Use a separate Relay and have the VFD fault Signal turn it on when goes active. Run the E-stop signal thru NO contact.
new small issue/confirmation : regarding ground, it is best to have one point for all ground right? meaning if chassis of one device is grounded and the whole sheet is grounded, I should not wire the ground connections of other devices if they also ground their chassis right?
in first photo you can see I have connected the power supply chassis to ground wire which goes back to main ground point ( distribution terminals ) so the whole back is grounded. in second photo VFD and power line filter have earth connections but by checking continuity test already these points are connected to back also. so should I skip connecting ground wire to them?
after some research I realized that all ground contacts should be connected and not rely back panel, anyway I need confirmation of another issue please
when connecting the VFD with contactor, should all wires ( L,N,Gnd) be connected through the poles or can I just connect the Live with contactor and rest direct from mains power?
what about the DC output power supply for the drivers?
I personally would not connect the mains VFD through the contactor but would just connect the signal wire to make it stop.
The DC output from the power supply should not go through the contactor either .
Perhaps you should find somebody local to give you some help with this before you get a chance to damage it all or yourself.
Last edited by Clive S; 20-01-2016 at 11:44 AM...Clive
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If you still want to include a contactor to the VFD, then I'm pretty sure that if you hit the e-stop (and turn off the mains power to the VFD) it will not like having the spindle spool down and feeding power back into it when it is not on. Would it damage it? Not sure. But I wouldn't risk it myself.
I see in one of your earlier posts that you have a braking resistor, which can allow quicker ramp downs (although I've not used mine as it is plenty quick enough without). If you plan to use it I would imagine that killing the power to the VFD would not allow it to use the resistor and it would coast down over a much longer period.
So if you still want to do this I think you would need a delayed timer on the contactor to switch it off after say 5 seconds, depending on your ramp down parameters. This adds complication, but I know Dean has done this so it is possible. This is in addition to the e-stop logic signal telling the VFD to stop, which you would do first to stop the spindle safely under VFD control.
I seem to remember reading some time ago that you can be specific and tell the VFD that this is an emergency (not just a regular stop / start command) and it will do an emergency ramp down / stop which is quicker.
Last edited by routercnc; 20-01-2016 at 09:03 PM.
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Also you won't be able to start cutting straight away after a reset and will need to wait for VFD to power up fully which could be pain.
If you really do want the VFD turned off then I would have the VFD tied to E-stop but keep it separate from HV enable. Just have HV enable control the drives PSU and the Spindle RUN Command.
This way when Mach3 is in Reset mode then the VFD stays on but can't started until mach is reset. At which point HV enable turns on the drives and allows spindle RUN signal to reach VFD when needed.
Think of it has two separate systems working together. E-stop is hardwired and kills everything, HV enable just kills Drives and Run etc but only when mach is in Reset.
There are many times you'll want some things powered while Mach is in Reset mode. Ie Vacume but at same time your not in E-stop condition.
thank you guys for the insight and preventing me from making a mistake, I guess the VFD manual confused me because it has some notes about when using a contactor. so in this case is there use for a contactor (for the VFD) at all if controlled through a constant turn on signal?
appreciate your input on following related subject as well: at the moment the planned way to start/stop the spindle is through input signal coming from CSMIO (the usual way) , in case of problems and I hit E-Stop, naturally CSMIO will disconnect that signal and spindle will stop normally.
is that sufficient or should I utilise the other input ports of my VFD, it has a total of 8 ports to accept commands from a controller.
they are as following:
0 - No Effect
1 - first multi speed ( references a table in the manual )
2 - second multi speed ( references a table in the manual )
3 - third multi speed ( references a table in the manual )
4 - frequency rises
5 - frequency decreases
6 - forward jog
7 - reverse jog
8 - forward ( this is what I used before and works fine and is enough to start/stop it )
9 - reversal
10 - forward trigger
11 - reverse trigger
12 - stop
13 - freely shutdown
14 - forced shutdown
15 - forced inversal
16 - counter is cleared
17 - counter input
18 - program run reset
19 - external fault
20 - external reset
21 - accelerate and decelerate - time choosing first ( references a table in the manual )
22 - accelerate and decelerate - time choosing second ( references a table in the manual )
23 - accelerate and decelerate pause
24 - force ACI passage effective
I don't understand most of them but its a direct copy-paste from the manual.
so is it worth doing a setup where one of those functions is triggered during E-Stop? maybe the stop or external fault? hehe feels like overthinking things
This to me suggests that you only need one power supply if you are just switching small loads, such as relays, and a decent size capacitor across the power inputs would remove any ripple, which might cause problems.
I do not intend to go the extra expense of a second power supply unless absolutely needed.
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