Inverter advice

[KantSnyer]

On a 0.37kw motor I very much doubt that! With what instrument did you measure it? A regular meter will not be able to measure the inrush current, only fancy Flukes and the like can do that.

This is a 0.37kw motor and startup current is 16A !!

https://inverterdrive.com/group/Single-Phase-Motors/TEC-Single-Phase-Motor-370W-2800RPM-HST-71F-B3/

View attachment 1391767

Indeed, here's the specs for the OP's pump

 

[wingnut771]

It tries to match the waveform close as possible of course, but it isn't perfect.

View attachment 1391761

That is also why a 5kw inverter can't push 5kw to grid for instance. I think the best case is around 75% efficiency.

That is also why not every mediocre inverter is allowed to be grid tied. They're typically of higher standard and also much more expensive.

Why are you posting modified sine wave pics?

 

[Lupus]

It tries to match the waveform close as possible of course, but it isn't perfect.

View attachment 1391761

That is also why a 5kw inverter can't push 5kw to grid for instance. I think the best case is around 75% efficiency.

That is also why not every mediocre inverter is allowed to be grid tied. They're typically of higher standard and also much more expensive.

That is modified sine wave, which is another form of inverter, you do get pure sinewave

 

[$m@Rt@$$]

Why are you posting modified sine wave pics?

That is modified sine wave, which is another form of inverter, you do get pure sinewave

That is for illustration. 'Modified' sinewave is a poor-ish quality waveform. Higher quality inverters simply have more capacitors increasing the number of steps it takes to simulate the AC waveform and thus decreasing those jumps getting closer to the waveform of an actual mechanical generator spinning.

So once again, no, you cannot get pure sinewave from an inverter. If you know how inverters invert DC to AC and have a reasonable scientific mind, you'd realise it's practically impossible.

 

[wingnut771]

That is for illustration. 'Modified' sinewave is a poor-ish quality waveform. Higher quality inverters simply have more capacitors increasing the number of steps it takes to simulate the AC waveform and thus decreasing those jumps getting closer to the waveform of an actual mechanical generator spinning.

So once again, no, you cannot get pure sinewave from an inverter. If you know how inverters invert DC to AC and have a reasonable scientific mind, you'd realise it's practically impossible.

Thanks, but at the end of the day, a pure sine wave inverter works just fine running motors and synchronising with the grid so the "issue" is a moot point imho.

 

[$m@Rt@$$]

Thanks, but at the end of the day, a pure sine wave inverter works just fine running motors and synchronising with the grid so the "issue" is a moot point imho.

100% agreed. Like I said originally, it was just an FYI. Just another sort of false marketing thing to look out for because what one manufacturer considers pure isn't pure for another

 

[x7razor]

How can 2.1A have less watts than 1.3A?

230V x 2.1A = 483W

On a 0.37kw motor I very much doubt that! With what instrument did you measure it? A regular meter will not be able to measure the inrush current, only fancy Flukes and the like can do that.

This is a 0.37kw motor and startup current is 16A !!

https://inverterdrive.com/group/Single-Phase-Motors/TEC-Single-Phase-Motor-370W-2800RPM-HST-71F-B3/

View attachment 1391767yeah all i have here is one of those kilowatt meters from geewiz and that is what is displayed . Will see if i can test it next week with the works stuff

Thanks for the input