On Saturday 30 May 2020 01:36:25 andrew beck wrote: > sweet as gene > > actually on this currently I have 2 big blocks for grounding. both > connected together with a decent 6 mm cable. is that enough to work > as one ground block or do I really need to get and machine/ buy > another grounding block that is all one piece > > > the latest is the E stop circuit wasn't working. So I disconnected it > and put a push botton right at the servo on input on the servo drives > and that works to trigger control power on and off to the servos. so > I will go looking through the rest of the E stop circuit. there is > something on the estop circuit that didn't like me connecting the > field io power 0v to the machine frame ground.
Thats wierd, but doesn't trigger any memories here. > regards > > Andrew > > On Sat, May 30, 2020 at 4:55 PM Gene Heskett <ghesk...@shentel.net> wrote: > > On Friday 29 May 2020 22:14:57 andrew beck wrote: > > > sweet thanks gene > > > > > > I will take your advice and connect the pc chassis to the main > > > ground. > > > > > > I think I will continue to use my grounding blocks for now though > > > as there are about 20 ground cables to connect up and that is > > > getting a bit much for one bolt I think. hopefully I don't have a > > > problem. I will let you know if I do haha > > > > Use only one block, and put them as close together as you can. > > > > > regards > > > > > > Andrew > > > > > > On Sat, May 30, 2020 at 2:00 PM Gene Heskett > > > <ghesk...@shentel.net> > > > > wrote: > > > > On Friday 29 May 2020 21:22:09 andrew beck wrote: > > > > > thanks guys > > > > > > > > > > just one question about all this gene > > > > > > > > > > why do you suggest breaking the ground off the the computer > > > > > powersupply cable and connecting a ground from the pc chassis > > > > > to the machine main ground? > > > > > > > > > > does the grounding that goes through the cable now good > > > > > enough? > > > > > > > > The computers 3rd wire should remain if its the ONLY ground > > > > connection in the whole system. But since we power gear thru EMT > > > > tubing, and that also includes a generally better ground, the > > > > power cord to the computer should have that 2nd or 3rd ground > > > > removed, and the computers ground taken back to this common bolt > > > > by a direct from its chassis ground wire, UNLESS the computer is > > > > mounted to and mechanically connected to the frame of the > > > > machine and this frame is grounded to that common bolt. > > > > > > > > Anytime you can lift just one of those wires from that bolt, and > > > > still get ground continuity because its grounded someplace else > > > > too, is bad kharma, find that "other" ground and disconnect it. > > > > Once, done well, is enough. A shielded cable where the shield > > > > is grounded at the far end can inject many volts of noise, > > > > enough to blow the interface card. Disconnect that far end. That > > > > bolt should connect to the power wirings "static" ground, and > > > > the only allowable cross connected point to the powerline > > > > neutral is in the main entrance box. You don't care if a nearby > > > > lightning strike might cause that bolt to be 200,000 volts from > > > > ground for a microsecond during that strike, but the +5 volt > > > > line will be 200,005 volts, or 5 volts from what it considers > > > > its ground might be at that exact instant. You will be damaged > > > > ONLY if some other point in the circuit breaks down and some of > > > > that lightning bolts energy actually flows thru your system to > > > > get to that better ground. Block it with air, the more the > > > > merrier. > > > > > > > > > regards > > > > > > > > > > Andrew > > > > > > > > > > On Fri, May 29, 2020 at 11:53 AM Leonardo Marsaglia > > > > > <ldmarsag...@gmail.com> > > > > > > > > > > wrote: > > > > > > > Connect all grounds to this bolt, checking that they are > > > > > > > not grounded at the far end. By doing this, you are > > > > > > > establishing a single point ground that is the zero volt > > > > > > > reference for the whole system. Connect this bolt to the > > > > > > > building static ground, the bare wire in most power > > > > > > > cabling. > > > > > > > > > > > > > > Connect the machines frame to this bolt. > > > > > > > > > > > > > > Connect the - rails of all supplies to this bolt. > > > > > > > > > > > > > > Connect the - terminals of all cards to this bolt. > > > > > > > > > > > > > > Break the 3rd pin off the computers supply cable and > > > > > > > connect the computers chassis to this bolt. Power the > > > > > > > computer not from the wall, but from the same power > > > > > > > feeding this box. > > > > > > > > > > > > > > Connect the shielding of all shielded cabling to this > > > > > > > bolt. Do not connect the far end of this shielding to > > > > > > > anything that is otherwise grounded. > > > > > > > > > > > > > > By making sure these grounds are not connected anyplace > > > > > > > else you are breaking any ground loops which can and will > > > > > > > act as antennas to insert noise into your control signals. > > > > > > > > > > > > > > By having this single point ground, a nearby lightning > > > > > > > strike can inject a 100k volt pulse into the system ground > > > > > > > as what would be called a "ground bounce", but the system > > > > > > > will not see it as noise nor be damaged, because > > > > > > > everything is bouncing in unison. > > > > > > > > > > > > > > Regardless of what that bolt does during the strike, the 5 > > > > > > > volt supply remains at 5 volts to this bolt, and the 24 > > > > > > > volt supply remains at 24 volts to this bolt. > > > > > > > > > > > > > > And when the storm is done, your chances of having > > > > > > > anything damaged is reduced to the vanishing point. > > > > > > > > > > > > Thanks for this Gene. It's more than useful to remember how > > > > > > to properly ground logic circuits to avoid external noise > > > > > > and dangerous voltage spikes. > > > > > > > > > > > > El jue., 28 may. 2020 a las 20:35, Gene Heskett > > > > > > (<ghesk...@shentel.net>) > > > > > > > > > > > > escribió: > > > > > > > On Thursday 28 May 2020 18:36:10 andrew beck wrote: > > > > > > > > hey gene > > > > > > > > > > > > > > > > sorry for the slow reply > > > > > > > > > > > > > > > > just getting to this grounding thing now. > > > > > > > > > > > > > > > > currently I have single large copper block with a lot of > > > > > > > > holes in it for terminals, this is connected to the > > > > > > > > earth(ground) wire that goes back to the whole shed main > > > > > > > > ground wire rod in the dirt > > > > > > > > > > > > > > > > all my servo drives and vfd main grounds go back to this > > > > > > > > point as do all motor grounds etc. this is how > > > > > > > > heidenhain set up the machine originally and they have a > > > > > > > > whole grounding schematic showing how it all works. I > > > > > > > > have basically copied that. > > > > > > > > > > > > > > > > I have 2 meanwell 24v powersupplies that have the ground > > > > > > > > wire on the input side also connected to ground. the > > > > > > > > output side (phase and neutral) are floating relative to > > > > > > > > ground and not connected to ground at all I think. as > > > > > > > > the meanwell switching powersupply output should be > > > > > > > > isolated from the input. I think this is correct > > > > > > > > > > > > > > > > the computer cord ground wire is currently connected to > > > > > > > > this same large copper block. > > > > > > > > > > > > > > The sheer bulk of that copper bother me a bit because it > > > > > > > can function as an antenna. A single bolt, tightened well > > > > > > > into the chassis with all the connections stacked up on > > > > > > > this bolt will be quieter. > > > > > > > > > > > > > > > my computer via the 5i25 currently supplies 5v logic > > > > > > > > power to the 7i76 > > > > > > > > > > > > > > Thats fine, but if using a std bob on the other 5i25 port, > > > > > > > do NOT enable the jumper for that port as the bobs std > > > > > > > grounding will short circuit that, you must supply a > > > > > > > separated 5 volts to that bob, or plug in a usb cable to > > > > > > > steal it from the pc's usb circuitry, > > > > > > > > > > > > > > > and one of the 24v meanwell powersupplys supplies the > > > > > > > > 24v field io for the 7i76 > > > > > > > > > > > > > > I have all supplies - outputs tied to ground. It might > > > > > > > work 99% of the time without it, till the first nearby > > > > > > > lightning strike... With all that grounded, it will > > > > > > > probably keep right on working after the strike. > > > > > > > > > > > > > > > my encoder problems started when I connected up the > > > > > > > > servo drive simulated encoder output to the 7i76 encoder > > > > > > > > counter. I haven't connected the 5v and 24 v grounds > > > > > > > > together. they did work for awhile but don't now > > > > > > > > > > > > > > Tie the -'s to the ground bolt. Then do a full powerdown > > > > > > > on the whole thing, with about a 10 count in the dark, > > > > > > > then boot everything back up and test it. And report what > > > > > > > you get now... > > > > > > > > > > > > > > > I have a 7i89 and 7i84 coming soon and will need a > > > > > > > > external 5v powersupply anyway i think so will change > > > > > > > > when they arrive here from america. > > > > > > > > > > > > > > > > anyway I read your reply and got a bit confused could > > > > > > > > you read my email here and let me know what I need to > > > > > > > > change and why I should do it this way just so I > > > > > > > > understand. > > > > > > > > > > > > > > Basicly, your lack of a common ground has possibly allowed > > > > > > > voltages well above the breakdown voltages of the chips on > > > > > > > these cards, between the - connections and a real ground. > > > > > > > They all have what can look like an SCR as an isolation > > > > > > > tub under each transistor its built from, and these SCR's > > > > > > > can upset the whole thing if they get turned on. Thats > > > > > > > why the count to 10 or more powerdown is done, giving > > > > > > > these SCR's time enough at a low enough voltage to turn > > > > > > > them off, at which point the circuit looks more normal and > > > > > > > may even work. If not, then something has been damaged on > > > > > > > the card and it should be replaced or tested and repaired > > > > > > > as needed by Peter. His turnaround time from CA to WV here > > > > > > > in the states has been very good. Its several thousand > > > > > > > miles. But if I recall correctly, you are not exactly > > > > > > > local. > > > > > > > > > > > > > > > regards > > > > > > > > > > > > > > > > Andrew > > > > > > > > > > > > > > > > On Thu, May 21, 2020 at 9:31 PM Gene Heskett > > > > > > > > <ghesk...@shentel.net> > > > > > > > > > > > > > > wrote: > > > > > > > > > On Thursday 21 May 2020 01:57:06 andrew beck wrote: > > > > > > > > > > hey peter > > > > > > > > > > > > > > > > > > > > I had a look and the unless there is a shorted out > > > > > > > > > > pin in the servo drive connector itself I think the > > > > > > > > > > wiring is all good. > > > > > > > > > > > > > > > > > > > > and I highly doubt the servo drive has problems all > > > > > > > > > > I did was connect the 24v back into the servo on pin > > > > > > > > > > which is how it has been running for the last ages. > > > > > > > > > > > > > > > > > > > > anyway how do you recommend commoning the grounds? > > > > > > > > > > > > > > > > > > > > it is as simple as connecting the field power 0v > > > > > > > > > > ground with a wire to the logic power 0v ground? > > > > > > > > > > > > > > > > > > Yes, but how you do it can be very important. > > > > > > > > > > > > > > > > > > In your control box, install a longer bolt, #6 or > > > > > > > > > #8-32 to the chassis. 4mm if metric. > > > > > > > > > > > > > > > > > > Connect all grounds to this bolt, checking that they > > > > > > > > > are not grounded at the far end. By doing this, you > > > > > > > > > are establishing a single point ground that is the > > > > > > > > > zero volt reference for the whole system. Connect this > > > > > > > > > bolt to the building static ground, the bare wire in > > > > > > > > > most power cabling. > > > > > > > > > > > > > > > > > > Connect the machines frame to this bolt. > > > > > > > > > > > > > > > > > > Connect the - rails of all supplies to this bolt. > > > > > > > > > > > > > > > > > > Connect the - terminals of all cards to this bolt. > > > > > > > > > > > > > > > > > > Break the 3rd pin off the computers supply cable and > > > > > > > > > connect the computers chassis to this bolt. Power the > > > > > > > > > computer not from the wall, but from the same power > > > > > > > > > feeding this box. > > > > > > > > > > > > > > > > > > Connect the shielding of all shielded cabling to this > > > > > > > > > bolt. Do not connect the far end of this shielding to > > > > > > > > > anything that is otherwise grounded. > > > > > > > > > > > > > > > > > > By making sure these grounds are not connected > > > > > > > > > anyplace else you are breaking any ground loops which > > > > > > > > > can and will act as antennas to insert noise into your > > > > > > > > > control signals. > > > > > > > > > > > > > > > > > > By having this single point ground, a nearby lightning > > > > > > > > > strike can inject a 100k volt pulse into the system > > > > > > > > > ground as what would be called a "ground bounce", but > > > > > > > > > the system will not see it as noise nor be damaged, > > > > > > > > > because everything is bouncing in unison. > > > > > > > > > > > > > > > > > > Regardless of what that bolt does during the strike, > > > > > > > > > the 5 volt supply remains at 5 volts to this bolt, and > > > > > > > > > the 24 volt supply remains at 24 volts to this bolt. > > > > > > > > > > > > > > > > > > And when the storm is done, your chances of having > > > > > > > > > anything damaged is reduced to the vanishing point. > > > > > > > > > > > > > > > > > > Stay well Andrew. > > > > > > > > > > > > > > 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 > > > > > > > > > > > > _______________________________________________ > > > > > > 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 > > > > > > > > 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 > > > > > > _______________________________________________ > > > Emc-users mailing list > > > Emc-users@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > 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 > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users 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
