Different Voltages in a multiconductor cable

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mull982

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I have a 30/c #12 multiconductor cable. In this cable there is going to be 120V and 480V on the various conductors. Is there allowed to be different voltages run on the different condcutors of a multiconductor cable. Does the NEC address the issue at all? Is this a good practice?

The 480V will be for motor feeds, and the 120V will be for motor control circuits. I am concerned about possible induction from the 480V onto the 120V thus possibly not allowing the motor control circuit to drop out a contactor or give a false reading on an I/O point. The cable run is a couple hundred of feet.
 
Motor runs using composite cable is acceptable however in the last 8 to 10 yyears in my experience most clients are shying away from it for simplicity sake and ease of installation. The motor will drop out fine at 200 feet,,,,,,,,,there is a phenomena called capacitive coupling where it will not drop out but this needs to be in the 1200 feet plus lengths, when a remote stop button is bridged by the capacitive effect. That is rectified by useing DC voltage for control or special long distant control relays or later tecnology of smart starters.

dick
 
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