Wiring VFD to E-Stop

(Ummm, not sure, but I’ll try...) #1

My current 120v E-stop is simply connected to a 4 outlet power strip that has my router, light and SO3 plugged into it. Hit the E-stop, everything off.

What’s the best way to incorporate this sort of manual disconnect with a 220v VFD?


(Julien Heyman) #2

I naively did it exactly like you did, my 220V VFD is plugged in a 4 outlet power strip that my E-stop kills.
But I may not be aware of subtleties of 220V vs 110V wiring in the US though…


(Ummm, not sure, but I’ll try...) #3

I doubt naive, but all your circuits are 220. For us, here in the US, we need to wire two flavors (110 and 220) to an E-Stop. I’ve been Googling, just getting confused


(Julien Heyman) #4

Got it. Double pole E-stop maybe ?


(Luke (Carbide 3D)) #5

Depends on what your estop does. If it’s a power kill no. A spindle can decelerate way faster than then it can just slow down.


(Luc) #6

Here is one from Grizzly that you could connect to your 220 spindle.


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(Daniel Story) #7

I don’t know the right term/name for these switches, but they are modular, the top switch button controls the switch state (push button, on/off, rotary, etc) then the switch contacts control open/closed state and are stackable. I use several of them.

I stack two of the switch contact blocks, giving me two of each NO and NC circuits; 4 isolated circuits total.


(Ummm, not sure, but I’ll try...) #8

So you’re recommending some sort of software code to stop the spindle?

So I’d initiate a spindle stop through a terminal on the VFD? How would that be triggered? I’d still want to cut power to the spindle physically.

I’ll also check out the switches referenced by @DanStory.


(Ummm, not sure, but I’ll try...) #9

So, I wire 220 to one and 110 to the second? Seems simple enough. Plus, I think that’s the switch I have now.

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(Neil Ferreri) #10

Wouldn’t cutting power to the controller stop the pwm signal and stop the spindle? (I don’t have a vfd spindle)


(Ummm, not sure, but I’ll try...) #11

I think what Luke is saying is that the spindle does not stop immediately upon loss of power. It takes a while to spin down thus an opportunity for further mayhem in the event of a problem. Whereas, I’m guessing, a software stop would “put the brakes on”.

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(Luc) #12

My only concern with that is the loss of communication to the controller that happens from time to time due to emi or static.


(Neil Ferreri) #13

Isn’t that just a pwm of zero? I thought maintaining power, but setting speed to zero would be how you’d brake. Again, no experience with a vfd.


(Daniel Story) #14

Yep, I actually bought a mix match of switches as I couldn’t find ones with the exact NO/NC combinations and reconfigured them to my liking and use cases.

I have a main power e-stop that cuts all power, and a second e-stop that uses the software stop/hold mechanism. Depending on the situation and level of emergency. Also, I have a router, so no spindle braking.

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(Ummm, not sure, but I’ll try...) #15

So, my question now is: how do I get my e-stop to send this pwm-to-zero signal while all power is being cut? Asked by a woodworker and occasional electronics tinkerer.


(Neil Ferreri) #16

I’d just try cutting power to the controller. The pwm signal has to be zero when there’s no power.
(Again, no vfd spindle experience)


(Luke (Carbide 3D)) #17

Correct. On one of my machines if I kill the power - to everything the spindle will just keep going. Might be a enough voltage is stored in the power supply. It can keep spinning for 10-20 seconds. If I put in the M5 command spindle setup it killed in 1-2 seconds.

I don’t know if just cutting PWM will stop the spindle or not, on mine it doesn’t. If you lad a latching switch between pwm and the spindle it might work. When latched the signal passes, when not no power would go through.

Depending on the CM board you have a couple of stop options. One is pause - this will pause movement but spindle (M5 command not set) stays on. There is another which turns off the spindle and movement.

I don’t know which one will be on your board and can’t recall which boards have which.


(Ummm, not sure, but I’ll try...) #18

Yeah, I saw that when testing. Must be some big caps in theVFD acting like batteries.
Controller is an XPro V4.


(Neil Ferreri) #19

Was that an M5 for a spindle stop?
You can enable parking as a compile time option.

I would still think that a power off on the grbl controller would have the same effect. Wonder why it doesn’t.

On M5, it’s my understanding that the pwm signal is just turned off.

This is making me more jealous of you guys and your big spindles.


(Ummm, not sure, but I’ll try...) #20

Please give in to temptation and get one so you can learn all about it and put me out of my misery!