Inverter generators and Onan

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.

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.

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.

Yeah

Right

But 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.

Like most 'stories' the situation has evolved, but the story has not
20 years ago maybe more, if you bought an open frame portable generator
Chances are it didn't have electronic automatic voltage regulation aka avr
Instead it had permanent magnet field and maybe a Diode capacitor clipper
It relied on feild saturation and the door cap circuit caused ugly spikes in the wave form, which screwed with electronics
This was not an Onan, and not the newer versions of good quality open frame portable generator

And there will always be those few, that think only the newest technology is best for everything

I have an inverter generator, very happy with it
But except for the fact that it is less loud
It does not out perform the Onan or it's open frame predecessor
And they both out perform the inverter when it comes to load surge's

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.