Proper/acceptable contactor usage

[kb58]

I'm building a CNC router and will use a contactor and power switches to control the 240V spindle power. 120V will be tapped off that to run the Acorn, C86, and servos.

I read that some here have wired the Estop switch into the contactor so that it removes power from the spindle and servos. I can see why (like what if a servo or spindle is on fire...). My question: might an acceptable middle ground be to wire the EStop in series with the VFD Stop Input, and count on the C86 board to shut down the servos if a fault is detected? I realize we're free to design and build our machines any way we want, but I want to pass this proposal by you guys in case I'm overlooking something important.

[ShawnM]

Just as you mentioned, you are free to wire the system anyway you like and are comfortable with. Use the contactor to break the COM wire on the spindle to stop it from spinning or interrupt the SPINFWD wire from the Acorn. Even without a contactor, when you hit the estop the acorn stops sending data anyway. Your spindle will stop and the drives stop, what else do you want to stop? I dont see the need to kill power to any of those devices. I have never wired a contactor to kill power to anything on a CNC machine. Oh, except when I power it down.

Just my 2¢

PS- if the machine is on fire I have other issues to worry about.

[kb58]

I'm finding more information on this topic buried within other threads, so I'm not sure how helpful having another one here is.

[cnckeith]

i would use the clearpath power hub and use estop to kill the power to servo drive and the vfd and any other powerful motor.
when i hit estop (not reset) i want everything except for the logic power (low voltage) to devices to be OFF immediately. that is definition of an emergency stop.

[Gary Campbell]

Why breakout 120vac when all of the devices you mentioned will run more efficiently on 240vac?

[ShawnM]

I run everything 220v also. I only break out 110 so I can mount a 4 gang outlet box on the machine for plugging other tools in and work off the table. Even your PC and monitor will run on 220.

[kb58]

Why breakout 120vac when all of the devices you mentioned will run more efficiently on 240vac?

I may in fact do so. It's not like there's much power being consumed within the control box, but duly noted. I do have several 115V outlets on the box already for various items, some of which do require 115V only.

[kb58]

i would use the clearpath power hub and use estop to kill the power to servo drive and the vfd and any other powerful motor.
when i hit estop (not reset) i want everything except for the logic power (low voltage) to devices to be OFF immediately. that is definition of an emergency stop.

The control box contains two IPC-5 power supplies, and while I do have a power hub, I figured that it can't work with two supplies, but maybe I'm wrong. Can just the one hub achieve the above, or will it require two hubs?

[Gary Campbell]

Why breakout 120vac when all of the devices you mentioned will run more efficiently on 240vac?

I may in fact do so. It's not like there's much power being consumed within the control box, but duly noted. I do have several 115V outlets on the box already for various items, some of which do require 115V only.

Make sure that you run all 4 wires to the controller (2 hots, neutral and ground) to the controller and load balance the 2 hot legs