I saw something on SBE's website (app notes) stating somewhat different numbers, depending on the application. For example, 3 phase, single phase, or pulse applications. I suppose your real quote from an engineer is the best we can hope for!
The numbers I was calculating were sine waves, phase to neutral, and with my motor, it would be impossible to measure those values. (Actually, I'm not sure if the neutral is connected to ground)
Thanks again; this is a huge help!
- E*clipse
Quote:
Originally Posted by MPaulHolmes
The beauty of those ring capacitors is, "occasional spikes over 600v are not a good reason to get a higher voltage ring cap." That's a quote from one of the SBE engineers. They were trying to push the 450v cap on me when I was going to run it at 300v. They don't need much derating at all.
The 3 phases to neutral are 120Vac. But I think that only makes sense when talking about filtered real life sine waves that are 120 degrees apart. Starting with DC, we are just getting pwm'ed square waves that instantaneously don't look like 120Vac from phase to neutral. They have to be filtered before looking like that.
EDIT: Or maybe it really is 120Vac sine waves, 120 degrees out of phase that are across each phase coil, but the phase coil voltage (to neutral) is not accessible to us. Sure, let's go with that! haha.
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