VFD Router Shielding Best Practice Guide?

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Scott106
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VFD Router Shielding Best Practice Guide?

Post by Scott106 »

Hi, I'm running a new router build with a 2.2KW 220V water cooled router with a VFD and Acorn Pro. I'm getting the random "327 Fault" with the VFD on and either manually jogging or running a program. Searching the forums I learned it was possibly interference from the VFD triggering the Acron to stop and after testing it with the VFD off it workd fine. So I know what the problem is.

My Question: Is there a best practices guide for cables, shielding, cable paths, optically isolated circuits, faraday cages, telekenisis, blak holes, portals or alien technology that people know of for a standard acorn / vfd router build?

Thanks in advance
tblough
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Re: VFD Router Shielding Best Practice Guide?

Post by tblough »

Please do not use black holes. People think they are great because the do absorb the unwanted EMF, but the problem is that they also absorb the step and direction signals, the 24V power, and the 120V/220V mains power. They are more trouble than they are worth.

Make sure the power cable for your spindle is shielded and grounded at both ends. Make sure the step and direction wires to your drives are shielded, twisted pairs and the shields are properly grounded at least at the source end. Power and signal wiring should be routed as far away from each other as possible and if they must cross, they should cross at 90° to each other.

Your Ethernet cable connecting the PC to Acorn should be the one supplied by Centroid. If not, it MUST be a shielded Ethernet cable with metallic RJ-45 connectors. The ethernet cable should be a single, continuous cable with no bulkhead couplings or other connection devices between the Acorn and PC.

The power supply supplied with the Acorn should be used to power only the Acorn and sensors connect to the Acorn inputs. It should not be used to power your drives or contactors. Use a separate power supply for this, but make sure the power supply commons are connected together. Any inductive device (coil, motor, fan, solenoid, etc) connected to one of the Acorn output relays must have a proper snubber connected across the coil terminals. This will not necessarily help with noise issues, but to keep from destroying the Acorn relays.
Last edited by tblough on Tue Aug 16, 2022 9:17 pm, edited 1 time in total.
Cheers,

Tom
Confidence is the feeling you have before you fully understand the situation.
I have CDO. It's like OCD, but the letters are where they should be.
Scott106
Posts: 4
Joined: Sun Jul 10, 2022 2:17 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 3484e41c09ed-050422186
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No

Re: VFD Router Shielding Best Practice Guide?

Post by Scott106 »

Excellent thanks for the reply and in plain english. I do agree about the black holes. ;)

Time to upgrade my cables!

I'm going to go through the wiring and and replace them with shielded ones. I'll reply back once i get the new ones in and grounded. Its doing all sorts of squirrley things from it causing the 327 to random emergency stops that is just like I tripped the emergency stop button so im sure it is all related to that.

thanks for taking the time!
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