Both dust collection auto on/off (wood) and air blast auto on/off (alum/plastic)

[AndyP (Badger)]

@Aiph5u thank you for a well written article.

[MVall (Martin)]

Thanks @Aiph5u. When I started down the road of automating the dust collection from the VFD, I suppose I didn’t realize what I was getting in to as a non-electronics guy. Not exactly plug and play. I’m sure matching up relays and wiring in a diode is very simple for those who know, but a bit intimidating when you don’t, especially when attached to a fairly expensive VFD. But I’ve learned a good amount thanks to your generous and clear explanations. Take care

[Aiph5u (Aiph5u (not affiliated with Onefinity))]

Hey Martin,

these two questions I forgot to answer:

@MVall

I also considered a simple SSR like this one which lists minimum control current of 5mA and max control current of 25mA. Also within the specs. Would I still need an external power supply and a flyback diode with a SSR?

Now the link works in my country too (strip everything except /dp/ASIN from the URL):

https://www.amazon.com/dp/B08GP8L31L/

no, a solid-state relay needs no flyback diode, because it has no coil to control it but a semiconductor (usually a thyristor). But this changes nothing on that on an open-collector output, you need a voltage to trigger the control input.

@MVall

At this point I’m also happy to go with the IoT relay that many use with the OF controller, but I don’t know how that interacts with an open collector output on a VFD.

This one? External IoT relay (FAQ)

The little green input on the side is like the control coil.

[MVall (Martin)]

Thanks for coming back to this, @Aiph5u . This has given me 3 good options that I can see:

1. electromagnetic relay with 24v power supply and flyback diode. Thanks for the suggestion on the diode. If I can do this, it sounds like a nice option.
2. possibly SSR with 24v power supply
3. according to this U.S. manufacturer of relay modules, this 20A dry contact module supplies 24v to the control circuit off of the 120v power.

@Aiph5u

This one? External IoT relay (FAQ)

The little green input on the side is like the control coil.

Yes, that’s the one. Sorry, I meant the requirements for it to properly interact with the open collector output. But probably won’t be necessary with the options above.

Thanks again

[Aiph5u (Aiph5u (not affiliated with Onefinity))]

Hey Martin,

@MVall

according to this U.S. manufacturer of relay modules, this 20A dry contact module supplies 24v to the control circuit off of the 120v power.

in this case, to attach it to open collector input, you just have to find out (by measuring, multimeter set to DC voltage) (or to ask the manufacturer) which wire is the DC positive. I would assume it is the red/white.

@MVall

I meant the requirements for it to properly interact with the open collector output. But probably won’t be necessary with the options above.

A power supply is necessary as the open collector output does not provide any voltage.