AC Servo Controller Box design

[JAZZCNC]

Something along these lines will work.

In this setup, the E-stop circuit just uses an ordinary 4 pole relay wired to form a latching circuit, you could use a Safety relay to do the same job but these are expensive.
This circuit requires a momentary Reset button to be pressed before the E-stop circuit will latch on again after the E-stop has been pressed. This circuit could be expanded to include Limits or other safety features like cabinet doors open etc so that the E-stop cannot latch back on until all is safe.

When safe the E-stop circuit turns on the Master relay, this in turn, switches on the Drive relay, which then turns on all the contactors for the drives.
Depends on the power consumption of the drives to whether you use one contactor for all the drives or separate ones for each drive, personally, I would give each drive its own contactor rather than one large contactor. Similarly with the EMI filters, easier to use separate smaller filters than one large filter and probably cheaper.

The reason for using a separate relay for turning contactors on rather than directly from the master is so that other things can be switched on like lamps to show drives are on or anything else you may like. You'll also notice I use Terminal blocks TB1, TB2, etc is to make wiring simpler rather than trying to get several wires into one terminal.

Regards the VFD, then there is no point in cutting power to this in an E-stop situation because of how they work with draining the capacitors when power is dropped. It can also damage the VFD if done to often while the spindle is spinning.
They don't switch off instantly and stay powered until the capacitors have drained, also if the spindle is spinning at the time of the E-stop this then acts like a dynamo and feeds power back into the VFD/capacitors increasing the time before it powers down. It's much safer to send the VFD an E-stop signal which then will apply DC braking and stop the Spindle much faster.
You could if you wish to put a timer relay in the circuit which sent an E-stop signal to the VFD then after a set time dropped the power. This would be the safest way but in my experience, it's not required.

Also, note on the power side of the Servo I have drawn separate power lines L1, L2, and L1C and L2C.? It's common on servos to have power for the control logic of the drive but this should not be part of the E-stop circuit which is why it's drawn this way.

Hope this helps, there are many ways to do this, I'm not saying this is the best or safest way and each builder needs to decide what they want in terms of safety, etc, but this works and is safe without getting overly daft about it.