Pete.
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Following on from Domeo_Jones' thread and from this previous thread of mine I thought I'd show how you can power a small 3-phase motor, forward and reverse off single phase just using a capacitor and 2-way switch. This is quite inefficient but works great for geared motors because the reduction gearing keeps the motor load very small.
Here's a 250w gear motor I have. It can be wired for star or delta, here it is in star which should be 415v but it works just find and I can't even slow the thing down.
Here's the setup. Take two phases and put a capacitor across them (not an electrolytic capacitor). A motor starting cap is fine, maybe even one of those out of a tube lamp. I used a 16uF because it's the first one I found.
Now you need a switch to put power down one of these two phases connected to the capacitor. Doesn't matter if you use live or neutral to the switch. The other mains power goes to the winding left on it's own.
I got it cobbled-up here. Live comes in and goes straight down the black phase. Neutral to the 2-way momentary switch and splits between the other two for fwd/reverse. The capacitor takes care of the spare leg:
So does it work? Course it does!
https://www.dropbox.com/s/prax1929im86wib/gearmotor on single phase.mp4?dl=0
Here's a 250w gear motor I have. It can be wired for star or delta, here it is in star which should be 415v but it works just find and I can't even slow the thing down.
Here's the setup. Take two phases and put a capacitor across them (not an electrolytic capacitor). A motor starting cap is fine, maybe even one of those out of a tube lamp. I used a 16uF because it's the first one I found.
Now you need a switch to put power down one of these two phases connected to the capacitor. Doesn't matter if you use live or neutral to the switch. The other mains power goes to the winding left on it's own.
I got it cobbled-up here. Live comes in and goes straight down the black phase. Neutral to the 2-way momentary switch and splits between the other two for fwd/reverse. The capacitor takes care of the spare leg:
So does it work? Course it does!
https://www.dropbox.com/s/prax1929im86wib/gearmotor on single phase.mp4?dl=0