Upgrading to 80mm Spindle and 2-stage 1250CFM Dust Collection system. Went with PwnCNC and got their IoT power strip that will provide power to the water pump and dust collector automatically. However, the dust collector will also service the table saw, spindle sander, belt sander, hand sanders, etc. So, I need to have a way to turn it on manually as well.
What I have mapped out in my head would be to have a SPDT switch (Single-Pole, Double-Throw) that is normally left connecting power to the dust collector via the IoT Power Strip. When the FVD powers on the dust collector comes on with the water pump. And then, if I need to use the dust collector for something else while the spindle isnāt running, I would just throw the SPDT switch and the power supplied from a normal outlet (always hot) would power on the dust collector.
I have a rough sketch but not sure how to post a photo here. My though is that the Neutral and Grounds are all connected and the Hot/Common Black wires are connected to the switch. Iām going to run this by my electrician (who does all my final cutovers on non-easy jobs after I run the wiring) but looking for some feedback before I go in this direction.
Any thoughts from the brain trust here? (Iām looking at you @Aiph5u and the other regularsā¦)
I have a similar situation. I unplug the DC from the socket i use when using the CNC and plug it into a different mains socket and switch it on from there.
if you really want to collect dust from the usual machines in a carpenter/cabinetmaker/wood workshop with a professional dust collection system, usually you have an automatic dust collection startup, e.g. like this one which uses electromagnetic sensors over the power cables to sense if there is current to the motor of a machine, (would work with spindle cable too), and which also switches the sliding gates.
But to your question with the switches/relays:
First I would not switch the dust collection and the spindle coolant pump by the same output, because in some situations the coolant on the spindle needs to run when the dust collection does not. E.g. the spindle coolant would continue to cool after the spindle was stopped as long as the spindle is still hot or warm, or, when you mill non-ferrous metals, the dust collection is useless and you would not want it to run (while spindle coolant pump of course has to run) but instead switch on workpiece air cooling or workpiece fluid coolant/lubricant nozzle with M7 or M8 (this creates another problem that is solved here).
As far as I know the VFD PwnCNC sells has only multi-purpose relay outputs but no open-collector outputs, so I am not sure if your IoT relay (FAQ) will work on those VFD outputs. Relay outputs on VFDs are usually SSRs which are not really relays but semiconductors (thyristors or triacs) which need a minimum load current to flow to reliably hold their state, but the IoT relay advertises that its control input draws only absolutely minimal current. I say āusually the relay outputs on VFDs are SSRsā, but you can ask Daniel @PwnCNC if this is really the case on his PwnCNC VFD, or ask him if he connects a relay on these programmable multi-purpose relay outputs or other loads. With their max. 3 A current @250 V, these outputs cannot drive a shop vac or a dust collector directly as that would be 660 W maximum at 220 V (they could drive a coolant pump though).
Usually on a VFD, you use the open collector outputs to control the spindle coolant and dust collection relays. But as far as I can see the DELIXI CMD-EM60 has none (am I right?) And I would use real relays, e.g. Omron G4A (can switch 20 A).
The VFDs Omron MX2 and Hitachi WJ200 (which are practically identical), but also many other VFDs, have two open collector outputs (here called ā11ā and ā12ā):
Regarding the wiring of two switches that switch an electric device like dust collection on, what you describe with a SPDT (1 x UM, Wechsler) switch requires that you manually have to decide who gets the dust collection. Also you switch only one conductor (switching both is better). But you could also put the switches in parallel. A relay is also considered as a switch here, e.g. with two DPSTs (2 x EIN, SchlieĆer), of which one is a relay:
I was under the impression that the IoT power strip would let me program the outlets separately such that I could turn off the Dust Collection with some G Code and leave the water pump on for a little longer if need be through other G Code. Though I wonāt be milling metal initially, I am leaning into some very dense hardwood and the idea of cooling running after the spindle turns off makes sense.
Iāll reach out to Daniel as you suggest.
Just a little more learning curve in what appears to be a never ending demand.
Looks like Daniel has a new helper/employee that answered his support email.
Clinton indicates that the āNormally Onā and āNormally Offā outlets on the IoT Power Strip are using (what sounds like) a powered SPDT switch already. So, I can just make a āYā power cord that are connected to both outlets (the āNormally Onā and one of the āNormally Offā) and join them together into the receptacle feeding the Dust Collector plug. Sounds kind of scary to join them together but he insists that they physically can never be on at the same time. Anyway, would make for an easy solution.
And the other Normally Off outlet would go to the water pump. He indicates that if Iām not cutting metal then Iāll never need to worry about my spindle getting too hot that it needs post-cut cooling. Even an air cooled model (which has an internal fan that stops when the spinning stops) would likely have been fine for hardwood carving applications. If I ever get into the metal world, I can re-investigate. I guess the benefit me getting the water-cooled is that Iām not sucking any air (and lots of dust) into the spindle, yeah?
but this āsolutionā, to power the dust collection in both states, would mean that the dust collector is always on, regardless of how the relay is switched. That makes no sense.
Also what we talked about was something different: To trigger the control input of the IoT relay. The question was whether the outputs T1A, T1B and T1C on your VFD are real relays or just SSRs. Did you ask this? If the first is the case, you can connect these outputs directly to the IoT relay control input and let the VFD control the dust collector.
What you can do in any case, independently of whether these outputs on the VFD are real relays or SSRs, is to connect the spindle water coolant pump to it, because unlike the IoT relay, you can consider a coolant pump to always draw the minimum current anyway in order to ensure the SSR holds its state. This would mean you would use the internal relay/SSR of the VFD to switch the spindle coolant pump (and itās designed to be made this way) and you need no external IoT relay for this.
Unfortunately, connecting also the dust collection directly to this output of the VFD is not possible as it is limited to 3 A (see diagram above) and a dust collector draws much more. For this you would need the external, IoT, relay.
Usually the dust collection is turned on when the CNC program encounters a M3 (start spindle) command. However connecting the IoT relay control input to the programmable control output of the VFD would be good since the ātool-enableā pin 15 on Onefinity Controller I/O port that gets active when M3 is encountered, only works when the ātool-typeā on TOOL page is set to āRouterā or to āPWM Spindleā, but it is not working when you have the ātool-typeā set to a VFD, because it is assumed that the VFD then controls such things.
With the āUploadā icon in the message composition window (7th icon from left)
@Aiph5u Arghh. Youāre right. Duhā¦ It would be on all the time.
I havenāt asked Daniel because I didnāt have a real idea of what the difference was. Iām trying to figure it out. The documentation says that once the spindle is over 5K RPM or so the IoT should switch on. So, Iām thinking itās not a true relay on the VFD but the IoT is just sensing any type of current.
Iām trying to keep it as simple as possible (and need to as the learning curve is steep enough). Hereās the very basic diagram of the wiring that Iām considering. My electrician says this will work; as in it wonāt blow anything up. I just want the VFD to switch on the current on its side when the spindle is running and when I pull the switch in the other direction, then the current is on no matter what the spindle is doing. And I can put it in the middle if I ever not want it the dust collector on.
as I already said above, with this circuit, you would have to choose and decide everytime which source uses the dust collector. With this circuit, if you put the switch to the always on socket, it gets separated from the CNC. This means, everytime you want to use the CNC, youāll have to take care that the switch is in the right position. This is not necessary. If you consider that in my better circuit shown above, you have the same components as in your image, but just wired differently, you can have a solution where you donāt have to alter the switch prior to using the CNC. The CNC would always be able to switch the dust collector on, and switching it on for the other devices is the option for which you would use the switch.
The question is in fact here is another. The IoT relay, as all relays, has a control input that switches the relay between the two positions. The question is, is the programmable multi-function relay output T1A-T1B on the VFD able to hold this IoT control input in the active state, or not? It will surely be able to hold its state when attaching the pump (directly) to it, but can it hold the state of the IoT relay control input? As explained above, if the T1A-T1B output of the VFD uses a SSR, it may have problems with holding its state regarding the extremely small current the IoT relay is advertised, whereas if itā a real (electromagnetic) relay in the VFD, there would be no problem.
One way to find this out is to power the VFD and click or send it a FWD RUN command. In the default configuration, the P2.0.29 setting is set to RUN condition, so the ānormally openā multi-function relay output T1A-T1B would change to āclosedā as soon the VFD is set to RUN spindle (and this would switch a spindle coolant pump or an external relay on). So if inside the VFD, itās a real (electromagnetic) relay, you will hear a āclickā noise. If not, itās not a real relay, but a SSR. This works like a relay too, but is expected to have difficulties to hold its state when only a very small current flows, and unlike a water pump, the IoT control input is advertised as only requiring an extremely small current.
So one way to find this out is to hear if it clicks when you press RUN, or not. Or ask Daniel @PwnCNC.
From a National Electrical Code perspective there are issues with your design, you are potentially bonding together the neutral from two different branch circuits which is not permitted and would play hell with GFCI and AFCI systems. I would suggest at a minimum you use a DPDT switch to also isolate the neutral and ensure all power components are rated for 250vac (due to the potential to plug into 2 branch circuits on different sides of the split phase power) and appropriate amperage for the load.
Iād second the idea of using a SSR or contactor with low voltage control wiring to activate it with a centralized switch or switches at point where you need them (or VFD/Controller on/off)
Thanks a ton, you two! Yes, I could go with a Dual-Pole/Double-Throw and throw the neutrals as well. Probably a better idea if I went in that direction.
However, I respect your guyās expertise and will try to go the way youāre suggesting but Iām still trying to grok Aiph5uās design.
So, āRel 1ā is a 24V powered DPDT Relay that Iād buy. (Powered by a 24V power supply with a resistor and a diode for the power that Iād pick up as well.). This would be a true relay that would be triggered by the VFD. The two DPDT switches (one auto and one manual) would then be acting like a three-way light switch in that if ever the power was not activated by the VFD/spindle and I wanted it on, Iād flick the manual switch and it would come on/off. Is all that that right so far? Or is āRel 1ā the relay in the VFD?
Now, (if itās a new relay that Iād buy), what if the spindle was on (and thus the dust collector as well) and I wanted to use the table saw (for example), Iād just open its blast gate start cutting on the table saw. But what would happen if the CNC happened to finish a cycle and wind down while I was cutting on the saw? Wouldnāt it turn off my dust collector? Or am I thinking of it wrong?
@PwnCNC Hey Daniel or Clinton, would you be so kind to have a peek at what we are discussing here?
Thanks again for helping. I donāt think Iād get near as much accomplished on my 1F without you guys on this forum. Best beginner tip is to spend a lot of time here!
Aiph5u
(Aiph5u (not affiliated with Onefinity))
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Hey Jim,
yes, with the only difference that this circuit shows an open-collector output on the VFD. You could imagine that instead of a 24 V relay, you would want to use your IoT relay here. Itās a relay after all. Itās just that you have no open collector outputs on your VFD but just a relay output (T1A - T1B - T1C). Youāll have to try if the IoT relay can be switched reliably by this output. T1A-T1B is the ānormally openā part that gets closed on VFDās RUN command so would power the control input of the IoT relay, just as the 24 V relay shown in my circuit diagram. The control input is the little green two-pin port on the side of the IoT relay.
yes
no, itās an external one.
No, since even if the CNC was working and had already switched the dust collector on automatically, prior to use the table saw you would switch the manual switch on. This would have the effect that when the CNC finished and switched the relay off, the dust collector would stay on.
