Hey folks.
This is an update on my project to build a rotary phase converter.
I bought a 36" bandsaw at an auction and it needs 550volt 3 phase power. I bought a 5hp 575 volt motor and a transformer to boost my 240volt line power to 570 volts.
I assembled my main panel with start and run capacitors (red and blue tags), 600 volt contactors and the hookups.
My first attempt to start the idler failed as I had the start caps wired to T1 and T2 instead of T1 and T3.
After that was fixed I threw the main switch which powers the transformer, the 110 volt switch that closed the contactor powering T1 and T2 at 570 volts and the monentary switch that brought the start caps online.
The 5hp idler motor started in less than a second and ran smoothly.
Unfortunately the run caps were not in the circuit when I tested.
Voltages on the 3-phase output were:
T1 to T2 554
T1 to T3 460
T2 to T3 466
Amperage Draws were:
Line to transformer (240v) 6.6
High side (570v) 2.3
I patched in the bandsaw and it started without drama and ran smoothly. I cut some hardwood with it and it worked perfectly however I noted some slight noise from the motor when ripping some 2 by.
With the saw idling the line in was drawing 23 amps and the high side 9.6 amps.
Qoustion: Can I balance the voltages better with the start caps?
Also I was under the impression that the caps did not store energy (at least much) when operating on AC power. This misconception was dispelled when I touched my finger to a terminal accidentally. I touched the terminals with leads from a 100watt spotlight I had handy to drain the caps down and it smoked the bulb instantly and I had a fat, blue spark when I touched the lead to the terminal.
Sorry for the long post but I am pleased and excited that I can see progress in this project.
As always comments pro and con are welcomed.
Brad
This is an update on my project to build a rotary phase converter.
I bought a 36" bandsaw at an auction and it needs 550volt 3 phase power. I bought a 5hp 575 volt motor and a transformer to boost my 240volt line power to 570 volts.
I assembled my main panel with start and run capacitors (red and blue tags), 600 volt contactors and the hookups.
My first attempt to start the idler failed as I had the start caps wired to T1 and T2 instead of T1 and T3.
After that was fixed I threw the main switch which powers the transformer, the 110 volt switch that closed the contactor powering T1 and T2 at 570 volts and the monentary switch that brought the start caps online.
The 5hp idler motor started in less than a second and ran smoothly.
Unfortunately the run caps were not in the circuit when I tested.
Voltages on the 3-phase output were:
T1 to T2 554
T1 to T3 460
T2 to T3 466
Amperage Draws were:
Line to transformer (240v) 6.6
High side (570v) 2.3
I patched in the bandsaw and it started without drama and ran smoothly. I cut some hardwood with it and it worked perfectly however I noted some slight noise from the motor when ripping some 2 by.
With the saw idling the line in was drawing 23 amps and the high side 9.6 amps.
Qoustion: Can I balance the voltages better with the start caps?
Also I was under the impression that the caps did not store energy (at least much) when operating on AC power. This misconception was dispelled when I touched my finger to a terminal accidentally. I touched the terminals with leads from a 100watt spotlight I had handy to drain the caps down and it smoked the bulb instantly and I had a fat, blue spark when I touched the lead to the terminal.
Sorry for the long post but I am pleased and excited that I can see progress in this project.
As always comments pro and con are welcomed.
Brad
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