Another Generator question..

[TVG]

Anybody wanna weigh in on that gen I am looking at? Anyone have one? It is the champion inverter 3100 gen with remote start. 75537i.

[vsheetz]

Originally Posted by TVG

Anybody wanna weigh in on that gen I am looking at? Anyone have one? It is the champion inverter 3100 gen with remote start. 75537i.

This is the electric start version of what I have and commented in post #4 in this thread. Works well for me. Pro and con of electric start - more money, weighs more, vs. Convenience of electric start. That said, my generator is very easy to start - usually one light pull and its running.

[TVG]

Thanks Vsheetz! now how often do you really use it?

[1bigmess]

I love my trailer so far. It had one little plumbing issue that was fixed for free once I realized what the problem was and how to fix it. It tows great, is comfortable, and I'd do it all over again if I had to.

I bought it at Apache Camping Center in Portland, OR. Also a good experience.

[Mr_D]

Originally Posted by nothermark

Dirty power is not a smooth sine wave. *No* inverter generator is clean. All "pure sine" means is more than 3 steps in the wave form from the inverter.

So, the inverter manufacturers are lying to us when they advertise pure sine wave and show a wave form in their advertising?

[twinboat]

Originally Posted by Mr_D

So, the inverter manufacturers are lying to us when they advertise pure sine wave and show a wave form in their advertising?

Yes they are, Google it.

A power inverter device which produces a multiple step sinusoidal AC waveform is referred to as a*sine wave inverter. To more clearly distinguish the inverters with outputs of much less distortion than the "modified sine wave" (three step) inverter designs, the manufacturers often use the phrase*pure sine wave inverter. Almost all consumer grade inverters that are sold as a "pure sine wave inverter" do not produce a smooth sine wave output at all, *just a less choppy output than the square wave (one step) and modified sine wave (three step) inverters. In this sense, the phrases "Pure sine wave" or "sine wave inverter" are misleading to the consumer.

[skiles]

Originally Posted by TVG

Anybody wanna weigh in on that gen I am looking at? Anyone have one? It is the champion inverter 3100 gen with remote start. 75537i.

I have that generator except it's the Costco version, all black. I think I read where yours has electric start? Mine does not. I read many reviews and talked to some folks before I purchased it. I have been nothing but pleased so far. Easily starts first pull. I bought it last fall and haven't tried it with the AC yet, FWIW. I have used with the microwave, no problems. I don't have a lot of experience with generators, but from what a few friends have told me it's fairly quiet. It does not have an hour meter, so I just keep a mental log for each trip. I like that it has a 30 amp plug built in. So far so good.

My only minor complaint is performing an oil change can be a bit cumbersome. The drain is on the bottom of the unit and I have to position it just right on my workbench with part of it leaning off the side to get the funnel set up correctly. I hope this helps.

[nothermark]

Originally Posted by Mr_D

So, the inverter manufacturers are lying to us when they advertise pure sine wave and show a wave form in their advertising?

Yes. It's hype. A pure sine conversion would be an oscillator driving a class A amplifier with an efficiency under 50%. Instead they use multiple step voltages to approximate the sine wave output that is the normal output of a rotary generator. Doing that takes more complex circuitry and control than the "modified sine" free running square wave oscillators used to switch the cheaper inverters. Pure sine is like digital audio, close but not really the same. Probably better frequency stability on the "pure sine" but I would not guarantee accuracy.

While we are at the frequency. It is only an issue for clocks that track the line frequency. Other than that a few per cent error is not a big deal. Big changes may cause problems with the amount of iron in the core of transformers and motors but we are talking 10-20% as "big".

FWIW - back in the 1960's I did a class tour of the Robert Moses power plant in Niagara Falls, NY. I don't think they let most folks into some of the areas we were in. I remember the commutator being something like 10 - 20 ft in diameter coming up out of the floor of a room we were in with a digital counter that they used to check the frequency of the power grid. They would tweak the speed to keep the count correct to keep average clock time correct per a check with WWV. I imagine that has changed a bit given all the grid tie in done now. Maybe not. ;-)

[pasdad1]

Originally Posted by nothermark

Yes. It's hype. A pure sine conversion would be an oscillator driving a class A amplifier with an efficiency under 50%. Instead they use multiple step voltages to approximate the sine wave output that is the normal output of a rotary generator. Doing that takes more complex circuitry and control than the "modified sine" free running square wave oscillators used to switch the cheaper inverters. Pure sine is like digital audio, close but not really the same. Probably better frequency stability on the "pure sine" but I would not guarantee accuracy.

I'm not so sure it's hype. Take a look at this link. A guy puts various inverters from computer UPS, and a Honda EU2000i inverter generator on a scope. Looks like an almost perfect sine wave to me.

http://www.jkovach.net/projects/powerquality/

[1bigmess]

A couple of interesting papers on inverter generators by the Amateur Radio Relay League. Most interesting to me when I first saw these was the time to full output from no load testing.

http://www.arrl.org/files/file/QST%2...einschmidt.pdf
http://www.arrl.org/files/file/QST%2...612ProdRev.pdf

[RVGuy1966]

I went to deep fry for electronics and telecom so one of my pronects when I finally get to it is to build a pure sign rectifier to use when I have to run my genny. although I only start them wvery few months to keep them from rusting. I have been moving to solar for the past couple of months.

[nothermark]

Put the same low pass filter on the regular generator and the output will look like the Honda in the first QST article. That is part of what you pay all the extra money for. I don't see the relevance of the second one to noise. As far as that goes it would be interesting to find out the source of the noise in the first one.

Explain how they can do a high efficiency converter without chopping the wave form into samples and I will agree that there are no steps. As it stands I still say there are steps and then it is run through a low pass filter to smooth them out. Put $100 into a filter with the $100 generator and you will get the same result for $200 instead of $1000.

[pasdad1]

Originally Posted by nothermark

?.. Put $100 into a filter with the $100 generator and you will get the same result for $200 instead of $1000.

Except the $1000 generator is STILL more reliable AND MUCH quieter ! Plus the filter will NOT keep the frequency stable as this still depends on the RPM of a small 2cycle engine made in China by the lowest bidder !

[brucev]

Back in 2007 I made the mistake of buying a Chinese knock-off. It said it was a Coleman but it only lasted one trip before it sucked a valve. It was also loud. I replaced it under warranty and promptly sold it for a loss and bought a Yamaha ef2400i that is still working. Cost is always a concern for me but sometimes being cheap (frugal) is anything but cheap.