> -----Original Message----- > From: Viesturs Lacis [mailto:[email protected]] > Sent: Sunday, November 06, 2011 5:13 AM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] Dust-proof case? > > Dave, Kirk, Jon, thanks! > > 2011/11/5 Dave <[email protected]>: > > > > What I did to verify that the VFDs were the problem was to run the > > machine without the VFD powered up - pull the fuses or unwire them.. > > Then try running parts for an hour or so. Remove the cutters if need > > be.. . If the problem vanishes you likely have an VFD > related noise problem. > > It is easy to switch the VFD off, but I am having difficulties to come > up with a plan, how to check, if the tool takes correct path. I will > consult with client's specialists - maybe they can suggest something. > > 2011/11/5 Kirk Wallace <[email protected]>:>> My experience > seems to indicate:>> _Always_ have a filter on VFD power inputs. > > I have a question here: > Filters on VFD input lines have been mentioned several time here. Is > this something close to what is meant here: > http://www.newark.com/tyco-electronics-corcom/10vr6/rfi-power- > line-filter-10a-700ua/dp/52K3303
Viesturs, When choosing a filter for the mains power into the VFD, be sure to choose one with a large enough current rating to supply the VFD safely. Your VFD manual should give a rating for the input power source. Do not try to use this type of filter on the output of the VFD. These filters are designed to operate on power that has 50 or 60 Hertz as the fundamental frequency. The output of a VFD will have the inverter frequency (usually between 2,000 and 20,000 Hertz) as its dominant frequency. A motor does not mind because it is an inductive load and will act as its own filter. The interference filter will have capacitors to ground and depending on filter design, these may see much more current than they are designed to handle when the fundamental frequency is above 60 Hertz. There are filters designed for use on the output side of a VFD, but they are larger and more expensive. These are usually sold by the VFD manufacturer. For cost reasons it is usually more practical to try to shield the VFD output by using conduit or a shielded cable. Also note, this is one case where the shield of the cable should be grounded at both ends, unlike most cables that carry signals instead of power. Steve Stallings > > 2011/11/5 Jon Elson <[email protected]>: > > > > You can run memtest86 from the install CD and let it run > for at least > > several > > hours. This program gets the CPU warmed up and exercises memory > > heavily. If it finds even a single error, don't bother with > anything else > > until it can run without error overnight. > > > > Also, you can run the latency test for a few hours, and exercise web > > browsers, USB memory stick inserts/removals, glxgears and other > > operations to see if the latency gets bad. > > I ran latency test with glxgears and tried to open/close firefox last > time I was there. But I think that I ran the test for 15-20 minutes. > It was pretty fine - max jitter on base-thread was reaching 25000 ns, > but base thread is not used and max jitter on servo thread was around > 16000 ns, servo period is standard 1 ms. > I recall that I ran latency tests, when I initially installed EMC2 on > the machine and there were cases, when max jitter reached >800K ns - > almost another servo period. Also that time I ran the test for less > than 15 minutes. > I will try to figure out, how can I these tests for longer time period > without sitting next to the machine - it is several hours to drive > from my place. And I think that client will not be happy about machine > idling for a whole working day, but I will handle that. > > Viesturs > > -------------------------------------------------------------- > ---------------- > RSA(R) Conference 2012 > Save $700 by Nov 18 > Register now > http://p.sf.net/sfu/rsa-sfdev2dev1 > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
