Electrical Safety and Machine Wiring

[ma...@makr.zone]

Hi everybody

I've added a new topic to my build documentation that would like to discuss here and prepare for the next post about grounding, i.e. the application of the safety topic in combination with other grounding issues such as for ESD and EMI, ground bouncing etc.

I know the issue is difficult because of liability especially it seems (as a cliché) under US law.

Still, I think we must discuss it more.

All insights and feedback very welcome, I intend to integrate it into the post:

https://makr.zone/electrical-safety-issues/230/

Thanks a lot,

Mark

P.S. I might add that I am not very interested in the cowboy attitude. If safety issues bore you, just tune this out please. The ever present knitting needle + spittle voltage test does not impress me. Thanks.

[ma...@makr.zone]

Hi

I added another post detailing the grounding of the machine. This is work in progress so I'll gladly include hints and corrections.

https://makr.zone/grounding-the-machine/283/

How did you do it? All input welcome!!

_Mark

[ma...@makr.zone]

Nobody?

https://makr.zone/grounding-the-machine/283/ https://makr.zone/wp-content/uploads/2018/07/Grounding_the_Machine_4-1.png

 

[Paul Kelly]

Earths as shown are better than no earths.

The best way is to wire from the earth on the power socket to a chassis bolt and then from that bolt, and only that bolt, run earth connections to everything, Including the screens on the stepper drive cables.

This is called a star ground and is a good starting point.

 

Frankly, it’s less of an issue with little stepper systems. We paid careful attention to it on our machine with its 80V, 350W DC servo drives.

When you are trying to do something like this:

https://www.youtube.com/watch?v=bRcdnlEXedg&ab_channel=gyrodoug1

It’s critical.

PK

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[Mike Menci]

Hello, 

I noticed with TinyG and LithPlacer that Ground is VERY important for Vision to work properly. When moving my hand to camera suddenly the Vision was working much better - this is when I did all the ground wiring as many I could.  Surly, from main to Switching power supply and body of PnP the ground should be solid and fuse installed.

Cheers! 

Mike

[ma...@makr.zone]

The best way is to wire from the earth on the power socket to a chassis bolt and then from that bolt, and only that bolt, run earth connections to everything, Including the screens on the stepper drive cables.

This is called a star ground and is a good starting point.

Yes, this is exactly one of the question marks.

What I was trying to do was a "star-of-stars" grounding configuration, actually. The reason is what I tried to describe in point 12 of my post (I changed it to try and explain more clearly now).

_Mark