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Discussion Starter #22
An excellent point

you could overload a MWBC neutral by using a 120v generator the way you described.
Great point. I recall now researching this back when I first posted this. If I remember the conversation right with the local guy each of my breakers/circuits has a dedicated neutral. None are shared, again assuming my memory is good.

I do appreciate your comments. Trying to find the best solution without compromising safety.
 

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E2 Electrician
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Great point. I recall now researching this back when I first posted this. If I remember the conversation right with the local guy each of my breakers/circuits has a dedicated neutral. None are shared, again assuming my memory is good.

I do appreciate your comments. Trying to find the best solution without compromising safety.
The only way is the right way... :)
 

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Discussion Starter #24
True, but is there a solution?

The only way is the right way... :)
I cannot philosophically disagree. But, is there a way to use a smaller, much more fuel efficient generator on an existing panel? Can't store enough fuel to the big one for nearly as long as the small one.

Seems silly to have the correctly installed gentran panel, all wiring done right and then bypass it all by using extension cords for the fridge & lights when using the small generator.

Is there a different or better way? Must I always use the big, gas sucking generator even when all I want is the fridge & a light or 2? There has to be a better way......
 

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Discussion Starter #25
Fixed genny?

Nah. Imma just do it right and get a fixed position genny. But good to know. AND a bigger panel.
Can't see spending many thousands for a fixed backup, especially since we have no gas/propane. Its gasoline or nothing for a generator, unfortunately. Besides, I already own two Honda inverters which I can take with me if I move.

I am puzzled on why one would need a "bigger panel", however. If I have a properly sized panel, proper back up gentran box & correct wiring why would I need a bigger panel? I'm not trying to skirt things by backfeeding or something equally dangerous. Just want to at times use the back up panel with a smaller, more fuel efficient generator.
 

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E2 Electrician
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I cannot philosophically disagree. But, is there a way to use a smaller, much more fuel efficient generator on an existing panel? Can't store enough fuel to the big one for nearly as long as the small one.

Seems silly to have the correctly installed gentran panel, all wiring done right and then bypass it all by using extension cords for the fridge & lights when using the small generator.

Is there a different or better way? Must I always use the big, gas sucking generator even when all I want is the fridge & a light or 2? There has to be a better way......
I would pick a setup for whatever generator you want to use and stick to it.
 

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Discussion Starter #27
I started with the 6500

I would pick a setup for whatever generator you want to use and stick to it.
All was set up for the 6500W unit and then I experienced how much fuel it could use, even on the ECO setting & as an inherently more efficient inverter. Realized that 90% of my needs could be met with a 2000x unit so long as I had the bigger one for the well, hot water & furnace. With a wood stove even the furnace circuit is seldom used.

At 1/3 the fuel consumption the smaller one has a certain appeal, even though totally unusable when one needs higher amounts of power. Don't want to compromise safety and am puzzled why the gentran people, Honda & local electrician all had no issue provided I use it as described. Yours is the first substantive concern I've seen, hence my alarm. Of course, all this talk on the TV about power outages got me thinking!

I wish the panel could be designed to accommodate everything!
 

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Discussion Starter #28
update

Update: while I philosophically dislike mwbc circuits, I do have some. I've scheduled a trusted electrician to come by and inspect/change my panel as needed. Gentran makes NO mention of watching out for mwbc circuits in the install instructions. Still undetermined is if I moved only half or both sides of any mwbc circuits & if such is an issue under either line power and/or gen power.

I am annoyed. All this BS because the original electrician took the easy path. Yes, i know mwbcs are common, but I still do not like the idea.
 

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Discussion Starter #29
Additional update: Had the setup inspected

To allay any concerns, I had the gentian panel & wiring, etc. inspected by a local licensed electrician. He acknowledged that there are indeed some MWBCs in the box and which are hooked up to the gentran panel. We also discussed my desire to use a 3 to 4 wire cable adaptor for circumstances where the larger, much less fuel efficient generator isn't needed and the concerns expressed here by some.

In short, he agreed that those concerned with an overload of a MWBC are theoretically correct, but given the maximum 16A output of the smaller Honda generator (13.7 continuous) there is little, if any, real world risk of an overloaded neutral even under worst case scenarios. Were one to connect a much higher output generator with a 3 to 4 wire adapter & run crazy loads on those circuits sharing a neutral an overload could be a risk. Since I have no intent of doing such, nor do I even own a 3 wire generator capable of such high output all should be, or so I hope, fine.

Thanks to all for the comments & discussion.
 

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You dont even know the dangers of this....
There really are none :thumbsup:

Im a professional, not sure what else to tell you about that setup.
I'm a professional too, or at least a licensed electrical contractor :thumbup:

The setup that he described is perfectly normal and commonly used. I do it myself.

you could overload a MWBC neutral by using a 120v generator the way you described.
Impossible. The generator is only capable of delivery 2,000w (16.6A) for a short period of time. The generator is simply not able to overload the neutral of a MWBC.

The only way is the right way... :)
There is nothing wrong with this way. I understand that it seems wrong on the surface, especially to an electrician, but it's not.

I would pick a setup for whatever generator you want to use and stick to it.
Again, I have to disagree. I do pretty much exactly what the OP does, I run a Honda EU2000i full time and only connect my large generator when I need water or heat. This system worked well for me for over 12 days last month, and many other people.
 

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Discussion Starter #31 (Edited)
Thanks, Macken, for the comments.

Macken,

I appreciate your comments & taking the time to do a detailed response. The fact that it didn't talk down to me as I've had in the past is also appreciated. I'm here to learn, not be right! I learned about MWBCs in this thread and have taken steps to remedy any mistakes. For this a appeciate the time & efforts of all those who posted. The last thing I want to do is fry the family.

I'm even going farther than the electrician suggested & double checking that whatever circuits I have on the Left lug are on the A gentran lug and those on the Right lug are on the B side. This is to ensure that any circuits routed through the gentran panel maintain MWBC polarity for when I do use the larger EU6500. There is one minor lighting circuit that on second look may not work out due to an insufficient number of B side breakers, so I may remove it. I called the electrician back on this who sees no real world issues, but I like to be safe.

Your analysis matches mine. I do see where the other pros here are coming from & agree that there would be a danger with a larger generator. There is NO WAY I'd put 40 amps through a 3 to 4 wire adapter set up. As a result of this thread I've cancelled plans to purchase a second EU2000, which I had toyed with using in dual synch mode for 27.4A (3200W) continuous / 33.2A (4000W) surge output. That's too much, which I won't risk.

Glad to see your EU2000 worked out so well. I've only needed mine once "for real" and noted a drastic cut in fuel use over the already very efficient for its size EU6500 I also own. You used yours for 12 days. At 18 hours use per day that's about 2 gallons. To do the same with the 6500, never mind the gas guzzling "standard" gen sets and we're talking 6 gallons, a 3 fold increase. A cheaper "standard" gen set would use perhaps 12 gallons per day or more! Over 12 days thats a lot. Again, it isn't the fuel use & cost that concerns me, but availability. In most outages gas stations also shut down or, if the outage lasts long enough and as we've seen on the news, run out of gas. The only times I might need the bigger generator is when running the well, microwave and/or heat. But, I have a fireplace, which generally heats the house down to about 35. Below that the heat will tend to come on.

Got to be a fan of these inverter Hondas. Way quieter and more efficient than anything else out there, although I hear the Yamahas are good too. Just harder to get parts for them, which is why I went with Honda.
 
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