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Inverters => MN15-12KW-AIO => Topic started by: ASword on March 12, 2025, 01:05:13 PM

Title: Single phase 240v generator compatible?
Post by: ASword on March 12, 2025, 01:05:13 PM
I recently noticed that some inverters require 120/240v split phase output from a generator.  The MidNite AIO doesn't seem to explicitly state this, and the generator connection point appears to have only 2 wires, but best not to make assumptions... so is it compatible with a 120/240vac single phase generator?
Title: Re: Single phase 240v generator compatible?
Post by: DarkForestSolar on March 12, 2025, 01:28:11 PM
I am not sure...

By definition a 120/240 generator has three wires -- otherwise there's no way to get the 120 volts from it.  But if you are talking about a 240 volt single phase generator with only two hots and no neutral (or a EU spec one with a hot and a nuetral 230 volts apart), I am not sure what the ONE would make of that.
Title: Re: Single phase 240v generator compatible?
Post by: ASword on March 12, 2025, 01:55:03 PM
Yes, and the generator (and its manual) have line/neutra/ground wires.  Plus, my house with all of its 120v circuits, works fine.  So I'm a bit confused by what they mean in the manual when it says its single phase 120/240vac.
Title: Re: Single phase 240v generator compatible?
Post by: ClassicCrazy on March 12, 2025, 08:34:03 PM
Here is one answer to the question of differences between single and split phase
https://www.prostarsolar.net/article/is-split-phase-the-same-as-single-phase.html
Larry
Title: Re: Single phase 240v generator compatible?
Post by: ASword on March 12, 2025, 09:39:45 PM
Thanks for the link.  Unfortunately it just leaves me confused again.  This seems to imply that houses are wired single phase (with 3-wire connections), and that matches my generator (which makes sense)... but that throws into question the "other" inverter's requirement that a generator must output 240v split phase. 
Title: Re: Single phase 240v generator compatible?
Post by: ClassicCrazy on March 12, 2025, 10:10:52 PM
Quote from: ASword on March 12, 2025, 09:39:45 PMThanks for the link.  Unfortunately it just leaves me confused again.  This seems to imply that houses are wired single phase (with 3-wire connections), and that matches my generator (which makes sense)... but that throws into question the "other" inverter's requirement that a generator must output 240v split phase. 
Look again - In US most houses are wired split phase  look at diagram lower on that page.
It shows that in single phase there is no voltage between the two  hot wires.
In split phase there is 240v between the two  hot wires.
Larry
Title: Re: Single phase 240v generator compatible?
Post by: ASword on March 12, 2025, 10:52:28 PM
This makes no sense though... the diagram shows no 240v differential, just two 120v legs?  But it's a 240v generator and we've got several 240v loads on it, so I know it's delivering 240v.

And on another site there are people with it wired up to inverters that require a 240v generator.
Title: Re: Single phase 240v generator compatible?
Post by: ClassicCrazy on March 12, 2025, 11:21:40 PM
Yeah , better look on some other source - maybe I picked out a bad one to share !
Larry
Title: Re: Single phase 240v generator compatible?
Post by: FNG on March 13, 2025, 06:16:57 AM
In the US a split phase home is Single Phase, At the street there is one hot leg and a neutral that go into the transformer on the pole (or ground) and that transformer is a lot like the Trace or Outback autoformers in that it creates a split of the single phase. The Phases are in line with each other as that one peak and one dip line up at 180 degrees out from each other

That all said yes the AIO requires 120/240 split phase it will require a neutral

L1 is 120V to Neutral
L2 is 120V to Neutral
L1 to L2 is 240V
Title: Re: Single phase 240v generator compatible?
Post by: ASword on March 13, 2025, 10:25:11 AM
Okay, so the generator says "single phase", but it must be split in order to generate the two legs that the house requires.  This seems mostly a terminology issue, no?  Would a split phase 240v generator be different than a single phase 240v generator?
Title: Re: Single phase 240v generator compatible?
Post by: FNG on March 13, 2025, 03:29:14 PM
The two terms mean the same thing in North America so yes its just different ways of saying the same thing
Title: Re: Single phase 240v generator compatible?
Post by: ASword on March 13, 2025, 05:11:36 PM
Thank you for clearing that up.
Title: Re: Single phase 240v generator compatible?
Post by: DarkForestSolar on March 13, 2025, 06:52:28 PM
Yup, in the US, single phase and split phase are used interchangeably to talk about the same thing -- our standard residential service with 120 volts line to nuetral and 240 volts line to line.  Doesn't make sense, but it's what we do here  ::)
Title: Re: Single phase 240v generator compatible?
Post by: ASword on March 14, 2025, 10:48:20 AM
What amazes me most is how long it took to get a clear answer to that question.