On Thursday 17 April 2014 11:32:36 Viesturs Lācis did opine: > Hello! > > I have three chinese servo drives in the waterjet machine and they are > constantly faulting with "overvoltage" error. Since I have not yet added > any braking resistors, it seems obvious that I should do so. > The question is: how do I determine appropriate resistance and rated > power values for the resistor? > Motor parameters are here: > http://www.cutting.lv/fileadmin/user_upload/tg-motor.pdf > > Currently max current in motors is set to 1,4A, which makes me think > that actual motor power is 500W. > Experienced guy suggested braking resistor with 100-150 ohm resistance. > But how do I determine correct rated power? Or is it that I just take > the biggest power available as it cannot be too high?
The latter here. I am using much lower R's than that, and there would be a limit to how many strokes I can use for a g33.1 on my lathe. But its more than a single usage to tap a hole would need. My resistors are 6 of the 20 watt 8 ohm power r's from the shack, and do get warm. The high speed set (I stage them with a wcomp module) loads a 1hp treadmill motor with a 2x2 network, giving 8 ohms & 80 watts, sandwiched between some alu angle, then as the speed dies it drop to 4 ohms at 40 watts air cooled, with the last stage being a dead short from about 125 spindle revs to stopped. Two reasons for the application staging, 1. don't exceed the motors nameplate or circuit breaker amps for fear of damaging the PM field magnets, and 2. Don't unscrew the fan/pulley from the motor shaft. It is loctite'd in place and screwed on much tighter than factory, but since its 3 or 4 lbs of iron, could rip up things in the box very easily should it come loose. > Viesturs > ------------------------------------------------------------------------ > ------ Learn Graph Databases - Download FREE O'Reilly Book > "Graph Databases" is the definitive new guide to graph databases and > their applications. Written by three acclaimed leaders in the field, > this first edition is now available. Download your free book today! > http://p.sf.net/sfu/NeoTech > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene -- "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> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/NeoTech _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
