Rick56 (Customer) asked a question.
Does anyone have any experience using battery powered inverters (E.g.; 12 Vdc --> 220 Vac) to power a GS2 VFD (or similar) in a loss of utility power scenario? I would like to know if there have been any issues either with the inverter or the VFD/motor or did everything function normally. I am concerned that no matter how good the inverter is, it will never produce a pure sine wave and will this affect the VFD or conversely, will the switching nature of the VFD causing problems for the inverter. I currently power a GS2-20P5 VFD from 220 Vac ("split phase") going through a LR2-20P5-1PH line reactor in series with a 20DRT1WGS EMI filter. AD tech support or inverter reps had no advice. Thanks in advance.
I haven't tried it myself, but...
The VFD just converts the incoming AC to DC before it does anything with it so I wouldn't think waveform would make much difference. Might possibly have some effect on the diode temperature and possibly capacitor life but I wouldn't expect it to be too significant.
As far as the UPS, it might be seeing a fairly large inrush if you switch the power to the drive on while on the UPS, but the 20P5 is not a large drive so I wouldn't really expect that to be a huge problem. and because of the relatively large capacitors in the VFD the high frequency switching of the VFD probably won't really be seen by the UPS, at least not at any significant current, there will be "noise" but so many things have switching power supplies now I'd expect any competent UPS to handle it..
I agree. I doubt anyone at AD would go on record saying it would work. I won't even go record saying that, and I have nothing to lose. But I will say that I wouldn't be afraid to try it, and I would try it fully expecting it to work. VFDs are built to withstand spikes, transients, overvoltage, undervoltage, all manner of suboptimal conditions caused by the motors they power. You can typically power a VFD from a DC source no problem. I think if anything is being risked by giving it a shot, it's the inverter. Is it an expensive inverter?
Tinker, strantor2; Thanks for the feedback. I suspect you are both correct and I'm just overthinking this. But recently, in my wanderings on the 'net, I read something about some inverters not liking certain types of equipment (things with switching circuitry, I think), it might have been a CPAP machine and it's OEM saying that you MUST use THEIR inverter or bad things might happen (it wasn't clear what). Might have been a scare tactic to sell there own overpriced inverter.
In any event, I use this VFD for opening a large door on an outbuilding I have and was looking into powering the VFD (and PLC, I got carried away on this project) via a car or tractor battery in case I wanted to move the door in the event of a power loss. I was just hoping to hear from someone that may have actually done this before I drop $200-300 on an inverter.
What loads today don't have switching circuitry? Almost everything is SMPS now. UPS are often sold as a PC backup. What's in a PC? SMPS. You won't regret owning a multi-kw inverter even if it isn't compatible with the VFD.
Can't 'We' just run 20 to 24 12 Volts batteries in Series and have them sit on the DC Bus?.. Think you'd want to do Better DC Buss Voltage Checks to get a more accurate Voltage reading before you hook up..
I'm not sure how successful it'd be.. And Battery Float Charge would be a Concern.. Diode In the Discharge Direction, with a Parallel Resistor on the Charge Direction the Limit Charge Current?
Who wants to be the First to Try it?.. Fuse Protection and Blast Shields..
Cap
Why yes, you can do just that. Everyone's favorite foul mouthed YouTube star, AvE, has done so in a super sketchy proof of concept right here:
https://m.youtube.com/watch?v=p9R1YLo8g3E