Looking for some input on a small Inverter - generator

[K.Aoi]

You should look at the manual before buying an inverter for the max draw under “eco” mode, which is when the inverter is actually working. When you exceed that they revert to a standard generator running at 3000rpm negating any fuel savings. My cheap WEN is at 60% of its 3500W constant rating.

I measured all the max surge on things I would run with a decent clamp meter and a cord with individual conductors. I was actually surprised by the surge on some things. I have a 6500BTU A/C that surged to almost 18A one time. I guess it’s for a very short time because it doesn’t flip the breaker.

This is incorrect. In any mode, they are capable of their full rated wattage. At maximum output, the engine is turning the same RPMs regardless of eco mode or not (it's actually 5000RPM or so for almost all of these smaller units at maximum load). The only difference is that it lowers the engine speed under no/low load, the inverter itself does not have its output limited. The inverter is always "working". There is no time when these function like a standard brushed or brushless generator with the output connected directly to the windings on the generator head.

You are correct however in that the surge under startup of a large motor could put some stress on it as unlike a regular generator you can't rely on the rotational momentum of the rotor to overcome startup surges, but the inverters contain a capacitor that can help bridge the slight gap to the engine speed increasing.

 

[spasm3]

Yes, definitely consumed faster and why an inverter would be a must
Good news is if it was an extended outage, I could always then switch over to gasoline, but I would like to avoid that if it is ever needed because I don’t want the hassle of draining gasoline for something that might get used once or twice a decade

How much do you want to spend?

Champion has a 2500 watt portable for just under $600 that is dual fuel. Its small. They claim 25 hour run time on a 20 gallon propane tank.

If you do go that route, blue rhino tanks are not full, if you get a new tank, take it to tractor supply and top it up.

I do hear that generators are not easy to start on propane.

https://www.amazon.com/Champion-Pow.../B0CRLWJSSX/ref=sr_1_5?crid=38CV3VQ9UJM2G&dib

 

[SC Maintenance]

This is incorrect. In any mode, they are capable of their full rated wattage. At maximum output, the engine is turning the same RPMs regardless of eco mode or not (it's actually 5000RPM or so for almost all of these smaller units at maximum load). The only difference is that it lowers the engine speed under no/low load, the inverter itself does not have its output limited. The inverter is always "working". There is no time when these function like a standard brushed or brushless generator with the output connected directly to the windings on the generator head.

You are correct however in that the surge under startup of a large motor could put some stress on it as unlike a regular generator you can't rely on the rotational momentum of the rotor to overcome startup surges, but the inverters contain a capacitor that can help bridge the slight gap to the engine speed increasing.

It was a typo - should be 3600rpm. A 2 pole generator at 3600 is 60Hz AC power - well alternator I guess right? So while it might still be running through the inverters coils there is little or no frequency to invert. Maybe cleans it up?

The Honda 212 and clones are typically governed at 3800 rpm and the servo controls to 3600 on full run or after about half load. Or at least that’s what the wiring diagram infers There not built for 5000 rpm constant I don’t think. Maybe others are?

If I am in “eco” and I add over half rated load it goes immediately to full rpm. I had assumed this is to not overheat the inverter?

 

[K.Aoi]

It was a typo - should be 3600rpm. A 2 pole generator at 3600 is 60Hz AC power - well alternator I guess right? So while it might still be running through the inverters coils there is little or no frequency to invert. Maybe cleans it up?

The Honda 212 and clones are typically governed at 3800 rpm and the servo controls to 3600 on full run or after about half load. Or at least that’s what the wiring diagram infers There not built for 5000 rpm constant I don’t think. Maybe others are?

If I am in “eco” and I add over half rated load it goes immediately to full rpm. I had assumed this is to not overheat the inverter?

These operate like a PC switch mode power supply. They don't invert directly to 60hz. They take the AC input, rectify it, then using FETs convert it to several hundred khz AC, then rectify and convert that back to 60hz, and output voltage is maintained with PWM. I suppose it's possible the bigger ones are governed to 3600-3800. The smaller 80cc and similar sizes like on the ones we've been talking about in this thread (2000w sized ones) will sit at 5000RPM. My old predator 1100/1400 and my current bilt hard 2000/2500 run at 5200rpm at full load.

 

[Cruisin'n5thgear]

I have two non-inverter generators, 18 hp and 5 hp, and I 100% agree on the value of an inverter unit. Noise and fuel consumption will be vastly improved. I'd recommend oversizing by 25% to be on the safe side. Keep in mind running loads will be two thirds to half of the startup voltage you're planning for, so the set won't be running at max amps the entire time.

 

[Rand]

I have two non-inverter generators, 18 hp and 5 hp, and I 100% agree on the value of an inverter unit. Noise and fuel consumption will be vastly improved. I'd recommend oversizing by 25% to be on the safe side. Keep in mind running loads will be two thirds to half of the startup voltage you're planning for, so the set won't be running at max amps the entire time.

I would say that's mostly correct, except if you're running a generator at 60% load or more. There won't be that much difference in noise or fuel consumption.
The nice thing about inverter is you can oversize your generator for your biggest loads yet still have fuel savings on smaller loads.

Ie 1000w load on a 3500w unit etc

 

[alarmguy]

How much do you want to spend?

Champion has a 2500 watt portable for just under $600 that is dual fuel. Its small. They claim 25 hour run time on a 20 gallon propane tank.

If you do go that route, blue rhino tanks are not full, if you get a new tank, take it to tractor supply and top it up.

I do hear that generators are not easy to start on propane.

https://www.amazon.com/Champion-Pow.../B0CRLWJSSX/ref=sr_1_5?crid=38CV3VQ9UJM2G&dib

IN my first post #1 I would be ok with $850 and better if I pick it up on sale. Seems like the price is in line with what you posted taking into account in post #1 it is rated at 3,200 watts which will be a little less on propane gas instead of gasoline.
https://www.costco.com/firman-3200w...uel-inverter-generator.product.100843922.html