Onan Carbs

[DonTom]

And, with CARB's recent generator ban

I wonder how it is possible to make a zero emissions genny as it says here.

"Portable generators, including those in recreational vehicles, would be required to meet more stringent standards in 2024 and meet zero-emission standards starting in 2028."

Speaking of gennys, what is the advantage with a 3600 RPM 4KW genny over a 4KW inverter genny?

And are any of the inverter gennys fuel injected?

-Don- Reno, NV

 

[DonTom]

Carson Valley RV Resort and Casino.

In Minden, NV, which is south of Carson City?

-Don- Reno, NV

 

[Mark_K5LXP]

are any of the inverter gennys fuel injected?

Google sez lots and lots. Ex: Honda EU3200i

The EU32000i features the powerful Honda GX130 Fuel-Injected Engine that automatically adjusts for elevation, so no jets are required

Mark B.
Albuquerque, NM

 

[DonTom]

The EU32000i features the powerful Honda GX130 Fuel-Injected Engine that automatically adjusts for elevation, so no jets are required

So why can't they use those in RVs instead of the Onans? The Inverter Gennys are usually cheaper and better designed. Is there any advantage to the 3600 RPM Onans over the cheaper and better designed inverter gennys? I cannot think of any.

-Don- Reno, NV

 

[Isaac-1]

A zero emission generator by their definition is also known as a battery, either that or it runs on Hydrogen

 

[DonTom]

A zero emission generator by their definition is also known as a battery, either that or it runs on Hydrogen

I was wondering if that was it. TBH, I like the idea to have a big fat many KWH battery in an RV instead of a genny as long as there are convenient ways to keep it charged up.

-Don- Reno, NV

 

[Lou Schneider]

I wonder how it is possible to make a zero emissions genny as it says here.

"Portable generators, including those in recreational vehicles, would be required to meet more stringent standards in 2024 and meet zero-emission standards starting in 2028."

Speaking of gennys, what is the advantage with a 3600 RPM 4KW genny over a 4KW inverter genny?

And are any of the inverter gennys fuel injected?

-Don- Reno, NV

A zero emissions generator is a battery coupled to a solar panel. Or an exercise bike coupled to an alternator. Don't f*rt.

An inverter generator doesn't lock the engine RPM to the generator's output frequency. This means the engine can slow down from it's rated speed under a light load and still provide a 60 Hz output.

 

[Mark_K5LXP]

So why can't they use those in RVs instead of the Onans?

First thought is cost. But it's not like the 4K's are cheap. But at contract pricing maybe cummins comes in lowest bidder. Next is specs. The cummins have what amounts to be a commercial operating spec. Temperature, humidity, altitude, output stabililty, on and on. Maybe conveyable warranty is part of it. Retrofitability/backwards compatibility. Mechanical mounting, or Interfacing for power connection and remote control. That's not to say maybe there are inverter gensets that are up to it, after all cummins makes RV inverter gensets. But it's probably unrealistic to believe a basic box store pull start inverter genset is up to everything a commercial grade model that's qualified for the purpose. It could be a don't care for you if it doesn't start at 0F or shuts down at 105F under load, or any of the possible corner cases you'd encounter in daily operation but it's seemingly important enough for RV builders that there's no pervasive alternative yet.

A ham radio example is bofang vs motorola radios. On paper the bofangs do most of what a motorola can. When I'm at a gathering and people comment about my clunky motorola I'll toss it over my head and let it hit the ground, then invite them to do the same with their bofang. There's good and good enough to be be sure when it comes to most things, but especially when it comes to equipment there are specs and reasons for specs so it is useful to understand what drives particular choices.

Mark B.
Albuquerque, NM

 

[DonTom]

First thought is cost.

The Onans are not cheap and can get a better designed inverter genny for less. A 4KW Onan RV genny costs around $4,300.00.

But this inverter genny cost less than 1K$.

So why do the Onans cost four times the price of a new inverter genny? What is the big advantage of a non-inverter genny?

-Don- Reno, NV

 

[DonTom]

An inverter generator doesn't lock the engine RPM to the generator's output frequency. This means the engine can slow down from it's rated speed under a light load and still provide a 60 Hz output.

Yes, I understand how they work, I think, with a middle DC stage so the RPMs (frequency) into it makes no difference. The inverter runs from the DC in the inverter genny's middle stage and is a 60 hz and pure sinewave. So this means it can run slow and extra quiet on a small load and runs faster with more noise on a heavy load. Do I have all of this correct?

Anyway, I see the advantages of the inverter genny, but I do not see the disadvantage, which is what I am asking about. What is it that justifies four times to price with an anciently designed Onan that does LESS than an inverter genny?

-Don- Reno, NV

 

[Larry N.]

One question Don -- can you run the Honda or the Yamaha large inverter unit for 4 or five days without stopping, time after time after time, perhaps for 4K or more hours with nothing more than oil and filter?

Obviously I'm thinking longevity...

 

[DonTom]

One question Don -- can you run the Honda or the Yamaha large inverter unit for 4 or five days without stopping, time after time after time, perhaps for 4K or more hours with nothing more than oil and filter?

Obviously I'm thinking longevity...

I don't think anybody runs an RV genny for four days non-stop. But both types have a short duty cycle rating at full capacity but should run forever at a reduced capacity. At least that is what I expect.

But I do not really know, but that is the type of stuff I am trying to find out--where the disadvantage is of the inverter genny--if there is one.

-Don- Reno, NV

 

[Isaac-1]

On advantage of the Onan KY 4000 over most inverter generators is build quality, use of all copper windings, Forest Service certified spark arrestor, certified to meet National Park sound level requirements, etc. This is not saying which is quieter, but that Onan has went through the certification process and is listed with the government as being in compliance. Though the same can be said for Honda inverter generators, but of course those are not cheap either, the Honda EU 3200i ( 3200 watt inverter generator) retails for $2,800. Note my 2002 Onan KY 4000 has just over 1,500 hours (I exercised it today and noticed it had crossed the 1,500 hour mark on the hour meter), how will those cheaper inverter generators be doing at 1,500+ hours of run time.

 

[Mark_K5LXP]

where the disadvantage is of the inverter genny--if there is one.

Today it seems lack of a commercial grade one that has features I outlined above - mounting options, remote control, environmental (temp, vibe, humidity), sound/vibration isolation, possibly operational life. When you look at the Cummins 4K spec you see performance ratings, and not just numbers on a sheet but are qualified by ANSI, RVIA, UL/CSA and other bodies that have specific test and approval standards for mechanical and electrical operation. One can dismiss these as superfluous or not applicable but any gensets that can meet them would be in the running for this application too. It's not zero, there's a few RV inverter gensets but they're right up there in price with the cummins. Let the better genset win. The 4K and 5.5K are the ones to beat - not unbeatable for sure but there is a market penetration and legacy that can't be dismissed.

Mark B.
Albuquerque, NM

 

[DonTom]

Though the same can be said for Honda inverter generators, but of course those are not cheap either, the Honda EU 3200i ( 3200 watt inverter generator) retails for $2,800.

That still is cheaper than an 4K Onan. IIRC, the 4K Onan can only do 3,500 VA continuously. I don't know how the Honda is rated for continuous.

I somehow expect a 3KW inverter genny will do a better job at 7K' elevation than will my 4 KW Onan.

-Don- Reno, NV

 

[DonTom]

remote control,

The Westinghouse 5000 Peak Watt inverter genny in my message 49 here comes with a wireless remote and several other nice features.

I find doing something like this to be tempting:

-Don- Reno, NV

 

[Isaac-1]

If you really want to replace your KY 4000 with an inverter generator the logical choice is the new Onan HGLBA QG 4000i https://www.absolutegenerators.com/...w-prime-single-phase-120-volt-air-cooled-evap It is a bit pricey, but is a near drop in replacement for the KY 4000

 

[Mark_K5LXP]

I'm sure you're not the first to ponder this, but as someone that is involved in the design and production of industrial and military hardware all I can think is you aren't aware, or out of hand dismissing the significance of specifications and performance standards. You may decide, or maybe know that you don't care about that extended performance and in that case, you likely could substitute a $1K retail genset for a $4K commercial one. It could probably be argued that one could replace the retail genset four times and still break even. But to be sure, they're not equivalent.

I somehow expect a 3KW inverter genny will do a better job at 7K' elevation than will my 4 KW Onan.

Why? A different normally aspirated engine isn't subject to altitude? Or, the obvious conclusion a properly functioning one will be better than a compromised one? It's not that the 4K is inherently poor, it's your 4K that's poor.

Mark B.
Albuquerque, NM

 

[DonTom]

A different normally aspirated engine isn't subject to altitude?

Not in the same ways, nothing near it.

Compare a muscle car from the early 1970's to a modern gutless 4-cyclinder small engine car on a hill above 7,000' elevation and you will get your answer. Yes, they both loose power, of course, but perhaps about 80% of the power is lost in the 1970's car and perhaps 15% in the modern car, which can still speed up such a hill, unlike the old muscle car which can beat almost anything but only near sea level.

I have been up at Donner Summit (7,240' elevation) countless times back in the early 1970's until 2024 in countless different vehicles. It is very common for the car (or motorcycle) with the most power at sea level to have the least power at 7,240' feet when comparing vehicles, such as when comparing a car with a map sensor to one without, even if both are carb engines. Back in the late 1960's most cars could only go at around 40 MPH max with the pedal to the metal when going uphill near 7,000' elevation. Today's little gutless cars can get speeding tickets up there these days. They do not even notice the difference up there. It's just like the same hill at sea level. But yeah, there is less power but we cannot even feel the difference in a modern car when compared to sea level.

But to be sure, they're not equivalent.

I do not claim they are equivalent. But I am asking about normal use in an RV, not an industrial use.

it's your 4K that's poor.

Could be, but it is also the design that is poor. Where is the air pressure sensor in an Onan? Where is the EFI? Where are the sensors to make sure the genny mixture is always 14.7-1 after warm up? Where is the chip to keep it at 3,600 RPMs? Where are the hydraulic valves that never need adjustment? Or even bucket and shims? The 1950's design doesn't even have a CV carb. Not even in my 2022 Onan. But my 1971 BMW motorcycle did when new in 1971.

But it could be that my 4K genny is extra poor. And probably is.

I wonder how well a new 4K Onan would do close to 3KW load at 7K' in reality despite Onan's claims.

BTW, if I only use my Onan to charge the house battery and some other small loads, it is fine at 7K' other than I have to increase the RPM adjustment and lower it again when I get back to lower elevations to keep it near 3,600 RPMs. That alone probably shows there is something wrong with my genny.

-Don- Reno, NV

 

[DonTom]

If you really want to replace your KY 4000 with an inverter generator the logical choice is the new Onan HGLBA QG 4000i https://www.absolutegenerators.com/...w-prime-single-phase-120-volt-air-cooled-evap It is a bit pricey, but is a near drop in replacement for the KY 4000

I will only replace the genny as a last resort. I expect to be able to improve the one I own.

I see the specs on the Onan HGLBA QG 4000i says in the owner's manual it runs from 2,400-to 2,900 RPMs, but I find it strange that it does not mention being an inverter genny any where I could find. But I guess the RPM range is a good indication that it must be an inverter genny--or is it some other weird design?

But the specs on the bottom of the page show it is NOT an inverter genny :

Engine RPM	3600 RPM
Generator RPM	3600 RPM

Can you explain that?

-Don- Reno, NV