV has a dedicated ground wire.
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Old 05-05-2018, 07:39 PM   #32
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I believe that a portable generator supplying an RV would be considered a NON separately derived system, and the reason is that the generator provides a path of ground from the source, to the generator receptacle, through the plug and cable, and to the plug on the opposite end.....which is then plugged into your RV.
Looks separate to me.


Doesn't what you described just make it a common with no ground at all?
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Old 05-05-2018, 10:29 PM   #33
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When you are on that page that you listed ^^^^ scroll on down one more picture and check that out.
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Old 05-06-2018, 05:04 AM   #34
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When you are on that page that you listed ^^^^ scroll on down one more picture and check that out.
OK. Notice in each picture on that page, there is an earth ground depicted.
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Old 05-06-2018, 05:13 AM   #35
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And you will notice in the third pic, the generator is NOT earth grounded with a ground rod. That is because the generator case/frame is connected to the transfer switch via the ground wire circuit in the generator plug, then through the cable, and on over to the transfer switch, and then over to the service or shore power part of it.....which is obviously not in use, but the ground and neutral is not switched anywhere along the line....so the ground rod at the shore power connection and the continuous run all the way back to the generator provides the earth ground without driving a ground rod at the generator.
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Old 05-06-2018, 05:42 AM   #36
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Assuming every Keystone trailer come equipped from the factory with a transfer switch . . . There is no earth ground coming from a service on the other side of the transfer switch. So, it really doesn't fit that scenario.


Further down the page, it states a neutral grounded generator can only be used with a transfer switch or as a stand alone (which I assert is the closest to a boondocking scenario) "and then ground rods are required".
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Old 05-08-2018, 08:39 AM   #37
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Ok - had to dredge memory, and have found a few linkies.

Regarding the link: https://www.osha.gov/OshDoc/data_Hur..._generator.pdf

Section "Grounding Requirements for Portable and Vehicle Mounted Generators"
Under the following conditions, OSHA directs (29 CFR 1926.404(f)(3)(i)) that the frame of a portable generator need not be grounded (connected to earth) and that the frame may serve as the ground (in place of the earth):
• The generator supplies only equipment mounted on the generator and/or cord and plug-connected equipment through receptacles mounted on the generator, § 1926.404(f)(3)(i)(A), and
• The noncurrent-carrying metal parts of equipment (such as the fuel tank, the internal combustion engine, and the generator’s housing) are bonded to the generator frame, and the equipment grounding conductor terminals (of the power receptacles that are a part of [mounted on] the generator) are bonded to the generator frame, § 1926.404(f)(3)(i)(B).
Thus, rather than connect to a grounding electrode system, such as a driven ground rod, the generator’s frame replaces the grounding electrode.

For an explanation - see http://rvtravel.com/how-generator-ne...r-an-rv-works/

Also see http://www.rvforum.net/SMF_forum/ind...?topic=86203.0

you can prowl around at the above site for more info...
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Old 05-08-2018, 09:02 AM   #38
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Really, all these pages of Grounded v. Non-grounded, bonded v. non-bonded, and nothing about risking your trailer electrical system to a POS Harbor FRIGHT generator made by the great people of CHINA??? Last summer I had to watch in fear as my adjacent neighbor's China Genny went up in flames 40 feet from my own rig! Good luck to all that choose the cheapest route!
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Old 05-08-2018, 10:03 AM   #39
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I guess I'm a slow learner, or maybe they were all I could afford at the time, but I went through 3 Chinese generators before I bought my Yamaha 6300 Inverter generator.
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Old 05-08-2018, 04:59 PM   #40
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Ok - had to dredge memory, and have found a few linkies.

Regarding the link: https://www.osha.gov/OshDoc/data_Hur..._generator.pdf

Section "Grounding Requirements for Portable and Vehicle Mounted Generators"
Under the following conditions, OSHA directs (29 CFR 1926.404(f)(3)(i)) that the frame of a portable generator need not be grounded (connected to earth) and that the frame may serve as the ground (in place of the earth):
• The generator supplies only equipment mounted on the generator and/or cord and plug-connected equipment through receptacles mounted on the generator, § 1926.404(f)(3)(i)(A), and
• The noncurrent-carrying metal parts of equipment (such as the fuel tank, the internal combustion engine, and the generator’s housing) are bonded to the generator frame, and the equipment grounding conductor terminals (of the power receptacles that are a part of [mounted on] the generator) are bonded to the generator frame, § 1926.404(f)(3)(i)(B).
Thus, rather than connect to a grounding electrode system, such as a driven ground rod, the generator’s frame replaces the grounding electrode.

For an explanation - see http://rvtravel.com/how-generator-ne...r-an-rv-works/

Also see http://www.rvforum.net/SMF_forum/ind...?topic=86203.0

you can prowl around at the above site for more info...
Even though X already pointed out that OSHA isn't the authority for a boondocking RV camper, (not that there is one at all) the OSHA link is what I originally posted pages ago.

Assuming para B is met by the generator in question, para A is not met. Once you tie into a trailer, your AC, toaster and microwave are not cord and plug connected to the receptacles on the generator. The are connected via series of electrical connections and devices.

A paragraph from the source earlier in the document.
"Do not connect a generator to a structure
unless the generator has a properly
installed transfer switch."
Most people with trailers won't do this, drive ground rod or care less about it.
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