I think this is the only practical solution possible.

I think that if you put a resistor in series with the inverter that would consume 200W, that you will draw 1200W from the battery. The inverter will increase input current to get to its 1000W (actually VA) rating (up to its max input current).

You would also lose constantly 200W, not the most efficient solution.

It is maybe possible to build a DC chopper that would limit the input power to 800W, but I don't think you could buy something like that. You would have to design/build it yourself (you would turn a switch (mosfet or something like that) quickly on and off while you constantly measure that you take only 800W from the battery).

Your best bet is to buy a inverter that has the possibilty to limit max output. Sell the unit you have now...



Why do you want to limit the 1000VA unit to 800VA?

thank you, someone
 Does he know what parts he was fixing?

I don't have this engine, a quick search at youtube found this:

Look at https://www.youtube.com/watch?v=XxZ78_d3Q1A around 1:26.
Also https://www.youtube.com/watch?v=s1QsNHWb70o around 0:05.
And https://www.youtube.com/watch?v=PI-BQMVtXU4 around 6:10.


Looks like there is nothing to fix (plug the hole)...

I would like to thank the people who make this website possible, to make the time, and spent the money, to keep the website online.

I don't post much, but I like to read, and learn here.

So: thanks!

You have a motor with 400V coils.

This means that in delta, grid voltage needs to be 400 volts. This is the "normal" grid voltage in a modern factory.

If you have a 690V grid, you would need to configure the motor in star (is not used).

This is a normal configuration for "new" motors. You can thus use a star/delta configuration to limit the startup currents on a 400V grid.

Asynchronos motor are ideal to use as generator while grid connected. Sadly, this is illegal (for safety reason) in most parts of the world.

It could be used not grid connected (delta configuration), if you have a constant load (in star configuration with 230V loads), like an electrical heater. This electrical heater could be a star configuration of eg 3 1 kW heaters.

Using this motor as generator, you NEED a balanced load across the 3 coils. The way an unbalance would be solved is here not available (the neuter line in the center of the star is used to solve the unbalanced loads). If you would use the motor as generator with a not balanced load (eg 1Kw, 2kW and 3 Kw heater) not grid connected, you would get eg 180V on 1 heater (not a big problem) 260V on another and maybe 290 V on the third (big problem).

If you would have 3 400V heaters, then you could put both generator and load in star configuration. You could then connect both centers of the star with a neuter line, and thus use an unbalanced load. This would give other problems, mainly overheating of the coil that has the largest load and cogging. Not advised, and also not so easy to get 400V monofase heaters.

Using an asynchrone motor as a grid tied generator, you don't need the capacitors. The grid supplies the needed reactive power. And the load is almost always balanced.
Using it standalone, you do need the capacitors. And when you change the load, you need to change the value of the capactor or the voltage and frequency would drift.

Some reading:
http://www.gohz.com/induction-generator-synchronization-with-grid#:~:text=The%20grid%20feeding%20powering%20the,will%20deliver%20power%20in%20sync.
https://www.qsl.net/ns8o/Induction_Generator.html
https://www.smokstak.com/forum/threads/induction-generator-from-synchronous-generator.20046/#post-89860
https://www.smokstak.com/forum/threads/motor-starter-for-induction-generation.161917/
https://www.survivalistboards.com/threads/homemade-induction-generator.24036/
https://www.mytractorforum.com/threads/induction-generator.91257/
http://users.telenet.be/b0y/

PS: Do this on your own risk. I'm not responsable if you get killed...