Is the 12V side any good? Run a bigger inverter off that?
What engine experiment to run on this generator?
- Thread starter skyactiv
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100 hp shot of nitrous!
I'm surprised nobody has mentioned that [censored] meter you were measuring with. They don't have anything close to actual RMS measurement circuits, so they estimate based on a flawless sine wave. It takes very little distortion in the sine to get that meter to grossly over-read (I have 5 of them for disposable jobs but I don't use the AC measurement for anything closer than go/no-go and neither should you). 110V RMS is about 155V peak. That meter is reading less than that, but you are guessing wildly if you want to use that to try and ascertain the *real* output voltage.
Get (beg, borrow or buy) a meter with a decent RMS circuit and try again. Also, what everyone else said. Governor speed & load.
Get (beg, borrow or buy) a meter with a decent RMS circuit and try again. Also, what everyone else said. Governor speed & load.
Oh yeah, I didnt even think of that. Yeah, try a True RMS meter and I bet you will get a different result.
I saw the cheap meter, but I was reluctant to pile on. I almost posted that he should check the frequency, but that's obviously not happening with the meter pictured. I have a Kill-a-Watt meter that shows frequency as does my Fluke meter.
Rotating machinery usually has a fair wave form, but who know about that little genny. That the OP tried using such a generator to run a sump pump says a lot about his knowledge level.
Rotating machinery usually has a fair wave form, but who know about that little genny. That the OP tried using such a generator to run a sump pump says a lot about his knowledge level.
Yeah, 1000 watts...A little over 8 amps. According to Engineering Toolbox, 1/3HP motor on 115VAC is gonna pull over 7 amps. 1/2HP is gonna need almost 10 amps. Some motors are more efficient than others, but that should ballpark it. So if his sump pump is anything more than 1/3HP it won't run it.
Originally Posted By: Colt45ws
Yeah, 1000 watts...A little over 8 amps. According to Engineering Toolbox, 1/3HP motor on 115VAC is gonna pull over 7 amps. 1/2HP is gonna need almost 10 amps. Some motors are more efficient than others, but that should ballpark it. So if his sump pump is anything more than 1/3HP it won't run it.
And that is only talking of steady state. Motor start current can be up to nearly an order of magnitude greater. Most inverters/generators rated to run induction motors have a massive short term surge rating to get the motor started. Those that don't either pop a breaker, stall or drop the output voltage way past the point of usefulness and eventually either smoke the generator or motor.
I've had a 2500W generator that would not start a 1000W compressor but would drive a 2500W fan heater all day long. Measured estimates for start current were in the order of 5 x steady state running current on that device, and that was only a little one.
Originally Posted By: Joshua_Skinner
Rotating machinery usually has a fair wave form, but who know about that little genny. That the OP tried using such a generator to run a sump pump says a lot about his knowledge level.
Agreed, but it does not take much of a wave form error for the non-RMS meters to give wacky readings, and inductive machines don't tend to give nice sinusoidal waveforms into an open circuit. You get all sorts of peculiar distortions. Put a 20W light bulb on it and it'll settle down and look much more reasonable.
Yeah, 1000 watts...A little over 8 amps. According to Engineering Toolbox, 1/3HP motor on 115VAC is gonna pull over 7 amps. 1/2HP is gonna need almost 10 amps. Some motors are more efficient than others, but that should ballpark it. So if his sump pump is anything more than 1/3HP it won't run it.
And that is only talking of steady state. Motor start current can be up to nearly an order of magnitude greater. Most inverters/generators rated to run induction motors have a massive short term surge rating to get the motor started. Those that don't either pop a breaker, stall or drop the output voltage way past the point of usefulness and eventually either smoke the generator or motor.
I've had a 2500W generator that would not start a 1000W compressor but would drive a 2500W fan heater all day long. Measured estimates for start current were in the order of 5 x steady state running current on that device, and that was only a little one.
Originally Posted By: Joshua_Skinner
Rotating machinery usually has a fair wave form, but who know about that little genny. That the OP tried using such a generator to run a sump pump says a lot about his knowledge level.
Agreed, but it does not take much of a wave form error for the non-RMS meters to give wacky readings, and inductive machines don't tend to give nice sinusoidal waveforms into an open circuit. You get all sorts of peculiar distortions. Put a 20W light bulb on it and it'll settle down and look much more reasonable.
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