On Wednesday 23 December 2020 08:33:16 Todd Zuercher wrote: > I doubt you'd really need a braking resistor for running a router > spindle (what I believe you have.) Simply test it without one, as > long as you don't get overvoltage alarms on the VFD when decelerating > you should good without it (assuming your VFD has adequate safety > alarms which might be a big assumption with a Chinese piece.) I've not > run into a machine that uses one myself, but I only work with large > commercial router machines. (not any mills or lathes) and router > spindles don't have the rotating inertia that other machines like a > lathe might or the need to stop super fast. > Consider this Todd, 2 smaller 1.5 kw vfd clones, also by HY, have no braking R at all, yet its overshoot at reversal is under .25 turns at 100 rpm while reversing a 40 lb chuck on the Sheldon. And I've set the min_speed of the motor I'm taking off at 4k revs and can sit there, m3-m4 and back and its just a few millisecs to the requested speed in the new direction. No complaints from that 110 volt vfd although an overhead led light does blink a little. Both of those vfd's are set to not exceed the motors nameplate FLA. But now I've run a separate 250 volt line to this vfd so I doubt the led strip over the bed will blink.
There is a table in this vfd's booklet I just found that says 70 ohms at 300 watts s/b used. I'll have to procure that however, Generally, I've found that if the vfd offers DC braking, its adequate. And I believe it does. We'll see but this one won't be doing any rigid tapping either so it shouldn't matter that much. Thanks Todd. 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) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
