On Sunday 13 March 2016 13:36:58 Jon Elson wrote: > On 03/13/2016 08:03 AM, Gene Heskett wrote: > > On Sunday 13 March 2016 07:40:25 John Thornton wrote: > >> On my GS-2 with the braking resistor I go from 1800 fwd to 1800 rev > >> in 1 second. I have both acceleration and deceleration set to 1/2 > >> second. > >> > >> JT > > > > That would be considerably more usefull than the controllers default > > of 30 seconds. Do you recall the specs of the resistor you used? > > Take the line current rating of the motor, multiply by 1.7 > (to make it "single phase current" then multiply by 1.5-2 > for a peak current rating. Now, compute 340 / (number > calculated above) and that is your resistor value. These > are rough calculations, but when the drive's controller > detects a high bus voltage it will turn on the braking > transistor until the voltage is safe again. So, the > resistor will be pulsed on in short bursts as needed during > braking. Use a big vitreous enamel resistor, it will only > be pulsed during braking, so doesn't need to carry the > steady-state wattage of that resistance across 340 V DC. I > used a single 25W resistor on my Bridgeport, and a pair of > 50 W resistors on my VFDs. The Bridgeport resistor does get > hot when rigid tapping many holes, the one on the lathe > never does, but it is not CNC'd so no rigid tapping on that > machine. > > If you can find a chart of braking resistors in the book, > use that instead of my scheme. > > Jon
Well, I like your idea better if the resistor switching is smart enough to do that, but first I am going to have to take it all apart and see if I can find terminals P & B that are called out on the interface pages, but are no-where to be seen on the power input and motor output terminal strip under the front cover. If I open it all the way up, and find a place for a big transistor thats empty, I'll know I bought a real pig in a tied shut poke. In that case it would make a good driver for a gantry router setup, but worthless as the tits on a boar hog to me. I'll put some shoes back on and go get it and some diss tools & see if I can get any smarter. Right now I am beginng to feel a little dumb for buying it. More later I expect.... Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
