There are a lot of threads on here about inverter genny's, and the main positives are quieter and clean power, OK, inverter for clean power, When buying just an inverter the standard everyone goes for is pure sine wave, Got it, so,,,,,Onan genny's have been around forever, they dont call themselves inverter generators, they seem to be electronically controlled but not really any different than the open frame portable generators. I know folks have commented about standard genny's harming some electronics and the same for modified sine wave inverters.So for the electrically minded folks, why isnt a pure sine wave or inverter important on a permanently installed Genny? No snark intended, I am honestly curious why , what appears to be a double standard.

The better waveform, overall lower fuel consumption, and quieter operation are important on built-in generators. The Onan product line has gone to inverter technology in many of the higher end models. In the lower power range, the RV makers keep installing the old technology and we keep buying them. No competition, cash cow, etc., come to mind. The waveform looks downright nasty with some loads, yet "everything" seems to work just fine with it.I have a noisy-as-heck built-in microquiet and carry a portable inverter generator. For fast things like running the toaster or microwave, it's hard to beat the convenience of the built-in. For longer term things like battery charging, I use the portable.

Like most 'stories' the situation has evolved, but the story has not20 years ago maybe more, if you bought an open frame portable generatorChances are it didn't have electronic automatic voltage regulation aka avrInstead it had permanent magnet field and maybe a Diode capacitor clipperIt relied on feild saturation and the door cap circuit caused ugly spikes in the wave form, which screwed with electronicsThis was not an Onan, and not the newer versions of good quality open frame portable generatorAnd there will always be those few, that think only the newest technology is best for everythingI have an inverter generator, very happy with itBut except for the fact that it is less loudIt does not out perform the Onan or it's open frame predecessorAnd they both out perform the inverter when it comes to load surge's

I am waiting for the day when the Mastodon decides the ice-age has moved on. Onan. Sooner or later the company may decide the time is right to introduce an inverter RV generator. If they are intelligent an ECU fuel injection system would accompany the upgrade along with overhead cam engine design.YeahRightBut you are correct about generators and waveform and voltage regulation.When a generator supply house telephoned me in 1982 asking if I was interested in a number 4 mounting 12.5 Kw single phase generator my eyebrows rose. It turned out to be an orphan. Coupling a 12.5 Kw generator to a #4 mount prime mover is not common.So, I drove a thousand miles to go look at it. It was crated in pine boards. Had insanely heavy plastic sheeting sealed up tight. I showed the man my hundred dollar bills and slit open the plastic. I sure as heck did not trust the old Mil-Spec documentation that was old and tattered. Mil-Spec automatically infers the machine may have been 400 Hz. Useless for my purposes.A strong vapor hit my nose and eyes. Vapor anti-corrosion liquid. The generator color was olive drab. What The Heck? Cosmoline on the spec plate. I rubbed it off. Manufacturer KATO. Model No. ML-125A-Spec(c) 120/240/480 vac. 50/60 Hz 12-6 lead reconnectable. 12.5Kw. 1000/1200 RPM. Inside the crate was a heavy pouch. Thick documentation and maintenance. USA mil manual.The company wanted way too much money for it. An hour of bitter bargaining ensued. I walked away owning the generator for $1,100. Expensive.What I ended up with is a Vietnam War era, Mil-Spec 12,500 watt generator orphan. Single phase. It weighs a whopping 120 pounds heavier than the only other (#8 frame) generator Kato produced at the time.The genspec called for a regulator that was not furnished with the generator. The governor was a Woodward mechanical. In 1986 I spent almost a thousand dollars for a Woodward electronic governor, plus a Delco H9000 voltage regulator. This may be one of the more expensive 12.5Kw generators ever assembled.But it was worth it. Cleaner more accurate power than public utility. But there is a glaring vulnerability I have done handstands trying to avoid.The dreaded BURP. Engine speed malfunction due to engine defect or fuel. I suspect an inverter type generator would affect the loads a lot less than a standard generator.

We have both an Onan and a Champion 3100 with remote start as we have become too accustomed to one button simplicity when starting our onboard. Although I have worked in the electronics industry for many moons and have a couple of o-scopes at home, I have never scoped either genny and see no real reason to do so as they have performed their jobs without issue. I do monitor AC voltages and frequency while they are in use, no biggie since the measuring device simply plugs into an outlet. They both can readily run my rig's AC unit which is mandatory for any generators I plan to use while RVing. I have powered everything contained in our rig with both units and items powered function exactly the same with either generator.Our Onan has been flawless for over 1K hours and a decade of heavy use, it is major overkill in most cases. Here steps in our Champion inverter genny, quieter, more fuel efficient, and surprisingly hardy. It easily gets the most use now since it can run our AC unit, the Onan still gets fired up when we need to power heavy current demand items for prolonged periods.

Onan must make good money from their gensets, since they are relatively less advanced than the portable generators going for 1/4 the price, although they are engineered for a niche market so they really can't do an economy of scale.However, it would be nice for them to go EFI and inverter based, partially so they are more resistant to fouling up, part for better fuel economy, and part for noise. We are in 2017, and 1970s generator tech needs to be updated for something that is more recent.I wouldn't mind seeing the generator have a built in battery or supercap system, so when a heavy inrush current from an A/C or microwave hits it, the inverter is able to handle the load from that, so the actual engine doesn't have to work as hard.

Inverter generators and Onan | Good Sam Community

MrWizard
Moderator
Jul 27, 2017
4 pole, 1800 RPM

they burnt that one bad, must have shorted out the load

NO sign, of the rotor doing any scraping
MEXICOWANDERER
Explorer
Jul 27, 2017
Well...
This generator TRIED TO BE a modified sine wave unit and it did - it did! Square, trapezoidal, sawtooth, but longevity reared its ugly head...
MrWizard
Moderator
Jul 27, 2017
well i did a parts search and a specs search for the ex350
and neither turned up any comments about inverter or electronics
just the usual mechanical, ignition, and alternator head

So i will apologize for getting it wrong, with caveat that i did search for info
road-runner
Explorer III
Jul 27, 2017
MrWizard wrote:
NOT unless it used an MSW inverter
and i don't think it does/did

what it probably has is a saturated laminated core
the is fine for lighting etc.
but gives an ugly wave form when attached to an inductive load
It's really annoying to research something before making a post only to have it challenged with a no-research opinion.

https://fortierjf.wikispaces.com/file/view/inverter_generator.pdf

http://www.petepower.co.uk/choosing-generators.html
(jump to section "Inverter generators")

http://www.pageoneja.com/manual-for-honda-ex350-generator.pdf
(search for "modified")

I didn't research this today, so I had to go back and find the info again to challenge the challenge.
joebedford
Nomad II
Jul 27, 2017
Personally I think inverter generators are WAAAYY louder than my Onan - all that UP down UP down as the load varies is very disturbing (to me).

My little MSW inverter handles all my computers, routers, TVs, etc without any generator.
MrWizard
Moderator
Jul 27, 2017
NOT unless it used an MSW inverter
and i don't think it does/did

what it probably has is a saturated laminated core
the is fine for lighting etc.
but gives an ugly wave form when attached to an inductive load
road-runner
Explorer III
Jul 27, 2017
Honda EX350 is MSW.
KD4UPL
Explorer
Jul 27, 2017
There's no such thing as a modified sine wave generator. They are all sine wave units. The sine wave is created by the rotation of the generator. That's the whole reason we use electricity produced in a sine wave, rotating generators.
As for the Onan, they seem to be largely solid dependable units with pretty good frequency and voltage regulation. That's where the cheaper generators are lacking, their frequency and voltage can be all over the place.
MEXICOWANDERER
Explorer
Jul 26, 2017
Sandia
Oscilloscope
New Mexico

=

Sandia National Laboratory?
kerrlakeRoo
Explorer
Jul 26, 2017
Sounds like this part of the industry has been allowed to stagnate. I dont currently use any apple products, but had heard folks complain of modified wave inverters destroying them so it just made the question on these generators seem natural. As someone who has worked with welders and similar equipment a long time, I'm surprised nobody has taken maybe a kawasaki engine like whats used in quite a few mobile welders now and built a nice inverter genny that way.
Those that have looked at these thx for the replies.

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