I was looking at the AN003 Note about controlling machine power and was wondering if the emergency stop switch in the diagram operates at 24v or 120v?
The E-Stop switch(es) shown in those diagrams operates at two different voltages. The top section(s) which are connected in series with the contactor coil operate at the AC mains voltage (120VAC or 230VAC). The bottom section(s) which are connected to the PMDX-126's E-Stop input operate at +5VDC.
I'm looking to stop my spindle and stepper motors if the E-Stop is hit. I'm controlling my spindle with a VFD and my stepper motors are powered by a 48v power supply. Would I cut power to both of these if an E-Stop is hit?
Yes - that is the purpose of this circuit. Pressing the E-Stop switch immediately cuts power to the motors and spindle. It also causes the PMDX-126 to disable its outputs and sends an E-Stop signal to Mach3. But the circuit does not rely on electronics on the PMDX-126 nor software on the PC to disable the motors.
What kind of contactor is needed to wire my machine like the diagram in AN003?
That depends on how much total current your stepper motor power supply and VFD draw. Our Contactor18-120 (
http://pmdx.com/Contactor18-120) would work for this case if the total current requirements are 18 Amps or less. If you need more that 18 Amps, you can use two of these contactors. You would wire the power input and coil terminals (those on the left side of the contactor in the drawing) in parallel, and connect the "output" relay contacts (on the right side of the contactor in the drawing) from one contactor to your stepper motor power supply and the contacts from the other contactor to the VFD power supply input.
Also if the E-Stop is hit in Mach3 does it cut power to what ever is hooked up to the contactor?
Yes, if you have the PMDX-126 and Mach3 configured as shows in that app note. The only time the that power will be enabled to your motors will be when Mach3 is running and the "RESET" button is *not* flashing.
Bob
