VFD safety off question

Okay so I have a Journeyman X50 that I just installed an 80mm air cooled 220v spindle on. I’m using a Huanyang VFD. Everything is operational. I’m using a breakout board to control the VFD. So here’s what I’m wondering,

If power is lost to the controller or if the controller failed for some reason the VFD will keep running the spindle as it hasn’t received a stop command. How do I make it so that power is also cut to the VFD at the time of power loss to/or failure of the controller. I was thinking that a magnetic switch controlled via the breakout board or something would be the way to go, however the VFD manual says not to use a magnetic contactor on the power feed. Is there a way to setup an estop feature to active if the controller lost power?

I apologize if this has been covered. I saw similar discussions but nothing with a clear resolution.


I have a buildbotics controller and RJ45 setup to the VFD.

It is possible to set the VFD to poll the controller (P36 set to Index 3 in my case). If a signal is not received within 1 second the VFD goes to STOP. You need to make sure the controller is always sending comms to the VFD. I do this by configuring the controller to ask for a VFD read status.

If the controller stops working, it stops sending read status requests to VFD and the VFD shutdowns within 1 second.

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Hey Dustin,

the VFD and the CNC controller have to be wired in a way that they are part of the emergency stop circuit. The VFD should signal an alarm to the CNC controller if there is a problem with the spindle (not) running, which then will stop the running g-code program, but also should the VFD stop the spindle when there is an alarm of any kind, be it from CNC controller, or from something else, e.g. if someone opens the door of the CNC machine’s enclosure etc. For this, there exist dedicated Safety relays and sophisticated emergency circuits.

I tried to make my best to answer this question in this forum in the past:

E.g. you could have found this posting.

How do I set the controller to always send comms?

Optidrive E3 VFD - #3 by AndyP?

Try this post in which i describe my ssettings. I expect your VFD settings will differ