Now that we were moving towards a 3-phase product .... we needed the ability to test 3-phase. First problem was a 3-phase source of power. The Lab and The Shop are just a spare bedroom and the garage of my house and we have a 100A 240V service so we started hunting around.
After learning more than I ever wanted to know about phase converters, I found one that was reasonably affordable and bought it. A few notes in case you ever need to buy one:
- Don't fall victim to the 180 degree vs. 120 degree phase debate. The internet is awash with this dogma. The 240V that feeds a phase converter is single-phase (no common reference with a 2-wire feed) so the idler motor can make a true 120 leg. The voltage isn't always perfect on that artificial leg - and it's current response can lag a bit - but it's passable 3-phase power.
- Don't fall victim to the "solid state" or "idler free" phase converter. It's just a capacitor bank that functions as a starting capacitor that shifts the current of a motor's 3rd phase during starting then turns off .... leaving your motor to run on just two-phases. It works for motors (though reduces HP by 1/3) but it's a starting current nightmare and not something you'd want to test with.
We also needed a motor to use. We haggled and picked up a small 3-phase motor from a local surplus.
Here are our new babies: