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Author Topic: * * Need Help with possible ground issue and false E - STOPS* *  (Read 1639 times)

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I am in need of some ideas on a possible cure for a problem i am having with my 3 axis Shizuoka mill conversion. I will try to list the hardware i am using, but if You need more info please let me know. i ordered almost everything from cnc4pc.

Shizuoka AN-S
Mach 3
Warp 9 Ethernet smooth stepper
cnc4pc c-32 break out board REV 5.4
two c-54 quad 25 amp relay boards
Imach P4-5 MPG
Teco tsta servo drivers
Teco servos, two 1000 watt 2000 rpm and one 750 watt 3000 rpm
Teco westinghouse 7300N3   205-N1 VFD

1. When i connect the 24 volt out pin on the VFD to the common pins of the forward and reverse relays of the C-32 board, both forward and reverse led's both glow dimly.
2. If i run the spindle speed up to 5000 rpm and then issue a M5 command, the saftey charge pump, estop, and VFD alarm led's glow dimly. As the spindle is coasting to a stop, just as the spindle almost stops, those led's get brighter, flicker a bit and i get a EXTERNAL E-STOP REQUESTED. when it does this my contacter that enables my servo drives shuts off for a second then comes back on. The saftey charge pump is not enabled in mach or on the c-32 bob with the jumpers. I spoke with brian from teco westinghouse tech support and he suggested a regeneration resister of 50 Ohms and 300 watts for the VFD. I have tried running the debounce settings in mach and in the ESS up to unreasonable numbers to see if it was noise. I Installed a power filter/ conditioner thinking the vfd was giving my electronics "dirty power". I have wrapped all wires with copper tape and grounded them to the enclosure box. The vfd is mounted in a seperate box behind the main enclosure. I have also tried to make sure all high voltage wires (particular attention the the VFD) and low voltage wires are separated. I tried to jumper the 24 volt pin to the S1Forward of the VFD, bypassing the bob and the led's still glow dimly. When i do this, the only wires that are connected to the vfd  are the analog 10v and ground for the speed control. I am sorry if i am rambling and giving you useless information, i just dont know what info you need to diagnose something like this. I am finding out that i am not as good with electronics as i once thought. My first thought was improper grounding, but now i am not sure. You might ask why not just ask arturo from cnc4pc. He does not answer phone calls or emails, SORRY arturo, but you know its true. Any help would very appreciated, even just pointing me in a direction. Please let me know what info you need. Thank you in advance.

Offline Chaoticone

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Re: * * Need Help with possible ground issue and false E - STOPS* *
« Reply #1 on: May 22, 2014, 05:17:47 AM »
Hello Austin, have you read this topic? http://www.machsupport.com/forum/index.php/topic,25616.0.html  If not, hopefully it will help. Noise can be a real pain to deal with. It sounds like you have a ground loop or misplaced wire to me. You may need to float some grounds. Eliminate everything you can and get one thing working well and tested then add another. Get your motion working nice then add the home/limits and retest. Then add the spindle control and retest etc. You have to eat an elephant one bite at the time. If you do not have electrical prints you are at a severe disadvantage IMO.

. I have wrapped all wires with copper tape and grounded them to the enclosure box
This is not clear to me but if they are not insulated on top of the copper tape you now have antennas running all around (the opposite of what you want). When using shielded cable I use heat shrink on the ends for that extra little bit of insurance if that tells you anything.

;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!
Re: * * Need Help with possible ground issue and false E - STOPS* *
« Reply #2 on: May 22, 2014, 10:01:47 AM »
Thanks for your help Brett. i will look into my improvised shielding method with the copper tape. I forgot to mention That I installed ferrite cores on my 5, 12 and 24 volt power supply wires. ( from the power supply to the boards) that might not be the correct way or even necessary. That did not seem to make any difference. I printed off the first article to read when I get a spare second. I will try to disable everything until i have basic motion then work up from there. If anyone has any more helpful ideas please let me know. This is my first retro and has been a lot of fun until now. Thanks


Offline Fastest1

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Re: * * Need Help with possible ground issue and false E - STOPS* *
« Reply #3 on: May 26, 2014, 03:38:06 PM »
It is a common issue and frustrates many of us. It will be fun again, dont worry.

Take some pictures and post them, dont be embarassed about the rats nest of wiring. Something might be blatantly obvious to an experienced eye.
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)