[dazp1976]

If your 24v DC is powering the Brain of the machine you don't cut power to that, High voltage AC and 24vDC switching on the same contactor is not a good idea, some contactors have Auxiliary Contacts on the side that could be used for switching the 24v DC

I'll get anther small unit for the DC then. Hasn't got an aux on my current one.
Keeping the brains powered is the idea.

The control stop circuit is basically the line that runs to the board input that tells it the MC is stopped (I10 being the norm if using pport board).

So now I've got:
Magnetic #1: A1/A2 EStop = 220vac
T1 Spindle Servo main power = 220vac +
T2 Stepper 60v x,y, psu) = 220vac +
T3 Stepper 80v z, psu = 220vac +

Magnetic #2: A1/A2 EStop = 220vac
T1 control stop circuit = low 24vdc (I10 reset fault)
T2 Aux
T3 Aux

I'm sure I'll find something to go on the aux.

All UC300eth/UCBB/auxiliary opto plc boards (brains) are still on, powered by separate 24v/5v supplies.

[dazp1976]

I'll get anther small unit for the DC then. Hasn't got an aux on my current one.
Keeping the brains powered is the idea.

The control stop circuit is basically the line that runs to the board input that tells it the MC is stopped (I10 being the norm if using pport board).

So now I've got:
Magnetic #1: A1/A2 EStop = 220vac
T1 Spindle Servo main power = 220vac +
T2 Stepper 60v x,y, psu) = 220vac +
T3 Stepper 80v z, psu = 220vac +

Magnetic #2: A1/A2 EStop = 220vac
T1 control stop circuit = low 24vdc (I10 reset fault)
T2 Aux
T3 Aux

I'm sure I'll find something to go on the aux.

All UC300eth/UCBB/auxiliary opto plc boards (brains) are still on, powered by separate 24v/5v supplies.

Ahhhh. Nevermind about a second magnetic contactor.
Just realised I have some ice-cube power relays.
I can tie them in series to the A1/A2 Estop button line of contactor #1 and they can then be used to trigger the I10 reset fault.

So 220vac+ > 3A fuse > A1/A2 magnetic > A1/A2 ice cube > Estop button > 220vac-
Magnetic #1 T contacts as above.
Ice cube - I10 control board reset/stop fault.

All this agro because a 24vdc contact unit is just too slow acting. Annoying.

[mactec54]

Ahhhh. Nevermind about a second magnetic contactor.
Just realised I have some ice-cube power relays.
I can tie them in series to the A1/A2 Estop button line of contactor #1 and they can then be used to trigger the I10 reset fault.

So 220vac+ > 3A fuse > A1/A2 magnetic > A1/A2 ice cube > Estop button > 220vac-
Magnetic #1 T contacts as above.
Ice cube - I10 control board reset/stop fault.

All this agro because a 24vdc contact unit is just too slow acting. Annoying.

You sure it is the 24v contact acting slow, or just the normal thing that happens when you turn off a SMPS these power supplies can take some time to drain the power from the circuits, and may appear that the switching relay is not doing its job

You should start your own Thread if you need to post more about your system