How can I add an end switch to carraige system

[epcole]

I have a carraige being operated by a transmission drive on a 120v 3ph 2hp motor. I am using a magnetic contactor, followed by a reversing drum switch (a later addition when they didn't want to push the cart back after each run). Now they want to add a switch down by the end of the tracks to break the circuit when the carraige passes a certain point (in case the operator isn't paying attention). How can I do this? I thought about wiring it via the coil power but the switch needs to be almost 80ft away, which in both directions will be 160ft and will require a very big wire size to avoid the voltage drop. I wish all of these things were addressed when they designed the system instead of adding all of this now. Any idea how I can do this?

 

[schip666!]

A big relay to operate the motor, and a small switch with small wire to operate the relay? You could also use the relay as an emergency shutoff, which you didn't mention and is probably required by some OSHA factotum someplace.

You magnetic contactor should work as the relay if you wire whatever runs it in series with the down-range switch.

 

[dlgoff]

If the motor has a start-stop switch arrangement, just extent the loop to the end of your carriage system and add another stop switch (micro-switch perhaps). I would think the motor starter coil that is switched on or off operates at a low voltage?

Edit: If you are using a motor starter like this, you can string as many stop switches in the loop as needed.

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