Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: kolias on April 22, 2016, 04:37:56 PM

Title: Shielded Cable to Earth Ground?
Post by: kolias on April 22, 2016, 04:37:56 PM
The cable for each of my four 381oz.in stepper motors is 18AWG shielded. At the opposite end of each motor I connect the 4 shields together and go with 1 wire to the earth ground (that’s the earth ground from the 120VAC).

For the 46VDC /7.3A power to each motor driver I use 20AWG shielded cable. I did not daisy chain the drivers but rather I took separate cables from the PSU to each driver. Should I connect the shield from these cables to the earth ground or it’s not required?
Title: Re: Shielded Cable to Earth Ground?
Post by: Davek0974 on April 23, 2016, 03:29:08 AM
Generally you want to connect the shields to the star ground point in the control cabinet - this is the single grounding point for all ground connections.

Only connect the shields at the source end of the cable - the driver end, insulate the the motor end or you risk forming ground loops - circular paths for earth current that can cause a lot of problems.

You were right to not daisy chain the supplies.