clean power generator questions

[Darren]

The old Clary is an example of a "online" UPS:
Uninterruptible power supply - Wikipedia, the free encyclopedia

Contrast with an "offline" UPS, such as the type you find at Walmart:
Uninterruptible power supply - Wikipedia, the free encyclopedia

Wrooster

In a nutshell, the Clary UPS doesn't care about the quality of the power put out by the generator because it's only going to use it to charge batteries. The sensitive electronics never see the generator output. The small Zenith UPS, a rebranded Clary, I used years ago would run a computer for hours after the power died. The little Zenith UPS weighed close to thirty pounds and was the size of a regular rural mailbox.

 

[Mark @ Everlast]

Again, I am not an electronics expert as I have said several times, but I know people who are...:laughing:

But Lincoln and Miller will tell you NOT to use their older welder generators for powering their newer inverters because they are NOT clean...And they are about as good of generator as they come.

 

[Redneck in training]

If you want to know how good is your power be it from utility or your geny use digital oscilloscope. All of them even the cheapest one have Frequency analyzer. Pure sine wave will not produce harmonic frequencies. If there are harmonic frequencies (multiples of the base frequency) the sine wave is not pure. needless to say that the load has also effect on the power quality at place of measurement.
Some inverters produce very good sine wave. They rectify input current and then chop it into "pulses" of various duration to create a stepped sine wave. The sine wave is then smoothed in an output filter. Since they have a feedback comparing what is coming out with what you want to come out it corrects instantly for all imperfections.

Since inverters first rectify the input current my thinking was that they care less about power quality.

 

[ultrarunner]

Where do the Honda 1000, 2000 and 3000 inverter generators rate?

 

[Redneck in training]

Check Yamaha inverter generators. They claim to have pure sine wave inverters.

Here is some good read about the some generator issues.

Joker Bug 400 and camping battery

 

[Soundguy]

How did you determine frequency stability was better on the generator?

Wrooster

uh.. probably this portion of my quote: "you might be surprised at looking at your grid power and a good genny output on a graphing oscope or meter"

as another poster mentioned.. freq counting and anylysis is built in to even the cheapest graphing meter... and yes to answer your next question.. I have one... Just look at the graph over 'T'... that will show you freq stability.

soundguy

 

[wrooster]

uh.. probably this portion of my quote: "you might be surprised at looking at your grid power and a good genny output on a graphing oscope or meter"

as another poster mentioned.. freq counting and anylysis is built in to even the cheapest graphing meter... and yes to answer your next question.. I have one... Just look at the graph over 'T'... that will show you freq stability

Since I asked "how" not "what you used", I'll try to determine how you gathered the data by reading between the lines above...

You...
1) plugged the probes of the "graphing oscope or meter" into the generator output, and took an instantaneous frequency reading along with some periodic data points which you graphed versus time, then
2) repeated the above using the utility power as input to the "graphing oscope or meter".

Is this correct?

Subsequently you...
1) computed the mean value and/or deviation from the meter's idea of 60Hz for both the generator and the utility power over a given time interval, then
2) compared the two and determined that the generator was either more accurate to 60Hz, more stable around 60Hz, or both.

Is this correct?

What were the utility and generator deviations, and over what period of time?

Wrooster

 

[955Lincoln]

But Lincoln and Miller will tell you NOT to use their older welder generators for powering their newer inverters because they are NOT clean...And they are about as good of generator as they come.

They are good mechanical and durability wise but not well regulated and clean. When welder companies first started adding AC generators to their machines it was just a convenience and marketing item to run power tools and such. Electrical wise I would rate them comparable to the big box store generators. It's tough running welders or other large current devices on a motor generator because when it is suddenly unloaded they need to keep the voltage from spiking.

 

[955Lincoln]

Where do the Honda 1000, 2000 and 3000 inverter generators rate?

Top shelf....I wouldn't hesitate to run anything with these generators as long as they are loaded correctly. They use true sinewave inverters.

 

[Redneck in training]

Since I asked "how" not "what you used", I'll try to determine how you gathered the data by reading between the lines above...

You...
1) plugged the probes of the "graphing oscope or meter" into the generator output, and took an instantaneous frequency reading along with some periodic data points which you graphed versus time, then
2) repeated the above using the utility power as input to the "graphing oscope or meter".

Is this correct?

Subsequently you...
1) computed the mean value and/or deviation from the meter's idea of 60Hz for both the generator and the utility power over a given time interval, then
2) compared the two and determined that the generator was either more accurate to 60Hz, more stable around 60Hz, or both.

Is this correct?

What were the utility and generator deviations, and over what period of time?

Wrooster

Connect digital scope to the grid or generator and start Spectrum analyzer built in the scope.

Attached files show scope examples of sine and square wave with their respective spectrum. Sine wave has only single frequency present. Square wave has many frequencies present with large peak at every odd multiple of the base frequency. Those signals were generated by a signal generator. Power generated by the utility or generator will be somewhere in between of those. In addition the power can contain voltage spikes (in example lightning strikes) and dips (in example caused by overload). But that is another issue altogether.