Induction motor start current and inverters

[frackers]

Greetings

I'm in the process of putting together an axial wind generator with a view to driving the filter and solar circulation pumps on my pool. The idea is to avoid the initial cost of too large a battery bank as most of the power I can use as its generated (i.e. at night I run the filter, in the day I run the solar circulator if the panel is warm enough otherwise run the filter).

I'm trying to get to grips with the specs for the pump motors which are 1HP, 750W, 6amp max and as far as I can find out the startup current is up to 30amps. I'm looking at a 2500W inverter which will happily run both pumps but I doubt it will start either!

Is there a simple soft start circuit I could use?

I'm on 230v supply here in NZ so I've a made a back-of-a-fag-packet calculation that a series resistance of 15ohms will limit the start current, after a second or so a timer relay shorts it out to bring the motor up to full power. Does this sound feasible?

Cheers

[stephent]

If that would allow the motor to start spinning a bit--maybe..

but look at the resistance wattage required. (I^2 x R)

Might be better to use a motor start or run capacitor to do what you want instead of a resistor. Even then it would have to be a quick delay time.

A lot of the old time resistance softstart controllers used ni-chrome wire for a resistor.

[Gary D]

Would it be cheaper or feasable to replace the AC motor with a 1 hp. DC motor rated at the desired speed/voltage? You could do away with the inverter losses completely... Just a dumb thought, seems to be too easy, but,if close enough to the battery bank and fused correctly?...

 Gary D.

[asheets]

I'd think what you'd need is a timer of some sort...  one that can detect adequate wattage at the gen, wait 60 seconds, then fire up the motors at the pool.