120v motor with 24vac motor control quesiton

[mstrmp3]

We install automatic gate operators which use 120v motors and 24vac control circuits. When we need to use 2 operators in a master/slave combination to span a large width driveway, the manufacturer supplies the operator with a 40ft cable consisting of 7 14AWG stranded conductors. 3 of those conductors are motor for the motor (120v cond to open, 120v cond. to close, and a neutral) the other 4 conductors are 24vac motor limit wires. We have been told by an inspector that we have to run two separate conduits and separate the 120v from the 24vac. Is this accurate?

I know that if they were separate conductors, we would have to separate them, but if they are in a pre-made cable we would not.

 

[wirenut1980]

I think the cable would have to meet one of the exceptions in 725.136. If the cable is supplied by the manufacturer, one would think it meets the exception?

 

[tom baker]

The inspector feels the 24 volt is "low voltage" which is the wrong term, but the rules for this are in Art 725. Art 725 has three types of remote control, signaling and power limited circuits.
Class 1 is has power limited and non power limited
Power limited is limited to 30 volts AC, non power limited is not limited by voltage. Class 1 circuits are wired in chapter 3 wiring method. A common use of Class 1 is for electric heater 24 vac t-stat control
Non power limited is typically motor control circuits. You can mix a class 1 with functionally associated power conductors.

But Class 1 must be wired with a chapter 3 wiring method, which flexible cord is not, however there are some exceptions in Art 400

Class 2 and 3 are what we typically refer to as low voltage. They require separation from power and lighting circuits, I don't see this as a class 2 or 3 application.

Do this
Look at the equipment, does it state what class wiring to use
Better yet is the entire operator listed and labeled? If so you are OK as long as you follow the instructions.
And call the mfg and get them to help out. I would hope they understand the NEC and UL requirements

 

[LarryFine]

Mr. MP3, welcome to the forum!


I suggest passing the inspector's comments on to the gate equipment supplier, have them deliver what the inspector will accept, and a change order to the customer for additional work.

Then, if/when sparks fly, introduce the customer to the inspector, and tell them you'll abide to whatever they agree on, and get paid to do. You shouldn't get stuck with this headache.

My personal feeling is that, once you deliver power to the master unit, the cable connecting it to the slave unit is part of the assembled system, and it's between the manufacturer and UL.