Battery Back up

[johnnydoughey]

Hi Guys...
I am running stepper motors on my CNC router and am wondering just what kind of back up power would work during brown/back outs and glitches. I've had several electrical glitches and my machine has missed steps. Have any of you had luck with the APC or Cyberpower back ups (sold at Best Buy)? I just do not know if they would kick in fast enough to help...
Thanks much

[bowber]

I use UPS's for a large printer with heaters and a cutter and both seem to be fine with brownouts or flickers, I live and work in a rural area of the UK so the electric supply isn't always that reliable.
I also used to run my CNC on the one that's on the printer but I never experianced a power out with it on.
I think as long as you have a good quality one then it'll do the job, make sure you get one that's large enough to power equipment.

Steve

[apache405]

When buy the UPS, make sure you buy one that's big enough for your load. I would get something that can handle 1.8kVA (this will make sure a machine consuming 15A at 115Vac is feed enough power during a blackout without damaging the power inverter in the UPS) for whatever runtime you desire.

BTW: VA and Watts aren't the same unit. Take a look at the Wikipedia articles on AC power for a good explanation of the differences (AC power - Wikipedia, the free encyclopedia).

[DonFrambach]

I've been doing very long runs of up to 20 hours with my small router. The power we have in my area is fairly reliable but we occasionally get a flicker that sets off the UPS that I use with my office computer. I've worried about a long run being ruined by one of these power glitches.

For that reason, I incorporated an old APC UPS that was not being used after my son left for college. It's rated for 900 watts and my control computer, box, and spindle use about 450 watts (measured with a "Kill-a-Watt" device").

Here's a link to the posting on my build thread that shows the UPS in place: New DYI Fixed Gantry Router Build

Interestingly, when I remove power, the computer and my steppers run fine. The spindle continues to run but at full speed rather than the speed I have selected. I assume that's because the old UPS does not make a true sine wave and this confuses the spindle control electronics. I've ordered a new UPS that supposed to make a better sine wave (http://www.pcconnection.com/IPA/Shop...617&cac=Result) and hope that the spindle will work properly with that. Interestingly, when I went to Fry's to purchase a UPS they didn't have the "pure sine wave" version of the UPS but only a slightly cheaper version.

[DonFrambach]

The Cyberpower 1500VA 900W "pure sine wave" UPS came from PC Connection yesterday. Charged it up today and tested it tonight. With my Kress spindle cutting air, the Kress spindle speed remained unchanged when the 110 volts to the UPS was removed. To my surprise, the UPS reported that it had enough battery life to run my system this way for 25 minutes. I think this UPS will work fine for me!