Hi E2M
 I've played around with RVs - I've 2 x 2Hp motors, and I'm looking for a big 10Kw+ one.  (there are 2 15Kw ones on ebay atm - they weigh 92 Kgs each - £200... very tempted...) 3 phase motors are awesomely cool, and Mr Tesla was very awesome for inventing them.

Both my motors will run at designated speed on about 4 watts of power. I would expect a really big one to need maybe 10-15 watts.

You * absolutely have to have * a capacitor switch box. It's not possible to investigate the effect without one. I bought my (450v motor run) caps all new - it cost about £50. I used 4-gang light switches, and a rectangular plastic planter to put it in.

I really doubt you need to fear for your life at this stage mate. If it is OU - it's not obvious - lots of people have tried... It is fun, though, and you shouldn't stop having fun.

The reason the power usage goes down when you connect the light is maybe due to power factor correction? Or it's maybe because the total resistance is increasing? Either way - 73 watts is a lot of input power...

Also - you really need the variac going too. My RV's run happily on about 20v.

I've been looking at variable inverter drives. £90 on ebay... Trouble with those is you can't vary the voltage. Also, I've a feeling they might blow up if you try to use just one phase...

I've been thinking about building my own single-phase variable drive - using a tank-circuit in a switchbox with variable inductance and capacitance, and a ZVS driver and 12v batteries...

I currently need a decent drive system for testing out generators - maybe using an RV... I'm building a few VAWTs to put around the place, and I've bought a couple of cheap DC motor / generators to use. I want to test 'em out before I install them...

Regards
Tim

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