On/Off switch for VFD

[Patrick Kane]

I searched and read a few different threads on this topic, but they were old and the links to amazon or other retailers were broken. I have a saw im converting via a VFD; however, i dont want to control the saw via the teeny tiny VFD controls. It isnt often, but i have had to shut down a saw a time or two in sketchy situations. The other threads discussed not wanting a magnetic paddle switch, and that some switches would ruin my ability for soft start and braking. I would prefer an on/off switch that still maintained the VFD's abilities to soft start and brake the saw. Has anyone done this and if so, what is the specific product you used?

[Bruce Whitaker]

Patrick,

try the Factorymation site. https://www.factorymation.com/?utm_s...SAAEgKt5PD_BwE

I have three VFD's from them and I think you will find what you are looking for there. Their tech support is great and can recommend what you need.

[Jon Nuckles]

If the above suggestion does not yield the answers you need, try OWWM.org. You'll have to register (it's free) to look at the "everything electrical" section. There you will find all the answers to any VFD question you might have. Lots of other good stuff on the site as well.

[Patrick Kane]

Didnt even think to check OWWM. I am a member already, but modern technology and OWWM just didnt click.

[John K Jordan]

My lathe has a separate remote "emergency" switch to turn the rotation off in a hurry - it respects the deceleration/acceleration parameters. It is wired to the same low-voltage control terminals as a on/off switch on the front of the lathe. It does NOT power down the VFD.

I have a two-pole 220v power switch in the line to kill the power to the VFD. If the VFD is powered up again by the 220v switch, then it either does nothing (until the on/off control switches are closed) or soft starts. Works well.

JKJ

[Rod Sheridan]

Mine uses a start and stop pushbutton to control the VFD............Rod.

[Jared Sankovich]

It's simple to do with the control terminals. Your vfd should support 3 wire control. Run the common terminal through a NC switch for the stop function and use any momentary for thr start.
You can ignore the reverse terminal

This is the fuji setup
Screenshot_20181203-164439.jpg

[Bill Dufour]

If you like the existing switch it should be easy to rewire it to control the vfd.

[Geoff Crimmins]

Any on/off switch should work fine. You just run a wire from the vfd to the switch and then back to the vfd. The vfd manual should tell you which terminals to wire the switch to. I expect Grizzly has switches that will work fine that have have big push buttons. I think the concern about acceleration and deceleration settings comes into play if you use the momentary push buttons that were used with the saw's magnetic starter.

I think something like this would work. The power rating for the switch doesn't matter because it's only switching the low-voltage control circuit from the VFD. The power cord and the motor are both wired directly to the vfd and do not pass through the switch.

http://www.grizzly.com/products/Wood...e-Switch/D4160

[Tom Trees]

If you don't mind making a housing for the switch then a pair of 2 quid push buttons will be suitable
Thats a green NO switch (NO means normally open), and a red NC (normally closed)
You can buy an encased mushroom style for a quid more, you can also have as many NC stop switches as you like.
If you dont want to make a box for the switch you can buy a button station but their probably at least 15 quid, if not more.
I like having a big paddle myself for the tablesaw

You might also possibly need a relay depending on the brand of VFD you chose, most I've seen have a built in relay so no need for that 5 quid component.
Paddle switch 1.jpgPaddle switch 2.jpgSAM_0941.jpg
Tom

[Jared Sankovich]

Any on/off switch should work fine. You just run a wire from the vfd to the switch and then back to the vfd. The vfd manual should tell you which terminals to wire the switch to. I expect Grizzly has switches that will work fine that have have big push buttons. I think the concern about acceleration and deceleration settings comes into play if you use the momentary push buttons that were used with the saw's magnetic starter.

I think something like this would work. The power rating for the switch doesn't matter because it's only switching the low-voltage control circuit from the VFD. The power cord and the motor are both wired directly to the vfd and do not pass through the switch.

http://www.grizzly.com/products/Wood...e-Switch/D4160

A single on off switch to the vfd does not offer the safety features of the original mag switch (power loss restarts)

[Matt Mattingley]

A single on off switch to the vfd does not offer the safety features of the original mag switch (power loss restarts)

Sure it does. My lathe has a forward reversing drum switch. If the VFD loses power and it comes back on with the drum switch set to forward or reverse a fault is thrown. I have to manually reset the fault on the keypad. If I do this and I disregard the fact the fault was there. Sure it starts back up. But I would be an idiot.

But my set up is,

-Power in to a three wire control contactor that has a push/pull E stop button and a start button that upload power to the VFD.
-Then the VFD is controlled using the drum switch for forward and reverse. Two wire control latching circuit.
-Then I set one of the parameters “to power on terminal protection”. This means if the terminals are not in their neutral state a fault gets thrown on the display. It only takes hitting the clear button once to say everything is clear and I’ve analyzed why there is a fault.