forum.cncdrive.com

I bought and installed a new 1.5hp water-cooled spindle with an inverter to run it. Inverter is https://www.valinonline.com/products/esv112n02yxb . Now whenever I switch the spindle on, it triggers my limit switches (in Mach3) and I can only reset it when the spindle is not running. Would adding a line reactor to the inverter help? Spindle and limit switch wiring is all shielded and properly grounded.

I'm virtually at a standstill. Any help?

Your VFD is probably a cheap chinese one with zero line filter (noise filter) on the input lines is the problem.
What happens is that the motor noise gets back to your mains lines triggering the limit inputs in your system.

You should try to install a proper line filter into the VFD mains inputs.
Also make sure to form a short as possible wires star shape grounding for the components in your system (VFD, power supply for your controller, computer etc.)

I see now that you have a Lenze VFD which is German not chinese, LOL. The link did not open for me previously, only now.
Anyways, the issue is noise for sure, so what I wrote previously is still true.

What type of limit switches do you have?

Proximity?

Check your earth (ground) arrangement / wiring

Thank you for the suggestions.

These VFDs are manufactured in the US. I'm sure some components are coming from China. I thought of re-configuring the limit switches as normally closed.

24V limit switches are much more immune to noise than a 5V system, if that's what you are using.

Based on suggestions here and on other forums, here's what I've done on my mill to eliminate noise-related bugs. So far I've not had any problems.

RFI filter on mains input
Line reactors on input/output to VFD
Ferrite rings on VFD output cables
VFD cables run through metallic conduit to motor
VFD cables twisted in conduit (ground not twisted with power conductors)
VFD cables/conduit not near anything else except in the energy chain to mill head - and the conduit is separated by 3" or so when it's parallel to the other cables.

Signals, including limit switches, are 24vdc.
Limit switches & spindle index proxy run as NC
Motor encoder has complimentary signals in a double-shielded cable well away from VFD conduit. Enters the enclosure at a different point than the VFD cables.

Star ground for all components. Paint scraped at all ground points on backplane, motor, machine cabinet, etc.

I'm sure there are other techniques for managing noise, but that above didn't really cost much.