Community Forums

Barlow46 · 11-27-2012, 09:03 AM

One other scenario:

One of the problems with panel disconnects is that they are of the 2-pole variety, not 3-pole.
While it is true that they disconnect the two hot leads coming into the panel, they do not disconnect the neutral lead. There have been instances of power backfeeding into the neutral and since the neutral is directly connected to the outside feed, there can be a possible problem.

wa8yxm · 11-27-2012, 09:51 AM

Quote:

Originally Posted by CJ7ole

I am surprised that those of you with a 50 amp shore power plug in (which is 240 volts) do not have a genny that produces 240 volts. Are you sure?

Yes, I am 100% absolutly beyond even the faintest shadow of a doubt sure.

I measured it with my very own meters, a couple of different ones, I also read the owner's manual.

Onan RV generators are factory shipped set up for 120 volt.

I am told, and before that supected, that SOME generators can be re-wired for 120/240 volt service but have not (yet) done enough research to recommend for or against doing that.

But I am 100 percent sure my generator is 120 volt.

Barlow46 · 11-27-2012, 10:10 AM

10kw and 12.5kw onan quiet diesel is 120/240 wired.

CJ7ole · 11-27-2012, 10:22 AM

Quote:

Originally Posted by Barlow46

One other scenario:

One of the problems with panel disconnects is that they are of the 2-pole variety, not 3-pole.
While it is true that they disconnect the two hot leads coming into the panel, they do not disconnect the neutral lead. There have been instances of power backfeeding into the neutral and since the neutral is directly connected to the outside feed, there can be a possible problem.

Good point regarding the neutral, under certain scenarios it can energize.

Quote:

Originally Posted by wa8yxm

Yes, I am 100% absolutly beyond even the faintest shadow of a doubt sure.

I measured it with my very own meters, a couple of different ones, I also read the owner's manual.

Onan RV generators are factory shipped set up for 120 volt.

I am told, and before that supected, that SOME generators can be re-wired for 120/240 volt service but have not (yet) done enough research to recommend for or against doing that.

But I am 100 percent sure my generator is 120 volt.

Boy, am I eating crow on this thread! I pulled my owner's manual on my 7.0 KW Onan, and yes it produces 120 volts, in phase, on both legs even though pedestal power is most likely 240 volts. So backfeeding to the house and providing 120 volts on each leg of the panel it powers up the panel as if it were 240 volts except that if you measure voltage across both legs it should be zero volts, so you would be unable to run anything on 240, which I have never tried when hooked to the moho genny.

Well a day without learning is a day wasted.

hanko · 11-27-2012, 11:13 AM

Quote:

Originally Posted by CJ7ole

Not to belabor the point, but if the main is tripped (both legs) you will not backfeed the incoming powerlines. Now if you flip the breaker and one leg fails to trip, yes, you will backfeed the lines. I presume a transfer switch is fail safe in this regard. As is pulling the meter.

you are correct

Bug512 · 12-04-2012, 06:09 AM

Get a interlock kit. Here is one manufacturer. Also many of the panel manufactures make them. Link

Personally I had extra space in my motorhomes distribution panel to put a two pole 30 amp breaker. That connects to the house via a 10 AWG SOOW cord to my panel. This feeds two legs of 120/30 to my panel at home.

Here is another company that sells kits to do the same. Link

sailorbowman · 12-05-2012, 02:03 PM

Quote:

Originally Posted by Barlow46

One other scenario:

One of the problems with panel disconnects is that they are of the 2-pole variety, not 3-pole.
While it is true that they disconnect the two hot leads coming into the panel, they do not disconnect the neutral lead. There have been instances of power backfeeding into the neutral and since the neutral is directly connected to the outside feed, there can be a possible problem.

Nope, no way, and here is why. The neutral leg is connected directly to ground inside the breaker panel. It has the same electrical potential as ground. If there is a backfeed through the neutral then it's coming from the earth, and for practical discussion, that will not happen.