View Full Version : VFD in main electronics cabinet/general layout?

09-04-2013, 11:21 PM
Will there be any issue with mounting the VFD for the spindle motor inside the main electronics cabinet?
I know VFDs are a major source of noise, but will it be any worse than a trio of brushless servo drives?

I'm planning on having everything (mobo, harddisk, Kflop/Kanalog, relays, contactors etc) in the one cabinet. My plan is to have all the high voltage stuff (contactors/VFD/Drives) at the bottom, Kflop kind of central with output relays of to one/both sides, then motherboard and associated bits at the top.
All inputs/outputs are going to be 24v or differential, with sheilding/grounding where appropriate.

Anybody see any issues with that plan?

10-04-2013, 07:27 AM
should be ok. pay particular attention to earth star point to avoid ground loops and cable routing to keep power and control apart as far as possible. . also make sure you have RFI filter at AC input to vfd

10-04-2013, 07:17 PM
Thanks for that Irving.

I'm already planning on keeping the power/control cables seperate in the control box as much as possible, but there are going to be various points in the machine where everything is going to be bundled together to get around the structure. That's why I'm opting to use 24V for any switching input, and differential for anything that can't be 24V, so noise shouldn't be an issue.

11-04-2013, 12:46 AM
just got my VFD up and running and whilst going through the install section noticed that it can be installed in an enclosure but needed ventilation and a cooling fan. might be the same for yours! could be a bit toasty with the servo drives as well.

11-04-2013, 06:00 PM
Cooling is always something to consider, however this cabinet is a bit larger than your typical homebrew CNC enclosure (I think I measured it at 1.2 x 0.8 x 0.3m), has an integral air to air heat exchanger, and previously housed a Heindenhain controller complete with all drives/transformers/contactors.