LPG gas portable generators?

[solardreamer]

That truly is a nasty waveform. But in 50 years, I've never heard of a alternator such as you describe. A web search only brings up AC Delco automotive alternators, nothing like what i'd use at my house to get 9Kw out of. Looking at the schematic I posted, what kind of alternator do you call that ?

I don't really know but I was certainly not happy to see that waveform and I have had to learn more about engine generator/alternator/AVR then I care to. Before I finally decided to bite the bullet and get inverter generator for things that don't work with alternator/AVR generators I did do some research and it seems others have also seen similar. Here is some YouTube videos I had collected in my research that show similar waveform:

Starting at 5:40 in https://www.youtube.com/watch?v=CEVsRex43K8
Starting at 26:00 in https://www.youtube.com/watch?v=I2-3dyBHlhc

https://www.youtube.com/watch?v=Y1IK3w7lwqI

The generators are all different make and model so I concluded it's not uncommon for alternator/AVR generators and I couldn't find any practical way to clean up the power so I gave up. I should have suspected early on from the fact that generator vendors don't typically provide THD specs for their alternator/AVR generators. As ugly as the waveform is the THD still probably between 5-10% and works fine with many devices.

[Mike90250]

That truly is a nasty waveform. But in 50 years, I've never heard of a alternator such as you describe. A web search only brings up AC Delco automotive alternators, nothing like what i'd use at my house to get 9Kw out of. Looking at the schematic I posted, what kind of alternator do you call that ?

[solardreamer]

This is the time I call "put up or shut up" . There is no consumer generator I know of, that uses a 3 phase motor as a generation device. They nearly all use a conventional rotating field alternator (some are split phase for 240V & 120V output) to produce power. Unless highly loaded, they create a nearly perfect sine wave.
You can see the labels on the winding below, Main1 , Main2 , Field winding, Excitation/ AVR winding, the mains go straight to the outlets via a circuit breaker.
Inverter generators use a poly phase alternator, which is rectified to DC and then a inverter produces AC from that.

Example schematic:Firman_H07552-Electrical.pdf.png

Sorry I meant to say 3 wire alternator (for 120V/240V generator). Attached is the output wave form with noise.

[Mike90250]

It depends on what you mean by "home AC charger"? The generator you referenced seem to a
traditional portable generator (i.e. not inverter generator) that
typically uses a 3-phase AC motors to generate single phase ~60hz sinusoidal voltage waves that usually have 2400Hz noise
riding on top of the 60hz waves. So, the power is sinusoidal but not as clean as grid power. Many devices can work with such power but not all. I can tell you such power not clean enough for the charger in my electric car. You will need to use inverter generators for sensitive devices that require clean power.

This is the time I call "put up or shut up" . There is no consumer generator I know of, that uses a 3 phase motor as a generation device. They nearly all use a conventional rotating field alternator (some are split phase for 240V & 120V output) to produce power. Unless highly loaded, they create a nearly perfect sine wave.
You can see the labels on the winding below, Main1 , Main2 , Field winding, Excitation/ AVR winding, the mains go straight to the outlets via a circuit breaker.
Inverter generators use a poly phase alternator, which is rectified to DC and then a inverter produces AC from that.

Example schematic:Firman_H07552-Electrical.pdf.png

[solardreamer]

Can you say if the green power CC2500 LPG genny is clean enough for a typical home AC Charger?

It depends on what you mean by "home AC charger"? The generator you referenced seem to a traditional portable generator (i.e. not inverter generator) that typically uses a 3-phase AC motors to generate single phase ~60hz sinusoidal voltage waves that usually have 2400Hz noise riding on top of the 60hz waves. So, the power is sinusoidal but not as clean as grid power. Many devices can work with such power but not all. I can tell you such power not clean enough for the charger in my electric car. You will need to use inverter generators for sensitive devices that require clean power.

[Mike90250]

Why consider an LPG Conversion?


LPG converted engines will also run off of natural gas, making them great for areas with gas mains in a power outage.

You need a 2nd conversion to configure the orifice for Propane or Nat Gas. 2 different fuels, need different orifice. ( at least for stoves, water heaters and BBQ grills )

[Heatmypannel]

Why consider an LPG Conversion?

So, you have a perfectly good, gasoline-fueled, air-cooled portable genset. Why in the world would you want to hack it up (relatively speaking) to run off of Propane?

These are some of the reasons that have recently been cited for making such a conversion.
Unlike gasoline, LPG does not degrade over time. Therefore, you always have a fresh, clean, water-free fuel source – even after months or years of storage.
LPG will not evaporate from the carburetor fuel bowl and leave gummy residues to clog fuel jets like liquid gasoline.
LPG burns cleaner – supposedly better for the environment.
We do not pay high road or motor fuel taxes on LPG. Therefore, the cost per gallon is often lower than gasoline.
If dedicating the genset to a 5th wheel or travel trailer, you do not need a new fuel source. The genset gas tank can be removed and the RV LPG supply used.
When traveling, extra containers of gasoline are not needed. No slosh, spillage or evaporation. Also, lower risk of fire compared to an atmospherically vented gas tank/container.
The LPG fuel source can easily be 30 or more feet from the genset allowing diverse installation opportunities.
For home back-up power use, large LPG tanks are available for long term power outages (my home tank is 300 gallons and buried in the back yard – my last fill-up was $2.16 per gallon).
LPG converted engines will also run off of natural gas, making them great for areas with gas mains in a power outage.
Five-gallon LPG exchange tanks are available at most home stores, convenience markets, Wal-Mart and gasoline stations. Most larger campgrounds offer to fill with larger LPG tanks.
Converted gensets are easily externally readjusted to compensate for altitude variations.
Contrary to some info, converted gensets DO NOT produce any less power than they did when burning gasoline.
Many of the small air-cooled engines can be easily and inexpensively converted to tri-fuel. These conversions will run off of gasoline, LPG or NG. My GX390 home backup genset is converted in this manner as was my previous B&S genset.
A 5-gallon OPD style LPG tank will hold 4 gallons of liquid propane (now that’s a real oxymoron!). Enough fuel to run a typical GX200 class engine for over 24 continuous hours.

<link removed> Mod note: Please don't use this forum to promote your site.

[Bala]

Thanks. So by the sounds they all must have the ability to disable the governor for constant rpm? Or else how can an appliance run properley while other loads vary. There are no small portable inverter lpg units in my area and lpg is more appealing to me than petrol. All inverters are petrol.

They dont disable the governor, the governor is always working.

The Governor regulates the throttle to keep engine running at the required RPM.

Just like cruise control in a car varies engine power to keep the car at the preset speed.

[Mike90250]

Thanks. So by the sounds they all must have the ability to disable the governor for constant rpm? Or else how can an appliance run properley while other loads vary. There are no small portable inverter lpg units in my area and lpg is more appealing to me than petrol. All inverters are petrol.

You seem to not know how an inverter generator works. They generate a high voltage, of varied frequency, which powers an INVERTER. The inverter provides a clean, stable sine wave. The engine is controlled to only burn enough fuel to satisfy the demand of the inverter, it's RPM varys quite a bit.

There are conversion kits, that allow you to convert a gasoline carburetor to LPG.
Because LPG, propane, natural gas all contain less energy than gasoline, the motor will only be able to produce about 80% of it's normal power, so you must de-rate the electrical capacity about 20% from gasoline

https://www.propanecarbs.com/honda-eu2000-tri-fuel-conversion.html

[Jman]

Inverter generators will maintain Hz and V at any engine RPM. In Eco Mode Engine RPM will vary depending on load demand.

A generator with a petrol 4 stroke engine, such as Honda GX Series and smaller diesels need to run at 3000RPM for 50Hz and 3600 for 60Hz, It does not matter if what the load is, The engine RPM controls the Hz and in some cases the V as well.

Many larger diesels will run at 1500rpm for 50Hz and 1800 rpm for 60Hz.

There are other configurations but they are the common ones.

Thanks. So by the sounds they all must have the ability to disable the governor for constant rpm? Or else how can an appliance run properley while other loads vary. There are no small portable inverter lpg units in my area and lpg is more appealing to me than petrol. All inverters are petrol.

[Bala]

That to me sounds like when the governor is lowering engine speeds to save fuel with lite loads that the frequency will be off? So no good if the appliance needs constant.

Inverter generators will maintain Hz and V at any engine RPM. In Eco Mode Engine RPM will vary depending on load demand.

A generator with a petrol 4 stroke engine, such as Honda GX Series and smaller diesels need to run at 3000RPM for 50Hz and 3600 for 60Hz, It does not matter if what the load is, The engine RPM controls the Hz and in some cases the V as well.

Many larger diesels will run at 1500rpm for 50Hz and 1800 rpm for 60Hz.

There are other configurations but they are the common ones.

[Jman]

Frequency = RPM. Generators depending on engine type run at 1800, 2400, 3000, up to 3600 RPM's and the governor controls the engine RPM.

That to me sounds like when the governor is lowering engine speeds to save fuel with lite loads that the frequency will be off? So no good if the appliance needs constant.

[Mike90250]

Can you say if the green power CC2500 LPG genny is clean enough for a typical home AC Charger?

I have no idea. But, probably, yes, if the voltage & Fq is correct.

[Sunking]

I think the LPG idea is dead - lack of portable inverter ready to go units where I'm located, the conventional AC units as far as I can tell don't produce smooth pure sine wave power. Confused as they run an alternator (AC) which I would have thought would be similar to the way utility companies do.

You are confused because Alternators do not generate usable AC power, they generate DC power. The genny has a built in Modified Sine Wave or True Sine Wave Inverter. Alternators are generators at the root level. In fact most are 3-phase Generators. What makes them Alternators is the built-in rectifiers and voltage regulators that change AC to DC.

On conventional does the frequency (50-60hz) change when the revs lower with governor?

Frequency = RPM. Generators depending on engine type run at 1800, 2400, 3000, up to 3600 RPM's and the governor controls the engine RPM.

[Jman]

Most portable IC engine generators produce a pretty decent sine wave. The frequency is governed by the RPM, so the better the RM regulation, the better time your clock will keep. However, frequency can vary + or - 5 hz [55-65 hz ] and won't cause much problem.

Can you say if the green power CC2500 LPG genny is clean enough for a typical home AC Charger?