7i76 VFD Starter relay Question

Wiring question

Changing an existing setup and about to wire the VFD

Pretty normal stuff
Currently (existing) the machine has a start button (120v) that activated a magnetic motor starter that switches both lines (220v sinngle) that are being fed to the VFD
The coil has an e-stop (NC) wired into it to break the loop that keeps it on after the button is pressed.
The power supply for the gecko drives has basically the same setup except 120v instead of 220v

I've changed the 2 e-stop switches so that one switch has 2 separate NC contacts and it will break both magnetic starter loops, still two buttons to turn on either the drives or the spindle VFD

Anyway, both of these systems can currently be powered up without the 7i76 control being on and LinuxCNC running...

Is there a relatively straight forward way of making sure the computer part of the system is up and running prior to allowing the power to start the two 120v relay coils?

I didn't really want to add a relay to control the relays......
Thanks
M

I suspect you would have to add a small 7I76 driven DC relay
(or small SSR) to your EStop loop to switch the 120 VAC
contactor coil

Digging through my boxes of hardware now hoping that I might have a small relay but I suspect everything I'll have will be too small or will have a 120v coil as well

I think I remember the 7i76 has an "enabled" pin out somewhere or should i use a 24v "switch" on the 7i76?

Thanks again
M

Yes, there is a spindle enable, but if you want a more general EStop loop
enable, it would be better to use a field output to drive a relay or SSR.

(A SSR has the advantage of not requiring an arc suppressor)

I've planned on using the spindle enabled for the actual VFD enabled so for this I think I'll go with the 24v field output. I don't have any suitable relays on the shelf so I'll have to buy something, might as well be a SSR (or two, doesn't seem like DPDT are very common)

I'm only using 2 of the 3 contacts on the existing relays, I guess I could wire the spindle one through the drive one and control the drive one through a single SSR. That way the drive would have to be on before the spindle could be powered up as well... might not be a bad thing

Thanks again for the sanity check.
Stay tuned for questions on setting the HAL for the SSR
M

Update
Solid state relay (3-32vdc coil - 120vac 10A, (all I could get locally)) installed and hooked to pin 24 of TB6 on the 7i76
PncConf 7i76 (SS#0) Output 07 set to Machine is Enabled

Working perfectly

Moving ahead