Cable shields are typically tied to frame/backplane ground. One end only if you want to avoid ground loops. The cable shield from your VFD to motor connection should also be tied to frame/backplane ground. I don't see a filter on the power feed to that GS2 VFD? Do you have one? The Automation direct single phase one is about $80 and worth every cent. Move your drive to motor cable to the right side of the drive and don't put it in that wire duct. Attach it to the side of the drive if you need to attach it anywhere. There is no requirement to have the 0V of your 5 or 24 volt supply tied to frame/backplane ground. I think that Automation Direct VFDs may also be sold as EMI generators. They push noise back into the power feed very effectively and I have seen that same noise go right through 5V and 24 volt power supplies and screw things up. I've fought that fight before and won.
In general the panel looks nice. Not excessively crowded. Dave On 12/10/2015 2:09 PM, Mark Johnsen wrote: > One question I had when wiring up the system is I connected the west amp > servo cable _shield_ to the backpanel. Which is also where the VFD is > attached and pretty much everything else would be grounded to that as > well. I was concerned about noise with that... > > Should I have attached that to 0Vdc. And, then I have 0vdc for the 5vdc, > 15vdc, and 24vdc power supplies. Ugh, this is a mess... > > https://goo.gl/photos/SMSGpyjStBL1dKjb6 > > I have nicely soldered extensions on the shields (Yellow shrink wrap). > Plus, you'll see my ebay Chinese ferrules on the wires into the 7i77 as > well... Nice... > > Thanks, > Mark > > On Thu, Dec 10, 2015 at 10:52 AM, Mark Johnsen <m...@ijohnsen.com> wrote: > >> I'm sure I have noise in my setup. >> >> Here's a picture of my cabinet, which I actually took time to route wires >> decently. >> https://goo.gl/photos/AogjAzWHpGGysceQA >> >> I did my best to keep things separated, but there was only so much room. >> I think my AutoDirect GS2 3HP vfd is probably too close to the 7i77, Also, >> the 80Vdc coming from the step down transformer and rectifier would add to >> the noise. Oh, to power the VFD I brought into an originally 120Vac 'only' >> cabinet 240 single phase plus the noisy 3-phase motor output. >> >> I did go back and look at my notes and 2x I did get errors in 2.6.xx that >> I ignored. I typed the errors here from a screen shot (forgive my typing >> errors): >> hm2/hm2_5i25.0: Smart Serial Error: port 0 channel 0. you may see this >> error if the FPGA card read thread is not running. This error message will >> not repeat. >> >> hm/hm2_5i25.0: Smart serial card hm2_5i25.0.7i77.0.0o error = (13) >> Communication error >> >> hm/hm2_5i25.0: Smart serial card hm2_5i25.0.7i77.0.0o error = (4) Extra >> character >> >> hm/hm2_5i25.0: Smart serial card hm2_5i25.0.7i77.0.0o error = (3) Timeout >> ----------------END ERRORS----------------------------- >> >> I only saw those errors 2x and I'm going to guess that it was after I >> upgraded the 7i77 firmware... >> I think I was lulled into thinking the noise was OK. >> >> After that, I must have fiddled w/ the power supplies and haven't seen >> those errors lately. >> >> Anyway, chasing the noise is a frustrating tail chasing exercise (for me >> it seems). I'd like to pretend it doesn't exist and stick my head in the >> sand... >> >> Mark >> > ------------------------------------------------------------------------------ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
