[mactec54]

Update and current status...

There were two ways I was able to monitor the problem: False triggers of buttons from the operator panel and my Scope. Being that the false triggers appeared to come from the buttons and switches attached to the I-PAC (keyboard emulator), I figured I would connect my scope to that device which is located inside the operator panel.

Here is a trace that was captured with the spindle running. The spikes were about 3.8 volts as measure on one of the inputs to the I-PAC. With about 30 inputs on the I-PAC, I was getting some really strange things happening.
Attachment 420874

Trying to determine if the noise is conducted or radiated, I removed the cable from between the electrical cabinet and the operator panel. The voltage spike is reduced to about 2 volts. Being that, aside from the AC power, there was no mechanical connection and the voltage spikes are still present, I could only assume I had both, conductive and radiated noise. At this level, there were no problems of false triggers and the machine ran fine. Here is the trace showing that.
Attachment 420882

From the advice of Mactec, I purchased and installed a line filter. At first I didn't understand how that would even help this problem, but then I realized this device is very similar to a "Reactor" which is used on industrial CNC machines for preventing noise issues. This is the link to the line filter https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1. Once installed, there was an immediate improvement in the noise levels...
Attachment 420876


However, the presumably radiated noise was still there. As this did not affect operation of the machine, I wasn't too worried about it.

I continued to tidy up the wires and prepare to close up the electrical cabinet and the operator panel. I performed one last check with the scope. During my tidy up process, more improvement occurred, unfortunately, I have no idea what changed to remove the radiated noise. I know I pushed all the wires back into the plastic conduit, I recall reattaching the 220VAC ground wire be (from source) and at the line filter and I am sure I did a few more things but can't recall all the details. Here is the trace before I closed everything up..
Attachment 420884

Knowing that I had a working system at one point, then this noise issue came up, I am not 100% certain the problem isn't fixed. The problem very well could come back again but for now I am a happy camper.

Here is a photo inside the electrical cabinet just before closing. The Line filter was attached to the 35 Volt power supply, probably not the best thing to do, but currently there are no ill effects and it was a handy place to mount it. As mentioned in an earlier post, I was worried about accidental shocks being that the posts on this thing are fully exposed, I designed and 3D printed a red cover for it so that it would be a bit more safe then being fully exposed.
Attachment 420886

What a nightmare this problem was and to deal with. I am hoping that it is over and I learned a few things along the way.

Thank you to all of you guys for your help and guidance!

Chris D

Most likely had a lot to do with when you reconnected the Ground, glad you where able to see what the Power Filter can do, A power filter is a cheap replacement for a reactor, and can almost do the same job, if everyone that installs a VFD did this it would solve a lot of there problems, Grounding of course is a number 1 problem most of the time, switch mode power supplies can be another source of noise which should have a Power filter also, or any DC Power supply in general, the coils of wire will create a magnetic field around them also, but may not cause to much of a problem as they are away from the Breakout Board area

Cover looks good and Ideal 3D printers can save the day but if someone does not have one any type of cover material will do the job if a cover is needed for safety

If your switches are noisy then you may need a cap / snubber across them

[wmgeorge]

Nice job on the Insulating common sense cover for the filter. Glad we could help, and your scope like mine helped finalize the job insuring there were no more issues

[ericks]

Chris i am glad you got it sorted....hope it goes well from here

[Chris D]

A bit more information that may help others...

There was a bit of discussion as to how to ground shields and star grounding etc. I do not wish to continue that discussion or further debate on either side of right or wrong, however, I did take a few photos of how I have seen this done on high-end CNC equipment. These photos are from a Japanese built 5 axes CNC machine.



STAR GROUNDING -- often this is explained as a bolt or stud on the side of an electrical cabinet and ALL wires somehow magically stacked up on that single lug. This is the same principle but far more practical and certainly a lot more practical to implement.
Attachment 421114

As you will quickly recognize in this photo, this machine uses a FANUC control. These cables are servo and encoder cables. Notice the "grounding bar" for the shielding and how the clamps press against the shield. Also of note is how the insulation is cut away in the "middle" of the cable for the grounding and yet allows for the shield to continue to the connector (end) of the cable. I thought that this was very interesting. This style of shield grounding has been used in many different industrial CNC machines over the years that I have been working on.
Attachment 421116
Attachment 421118

Just thought that these examples of star grounding and shield grounding could be useful to others.

Chris D.

[mactec54]

A bit more information that may help others...

There was a bit of discussion as to how to ground shields and star grounding etc. I do not wish to continue that discussion or further debate on either side of right or wrong, however, I did take a few photos of how I have seen this done on high-end CNC equipment. These photos are from a Japanese built 5 axes CNC machine.



STAR GROUNDING -- often this is explained as a bolt or stud on the side of an electrical cabinet and ALL wires somehow magically stacked up on that single lug. This is the same principle but far more practical and certainly a lot more practical to implement.
Attachment 421114

As you will quickly recognize in this photo, this machine uses a FANUC control. These cables are servo and encoder cables. Notice the "grounding bar" for the shielding and how the clamps press against the shield. Also of note is how the insulation is cut away in the "middle" of the cable for the grounding and yet allows for the shield to continue to the connector (end) of the cable. I thought that this was very interesting. This style of shield grounding has been used in many different industrial CNC machines over the years that I have been working on.
Attachment 421116
Attachment 421118

Just thought that these examples of star grounding and shield grounding could be useful to others.

Chris D.

That's exactly the same way as I tell everyone to do it, and it is the correct way it should be done, they are using a Ground Bus which is there Star Ground Point, Shield clamps come in different forms this is just one way with this type of clamp for Shields