Grounding a generator?

[Number 4]

I've always boondocked with battery power only, but a Predator 3500 inverter generator is the cards so we can use the microwave and AC. When would the grounding element on the control panel be used, or do I just plug in the TT power cord after starting the generator and all is good? Question #2... do those of you who use external generators put them on the ground or do you use a platform of some kind to keep debris from getting sucked into the housing?

[wiredgeorge]

I have a 3500W (running watts) Champion generator that I have the wheel kit installed. This keeps it off the ground and they offer a cover that fits on the unit perfectly when not in use. My generator is dual fuel (propane/gas) and is electric start. It has a 30A RV plug so I can just plug into the thing and run it just like shore power. The generator 3 prong plug has a ground that grounds in the trailer somehow (never traced the ground). Since we have a 5th wheel with front bedroom, I keep the generator out in back (power cord is on back of trailer) and away from the trailer as far as possible. The generator is supposed to operate at 68dB but I think it is a tad louder than that. Carrying a platform would be a chore. They sell Champion generators on Amazon and at Tractor Supply.

https://www.championpowerequipment.c...uel-generator/

[deadeye]

If you use a ground fault detector on your trailer it will not work properly unless you use the ground. Use cant use a 12 inch spike with a 10 gauge wire pushed in the ground a a temporary measure. If the area is very dry you may need to wet it down.

[FlyingAroundRV]

A Predator 3500 is also on the cards for us. From the pix on HF website it looks like they come with wheels so keeping it off the ground shouldn't be a problem. I don't know if the wheels are lockable so a hard platform might not be such a good thing as the gen might vibrate off if the platform is not perfectly level.
As for grounding, I think as long as the ground of the trailer is connected to the ground of the gen, you're good to go. That ground is so that if anything shorts out to that ground it will tip a breaker or blow a fuse.
A time that you might want to drive a stake in the actual ground and ground like that is if you're camped under high voltage powerlines. There is a video on YT about a guy who was camped under some hi tension lines and was getting a shock every time he touched any metal on the trailer. He measured the induced voltage and it was around 148 volts from memory. In that situation, you'd definitely want an Earth ground to the rig.

[Number 4]

Thanks WiredGeorge for the info on your Champion. Ironically I sold one on behalf of my son on Craigslist last year and didn't buy it from him because compared to the Predator it's larger, heavier and emits more noise. I must admit the price is nice for the extra power.
Thanks Scott for the high voltage power line caution. That makes sense and thankfully we've never camped in close proximity to any constant buzzing that didn't have wings!
I didn't see anything about exterior grounding in the circuit panel documentation either, so it sounds like I'll be able to simply power up the gen and connect the TT.
If anyone else has input I'm listening!

[FlyingAroundRV]

Here's a situation where I think it would be a good thing to ground your gen and RV. With all the stray currents floating around, I wonder how the electronics in the RV and the gen would behave ...
https://youtu.be/iJ_XcAD_rSE

[bobbecky]

This is an excellent discussion on generator grounding and the need or not needing it. It also talks about the problem with an EMS rejecting power from a floating ground generator and how to safely overcome this. http://noshockzone.org/generator-gro...utral-bonding/

[skikrazee]

if you are referring to the ground screw on the bottom left of your picture that is for running 2 generators in parallel using a parallel kit, HF sells a 30 amp one but I have not seen their 50 amp one yet. Otherwise you just plug into the genny and you are good to go. you may need a 30 amp to 50amp (dog bone) adapter if you have 50 amp service on your rig that way you have A/C power to both sides of your breaker panel

[madmaxmutt]

Your generator should always be grounded, if it attached to some structure/trailer/vehicle. Not many people do it, but when you ARE the ground connection . . . You will know the meaning of path of least resistance. Been there, done that. Mostly overseas in not so nice places, but also in a rainy environment like SEA-TAC, you can easily have wet feet allowing current to flow when you touch the wrong thing.

https://www.osha.gov/OshDoc/data_Hur..._generator.pdf

I have never seen a generator without a ground lug. Ground lugs are for grounding. Connecting a parallel generator may use a ground, but it is NOT a ground.

[madmaxmutt]

Another reference is your owners manual.

"10. Do not operate the Generator before grounding.
The Generator must be earth-grounded
in accordance with all relevant electrical
codes and standards before operation."

[bobbecky]

Originally Posted by madmaxmutt

Your generator should always be grounded, if it attached to some structure/trailer/vehicle. Not many people do it, but when you ARE the ground connection . . . You will know the meaning of path of least resistance. Been there, done that. Mostly overseas in not so nice places, but also in a rainy environment like SEA-TAC, you can easily have wet feet allowing current to flow when you touch the wrong thing.

https://www.osha.gov/OshDoc/data_Hur..._generator.pdf

I have never seen a generator without a ground lug. Ground lugs are for grounding. Connecting a parallel generator may use a ground, but it is NOT a ground.

The referenced OSHA sheet says a ground is required if the generator is connected through a transfer switch, but does not say a grounding electrode is required if the generator is directly connected, such as when connected to the RV with the shore cable. A ground electrode is worthless if there isn't sufficient earth contact, so even a couple feet of a ground rod will do nothing. The NEC says this about ground electrodes:

NEC 250.5 Grounding and Bonding

Grounding and Bonding Electrodes include a metal underground water pipe in direct contact with earth for 10 feet or more, a metal frame of a building or structure, a concrete encased electrode or a ground ring

I am a retired electric utility lineman, and the requirement for grounding at a transformer on a pole required two 8 foot copper clad ground rods fully driven below grade level, and most municipal codes require at least the equivalent of the NEC. There is no way anyone is going to carry a number of ground rods out to the desert and be driving ground rods everywhere they set up camp. The best that can be done is to make sure all your electric connections are in perfect shape, that your plugs and receptacles on the shore cord are making good contact and the hot legs and neutral connections are not reversed. Your ground connection from the generator, through the cord, makes the ground connection to your RV, so there is no potential difference that would cause a hot skin condition.

[xrated]

+1 ^^^^^ what bobbecky said!

[Ddubya]

No need to ground a generator when hooked to a RV if you are not connected to shore power. Grounding a generator usually is in reference to using it as a backup to a homes electric feed.

[xrated]

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.

[madmaxmutt]

Originally Posted by bobbecky

The referenced OSHA sheet says a ground is required if the generator is connected through a transfer switch, but does not say a grounding electrode is required if the generator is directly connected, such as when connected to the RV with the shore cable. A ground electrode is worthless if there isn't sufficient earth contact, so even a couple feet of a ground rod will do nothing. The NEC says this about ground electrodes:

NEC 250.5 Grounding and Bonding

Grounding and Bonding Electrodes include a metal underground water pipe in direct contact with earth for 10 feet or more, a metal frame of a building or structure, a concrete encased electrode or a ground ring

I am a retired electric utility lineman, and the requirement for grounding at a transformer on a pole required two 8 foot copper clad ground rods fully driven below grade level, and most municipal codes require at least the equivalent of the NEC. There is no way anyone is going to carry a number of ground rods out to the desert and be driving ground rods everywhere they set up camp. The best that can be done is to make sure all your electric connections are in perfect shape, that your plugs and receptacles on the shore cord are making good contact and the hot legs and neutral connections are not reversed. Your ground connection from the generator, through the cord, makes the ground connection to your RV, so there is no potential difference that would cause a hot skin condition.

You skipped all of the paragraphs before the "if" statement that you are responding to. Which say the generator must be grounded if the devices it is powering are not directly attached to it. This is a published recommendation for austere conditions (ie use during or after a hurricane), which mimics a boon-docking scenario.

Ironically, most of these statements in owners manuals are put in to protect lineman. But, this isn't about an on-grid connection. I have spent most of my life making grounds where there were none. It can be done by many different field expedient methods in austere environments. It just takes work and as I stated, most people won't go to the trouble. I also stated that the OPs particular manual says it must be grounded.

[Number 4]

Originally Posted by Ddubya

No need to ground a generator when hooked to a RV if you are not connected to shore power. Grounding a generator usually is in reference to using it as a backup to a homes electric feed.

Thank you for the concise reply. My WFCO Ultra III Distribution Center (WF-9000 Series) panel has a transfer switch to "automatically transfer 120 Vac between two power sources (shore, generator)" and "protects the converter and other AC appliances from the unwanted initial voltage fluctuations."
I've not seen grounding in youtube videos that are testing the capability of generators, but I'm not fluent in "electrical". Better to ask a question that might be obvious to others. I understand it's an entirely different matter if I were to use the generator for home power in a blackout, to power multiple TT's or camping under high tension power lines ("hot skin" syndrome... wow!)

[tundrwd]

Isn't the ground for connecting two generators together? I'd think the cords would have the ground connected properly (30A, and grounded 15/20A).

I've got a Champion 2800/3100, and the manual specifically states that the ground on the panel is only used when connecting two units together to be sure they BOTH have the same ground.

[madmaxmutt]

Originally Posted by tundrwd

Isn't the ground for connecting two generators together? I'd think the cords would have the ground connected properly (30A, and grounded 15/20A).

I've got a Champion 2800/3100, and the manual specifically states that the ground on the panel is only used when connecting two units together to be sure they BOTH have the same ground.

I am not sure what model you have, but the Champion 2800/3100 manual I pulled up online says:
"Grounding
Your generator must be properly connected to an
appropriate ground to help prevent electric shock." and
"A ground terminal connected to the frame of the generator
has been provided on the power panel." in successive sentences.

[flybouy]

Originally Posted by Ddubya

No need to ground a generator when hooked to a RV if you are not connected to shore power. Grounding a generator usually is in reference to using it as a backup to a homes electric feed.

And electrically there is no difference. Think of it this way, your home electrical system is grounded and bonded usually via water pipe and grounding rod. When you plug in your camper to an outlet the supply to that outlet (your home) is earth grounded. Therefore, any short at the outlet will go to ground and not the user. When using a generator it replaces the house as a supply so where's the earth ground? There is none. There is the potential for a live animal or human to become that ground. Has that happened? Don't know but the potential is there.

[xrated]

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.