MDNick
Gold Member
Re: 220 volts/230 volts/ 240 volts: What\'s the diff?
Okie,
No, I don't know of a good source. Everyone I know builds there own. MUCH cheaper than what they can be bought. Your motor won't work. You need a 3 phase motor. /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif
I knew I was going to wind up explaining this. You don't so much power a phase converter as make 3 phase with a 3 phase motor. With a 3 phase motor, you power it with 220 2 phase (this is what residential 220 is, 2 110V legs 180 out of phase with each other, industrial 220 is single phase, only 1 220 leg.) Using appropriately sized capacitors, you adjust the phase (capacitors take time to charge and discharge) so by connecting them to the 110 legs, you can adjust the phase time. One of the legs powers 2 motor leads, one connection straight to the motor, the second through a capacitor to adjust the phase time by 120 degrees. The second 220 leg is run through a second capacitor, to adjust its time by 60 degrees. This all has the affect of creating 3 legs that are 120 out of phase with each other. The motor is just used as a place for the juice to go, because if you don't have current flow, the capacitors don't do their thing. That is why the rotary phase conveters are so effecient. The motor just idles. The 220 is in fact pulled off prior to or at the electrical connection to the motor.
The selection for the motor rule is size it the same HP as the largest HP load, then you can power twice the HP load from it. What I don't understand with that rule is, why can't I only power one thing, and have the phase converter be 1/2 the HP of that load. Can't explain that one. /forums/images/graemlins/confused.gif
If you can find a 3 phase motor, you are a good ways towards making a phase converter. The actual selection of appropriately sized capacitors will require help from someone else. I have 2 friends that are quite good at it. When I get around to building mine, I am going to seek their counsel. If you don't know someone that can help you out, you may be stuck buying one. Unfortunately, $400-$500 for a 2 hp unit. And the heck of it is, you need a used old 3 phase 220 motor (free if you look in the right places) and about $20 in capacitors. And the knowledge to put it together. /forums/images/graemlins/wink.gifThat's the gotcha. Of course, when you buy one, you get a brand new motor. That's $200, retail. But it just sets there idling. They have the $20 (or less when bought in quantity) in capacitors, probably $150 or so in the motor. More than 100% profit /forums/images/graemlins/ooo.gif. Not bad. But they know how to build it, and most folks don't. /forums/images/graemlins/frown.gif
Nick
Okie,
No, I don't know of a good source. Everyone I know builds there own. MUCH cheaper than what they can be bought. Your motor won't work. You need a 3 phase motor. /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif
I knew I was going to wind up explaining this. You don't so much power a phase converter as make 3 phase with a 3 phase motor. With a 3 phase motor, you power it with 220 2 phase (this is what residential 220 is, 2 110V legs 180 out of phase with each other, industrial 220 is single phase, only 1 220 leg.) Using appropriately sized capacitors, you adjust the phase (capacitors take time to charge and discharge) so by connecting them to the 110 legs, you can adjust the phase time. One of the legs powers 2 motor leads, one connection straight to the motor, the second through a capacitor to adjust the phase time by 120 degrees. The second 220 leg is run through a second capacitor, to adjust its time by 60 degrees. This all has the affect of creating 3 legs that are 120 out of phase with each other. The motor is just used as a place for the juice to go, because if you don't have current flow, the capacitors don't do their thing. That is why the rotary phase conveters are so effecient. The motor just idles. The 220 is in fact pulled off prior to or at the electrical connection to the motor.
The selection for the motor rule is size it the same HP as the largest HP load, then you can power twice the HP load from it. What I don't understand with that rule is, why can't I only power one thing, and have the phase converter be 1/2 the HP of that load. Can't explain that one. /forums/images/graemlins/confused.gif
If you can find a 3 phase motor, you are a good ways towards making a phase converter. The actual selection of appropriately sized capacitors will require help from someone else. I have 2 friends that are quite good at it. When I get around to building mine, I am going to seek their counsel. If you don't know someone that can help you out, you may be stuck buying one. Unfortunately, $400-$500 for a 2 hp unit. And the heck of it is, you need a used old 3 phase 220 motor (free if you look in the right places) and about $20 in capacitors. And the knowledge to put it together. /forums/images/graemlins/wink.gifThat's the gotcha. Of course, when you buy one, you get a brand new motor. That's $200, retail. But it just sets there idling. They have the $20 (or less when bought in quantity) in capacitors, probably $150 or so in the motor. More than 100% profit /forums/images/graemlins/ooo.gif. Not bad. But they know how to build it, and most folks don't. /forums/images/graemlins/frown.gif
Nick