sa100
Hot Rolled
- Joined
- Mar 12, 2008
- Location
- suburban detroit
Hello everyone,
I bought a large saw that has a 5HP, two speed, three phase motor that runs on 440v only. I'd like to run the saw on single phase 220 and am unsure how best to go about it. Here are some constraints and (hopefully) helpful information:
1. The motor is special and can't be replaced easily.
2. The saw has a dual contactor setup similar to that used on reversible drill presses, etc. to engage the appropriate windings. Based on this, I believe that the motor has two separate sets of windings not the reconnectable wires like the smaller two speeds/two hp's motors commonly used on drill presses.
3. The saw is also equipped with a "shortstop" electronic brake which I'd like to keep but would remove if necessary.
4. This is a 16" table saw with a direct drive motor so the starting load isn't very high.
5. I don't want to rewind the motor.
I bought a three phase autotransformer with the intention of using it to run this saw. The autotransformer has taps for every imaginable voltage, including the ones I need. I did a quick and dirty connection with the autotransformer and my capacitor box to see if the thing would run at all and it wouldn't, it only hummed on "high" speed and wouldn't even engage on "low" speed. I regularly use the capacitor box to start 5HP 220v motors, so I don't think too little capacitance is the cause.
So my question to the community is, how do I make this thing run? What are my options? I prefer some sort of static solution, but I'm not against the idea of building a rotary phase converter if need be. I also have a 220V 10HP 3 phase VFD that runs conventional 5HP 220V motors without complaint from my single phase lines, but I believe that VFD's don't like transformers, and I am very reluctant to experiment with that expensive VFD.
btw, I'm sure that a valid answer would be that there are commercial units available that would solve this dilemma perfectly. But I'm sure those units would cost several times what I paid for the saw, and spending large amounts of money violates my code of ethics (as well as my bank book). I'd rather build something myself if at all possible.
All suggestions welcome and appreciated. Thank you in advance for your consideration.
Steve
I bought a large saw that has a 5HP, two speed, three phase motor that runs on 440v only. I'd like to run the saw on single phase 220 and am unsure how best to go about it. Here are some constraints and (hopefully) helpful information:
1. The motor is special and can't be replaced easily.
2. The saw has a dual contactor setup similar to that used on reversible drill presses, etc. to engage the appropriate windings. Based on this, I believe that the motor has two separate sets of windings not the reconnectable wires like the smaller two speeds/two hp's motors commonly used on drill presses.
3. The saw is also equipped with a "shortstop" electronic brake which I'd like to keep but would remove if necessary.
4. This is a 16" table saw with a direct drive motor so the starting load isn't very high.
5. I don't want to rewind the motor.
I bought a three phase autotransformer with the intention of using it to run this saw. The autotransformer has taps for every imaginable voltage, including the ones I need. I did a quick and dirty connection with the autotransformer and my capacitor box to see if the thing would run at all and it wouldn't, it only hummed on "high" speed and wouldn't even engage on "low" speed. I regularly use the capacitor box to start 5HP 220v motors, so I don't think too little capacitance is the cause.
So my question to the community is, how do I make this thing run? What are my options? I prefer some sort of static solution, but I'm not against the idea of building a rotary phase converter if need be. I also have a 220V 10HP 3 phase VFD that runs conventional 5HP 220V motors without complaint from my single phase lines, but I believe that VFD's don't like transformers, and I am very reluctant to experiment with that expensive VFD.
btw, I'm sure that a valid answer would be that there are commercial units available that would solve this dilemma perfectly. But I'm sure those units would cost several times what I paid for the saw, and spending large amounts of money violates my code of ethics (as well as my bank book). I'd rather build something myself if at all possible.
All suggestions welcome and appreciated. Thank you in advance for your consideration.
Steve