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Hopefully this adventure will be helpful to others as well. It's educational for me, for sure.

I got the bulb hooked up and it doesn't light up. There's some voltage reading across it, the volt meter jiggles around a bit but stays under 5. So it's not enough to light anything up.
With the bulb plugged in, line to ground reads 124 or so.
Without the bulb plugged, the ESP surge protector won't transmit current. With the bulb plugged in, it does. Presumably, the voltage on the neutral triggers something in the ESP and shuts it down.
So bonding the neutral does indeed straighten out the signal generation. The oscilloscope shows a much better looking signal than before. And it's filterable. Running it through the ESP gives a perfect looking signal that's actually better than the utility mains.

So it's probably very possible to set up two generators as the OP originally suggested, as long as the wiring and grounding can handle the completely unbalanced load.

My last question would be in the construction of a grounding plug. Is it better to wire up a dead short between the neutral and ground to bond the generator, or better to wire in a resistor in place of the incandescent bulb?
One last thing you might want to do with that o'scope just for grins. Look at the ac waveform when measuring between line and neutral. I suspect that it will be cleaner than between line and ground.

RE your last question: The reason I initially suggested testing with the light bulb was to limit the current from neutral to ground in case the Predator's output wasn't floating. It's clear now that it is. Neutral/ground bonding is supposed to be low impedance (low resistance) so a dead short is the norm.

BTW, if you tie the generator into the house wiring as the OP intends to do, the neutral ground bonding will occur within the house wiring, and no additional bonding will be necessary.
 

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Discussion Starter #62
This dialog has been VERY useful. bwswede, do you have the means to hook up your specific Hondas in parallel and take voltage measurements across all three pairs of outputs at the 30Amp receptacle?
I agree, the information provided in this post has been extremely useful. I have to admit though that I need to go back and study many of the posts as they are currently beyond my understanding of generators and electricity. Yes, I do have a way to make the measurements you describe but my generators are at my cabin which I won't be going to for several weeks.

I am very curious to know what the 120V (only) inverter generator manuals say about "neutral". I don't have any generators like this. Do they ever use that term? I'm looking at the pictures of bwswede's pair of hondas; the Companion says "Neutral floating" near the 30A outlet but I can't tell which slot, if either, is considered neutral. The 20A outlet looks like it has a slot that is hot and a slot that is neutral, but its not clear from the picture how/if they align with the two "hot" slots on the 30A outlet. Does the polarity implied by the slots on the standard 20A outlet really mean anything or is that just that just to accommodate a variety of plug types. (Do the two 20A outlets even have the same polarity?)
The owner's manual states the generator "has a system ground that connects generator frame components to ground terminals in the AC output receptacles. The system ground is not connected to the AC neutral wire."

A 30 amp RV outlet is 120 v. The two opposing angled slots are hot and neutral. The separate one is the ground.

Sorry to pose all these questions, bwswede. I do think its possible to accomplish what you are trying to do, but risky. I went through a similar thought process several months ago but got cold feet and bought an open frame 120/240 inverter gen for my house that didn't pose these challenges in the hook-up. I don't use anything 240 in my house except the AC, and I don't think my gen is really big enough to support AC without turning off some other important stuff. It was disappointing to sacrifice the additional quietness and flexibility of the smaller generators to get the hookup I do need along with the 240 I don't need, but I don't worry about getting smoked!
I am trying to do what you first wanted to do. I haven't got cold feet yet but they aren't exactly warm either. I need to do a lot more reading of the posts in this thread and from other Internet sources.

My understanding is that when the cables are plugged in and the generators are linked together they act as a single generator that happens to be powered by two engines. If I am correct then plugging this floating neutral generator into the house on both sides of the panel should be safe to do since everything is in the same phase. I am trying to think how is this different than what I have been doing forever with my old Coleman open frame generator plugged into one side of the panel. In that case all the 1/2 the neutrals are tied together and 1/2 the panel was powered up. In my proposed situation I want to add the other 1/2 of the panel which would simply add more neutrals to the already tied together neutrals. If I am missing some important point I hope someone will let me know.

Thank you for all for the very helpful discussion. I need to dig deeper into some of the posts. Especially ones speaking about 60v. Those comments have me confused.

Blane
 

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[QUOTE="bwswede, post: 77482, member: 379.
I am trying to think how is this different than what I have been doing forever with my old Coleman open frame generator plugged into one side of the panel. In that case all the 1/2 the neutrals are tied together and 1/2 the panel was powered up. In my proposed situation I want to add the other 1/2 of the panel which would simply add more neutrals to the already tied together neutrals. If I am missing some important point I hope someone will let me know.

Blane
[/QUOTE]
Blane. The good news is I think the real tech guys on this thread are now thinking that the measurement of two hot 60V legs is just a ghost phenomenon and can be ignored. (Guys; correct me if I didn't sum that up correctly.) The generator really does have one 120 hot and one neutral. And it sounds like your manual confirms you have a neutral and a hot, and tells you which one is which on the 30A outlet. So no need to be concerned about sending rogue voltages up the utility neutral wire. You could approach this like you did on your "half" solution with your coleman, except for a couple things.

1. First, when you connected your coleman to 1/2 the circuits via one of the two hot sides of the panel, you actually could have gone ahead and connected BOTH hot sides of the panel to the one hot wire from the generator, and lit up the whole panel with 120. That is what you would basically need to do with the new generators, except that ...

2. ... you will not treat the two sides like they are separate halves. Even though you have two generators, you can't make them supply two halves independently. You should think of it as super-sizing one generator; and using that one source to light both sides of the panel through the companion parallel stuff you got with the pair of generators.

3. I am willing to bet that your panel neutrals are NOT set up 1/2 and 1/2 like the hot wires are. The neutrals are all the same. When you connected your coleman neutral I believe to really connected it to all the neutrals, not just half.

4. If you don't have any 240V circuits, this method doesn't restrict you at all. But if you do have 240V circuits they must be turned off. At best, they won't work and at worst its a short circuit fire hazard. I am not savvy enough to know exactly what will happen but I think the main risk you have is firing up the generator and forgetting to turn off any 240 circuits then melting you new generators or burning the place down. I hope some other folks can comment on this.

5. It would be great if you can get an interlock for your panel to prevent the possibility of cross connecting generator and utility power. There is no way to make this code legal without $$$ and electricians. But at least you need to be aware of the possible risks, how to reduce them, and hope you caught them all. I know some, but not all.
 

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I have a 3000 watt 120 volt Honda EU3000ISAG powering both legs of my electrical panel.
I use an L5-30P Male to L14-30R female adapter connected to the generator that has an integrated jumper connecting the two hot leads (X & Y prongs) on the output side of the adapter. This feeds both legs of my electrical panel with 120 volts. I am connecting through an interlock kit. I make sure that I turn off my 240 volt breakers and keep them off with this setup. I can run my while house with this setup minus my AC and range. (I have a gas dryer.) I have to limit high power devices, such as my microwave, to one at a time to avoid overdrawing my generator.
Here is the link for the adapter I am using: https://www.amazon.com/dp/B01MDJYFDI/ref=cm_sw_r_cp_apa_fabc_S3W9FbAJHQ24T?_encoding=UTF8&psc=1
 

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I have a 3000 watt 120 volt Honda EU3000ISAG powering both legs of my electrical panel.
I use an L5-30P Male to L14-30R female adapter connected to the generator that has an integrated jumper connecting the two hot leads (X & Y prongs) on the output side of the adapter. This feeds both legs of my electrical panel with 120 volts. I am connecting through an interlock kit. I make sure that I turn off my 240 volt breakers and keep them off with this setup. I can run my while house with this setup minus my AC and range. (I have a gas dryer.) I have to limit high power devices, such as my microwave, to one at a time to avoid overdrawing my generator.
Here is the link for the adapter I am using: https://www.amazon.com/dp/B01MDJYFDI/ref=cm_sw_r_cp_apa_fabc_S3W9FbAJHQ24T?_encoding=UTF8&psc=1
Yes, that plug looks like what you need if you are using a standard L14-30 120/240v 30 Amp inlet box on the house. That plug is better than a homemade jumper; if I was going to use 120 on both hots of the house, that's how I would do it. I'm not optimistic that this would pass muster with a building inspector, though. (And that plug doesn't show any UL type markings). On my panel, it is possible to buy little "locks" to prevent individual breakers from being turned on or off. I would consider getting them for the 240V breakers even though you are aware that they must be off. Accidents happen. (I turn all the breakers off individually and flip them back one by one after the generator has been powered up and connected to the panel. I could see myself losing track of where the 240 breakers are while doing this in partial darkness in the basement, then flipping one on by mistake).
 

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Yes, that plug looks like what you need if you are using a standard L14-30 120/240v 30 Amp inlet box on the house. That plug is better than a homemade jumper; if I was going to use 120 on both hots of the house, that's how I would do it. I'm not optimistic that this would pass muster with a building inspector, though. (And that plug doesn't show any UL type markings). On my panel, it is possible to buy little "locks" to prevent individual breakers from being turned on or off. I would consider getting them for the 240V breakers even though you are aware that they must be off. Accidents happen. (I turn all the breakers off individually and flip them back one by one after the generator has been powered up and connected to the panel. I could see myself losing track of where the 240 breakers are while doing this in partial darkness in the basement, then flipping one on by mistake).
I received the blessing of the electrician I hired to install my generator inlet and reviewed with him how I would be using my generator with the adapter mentioned in my above post. Moreover, if I were to have any kind of home inspection in the future, the generator would not be hooked up at that time of the inspection.
The lockouts are not a bad idea for preventing accidental use of the 240 volt circuits. My wife and I are comfortable with bright sticker labels we placed on those circuits as a reminder to keep them de-energized when running off generator power. I think you could run into human error with the lockouts as well by forgetting to place them on the 240 volt circuits when using the generator. We also have a laminated checklist we run through to help prevent human error.
We also turn off all circuits and activate them one at a time when first running on generator power to avoid inrush current overdrawing the generator.
 

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We also have a laminated checklist we run through to help prevent human error.
I'm impressed! Sure beats my handwritten notes on the back on an envelope tucked between cables coming out the top of the panel.

Here's the lockouts I use; its a lockon in my case so I don't accidentally turn off the dedicated circuit for the wired-in smoke detectors.
Square D by Schneider Electric HLO1CP Circuit Breaker Handle Lock Off Kit - - Amazon.com

BTW. I really don't know if its necessary to lock out the 240V circuits. If they are not locked out you would just be applying the same 120 voltage potential to both sides of the load which wouldn't cause any current to flow; or so I think. But why take a chance.
 

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I think you could run into human error with the lockouts as well by forgetting to place them on the 240 volt circuits
Depending on the number of 240V breakers, you could place them all together at the top on the left or right side of the breaker panel, below the interlocked inlet breaker. That way they're all easy to isolate/remember.
 

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BTW. I really don't know if its necessary to lock out the 240V circuits. If they are not locked out you would just be applying the same 120 voltage potential to both sides of the load which wouldn't cause any current to flow; or so I think. But why take a chance.
They would both be in phase, though, not out of phase by 180 degrees like they're supposed to be. The items in a 240V appliance that only use 120V from one leg would likely be OK (for example the circuit boards and light bulbs in a range), but if someone tried to energize a 240V widget like a burner, the outcome MIGHT depend on how the device is wired internally. I would like to think that the bridged 120V legs would do nothing, but some things might try to come on with 120V to neutral/ground?
 
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or you could do a sub panel for the 240 or the 120 vac stuff....
then do the inter lock on that panel.

most folks do a gen items sub panel with an interlock.

most electric stoves have split voltage on the burners..
for low settings they use 120 vac....
at least on the ones I have.
not all brands are wired the same.
 

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or you could do a sub panel for the 240 or the 120 vac stuff....
then do the inter lock on that panel.

most folks do a gen items sub panel with an interlock.

most electric stoves have split voltage on the burners..
for low settings they use 120 vac....
at least on the ones I have.
not all brands are wired the same.
Wow. How do those split voltage stoves get wired at the panel? Are there two breakers?
 

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Wow. How do those split voltage stoves get wired at the panel? Are there two breakers?
The stove is wired to 240V using two hot wires (one hot from one 120V side of the electrical panel and the other hot from the other 120V side of the electrical panel). There is also a Ground wire and a Neutral wire connected to the stove.
Any 120V function of the stove will only be powered thru one hot wire, the Ground, and Common wires.
This provides the 120V. The other hot wire is not in that 120V circuit.
 

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yea they run as 120 / 120 and 240 inside the stove assy's.
at least on some brands.
so for the low burner setting it can be 120 vac.
now on new glass top units and induction units most are computer controlled heat.
and are 240.
look up the wiring diagram for your exact make and model of stove.
or look on the rear of the stove or under the top.
they used to place the wiring diagram there.
 

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Thanks guys for explaining this 120/240 circuit stuff. I don't have any three wire 240V loads like a stove in my panel; only a two wire 240V air cond. compressor circuit with a breaker like the one I linked. I didn't understand how a 240 breaker works; I was thinking it was basically one fuse limiting the combined current running through both hots but it seems like it is two fuses measuring each hot side independently but tripping together. Even though my AC compressor breaker has what looks like a single handle, I think it may still be a double internally like the one in Old Man's link. Maybe I will try to figure this out with a meter. (I was surprised that I couldn't easily find a simplified diagram of how a circuit breaker works)!
 
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