Cord length vs conduit

[Stephen.Kosek]

I am developing a product, and I have a question about compliance regarding NFPA 70 cord length.

My question: In a warehouse, loading dock doors are 20 feet tall. I wish to sell and install a 120V motor to the manual doors, thus automating them. My motor will have a 25 cord to plug into a socket near the floor. I want to avoid conduit installation. Does NFPA 70 require conduit? What is the chapter and verse that requires conduit?

 

[petersonra]

Your product would probably have to be ul listed so the answer to your question is likely to be found in the UL product standard for this kind of product. It is unlikely they will allow for a cord at all, but certainly not one that is 25 feet long.

Just curious why you think there is a market for another garage door opener when there are a bunch of people making them already.

 

[zbang]

To a certain extent, you're into UL land and out of the NEC, which generally stops at the receptacle. However...

400.12 Uses Not Permitted. Unless specifically permitted in 400.10, flexible cables, flexible cord sets, and power supply cords shall not be used for the following:
(1) As a substitute for the fixed wiring of a structure
(2) Where run through holes in walls, structural ceilings, suspended ceilings, dropped ceilings, or floors
(3) Where run through doorways, windows, or similar openings
(4) Where attached to building surfaces
Exception to (4): Flexible cord and flexible cable shall be permitted to be attached to building surfaces in accordance with 368.56(B) .
(5) Where concealed by walls, floors, or ceilings or located above suspended or dropped ceilings
Exception to (5): Flexible cord and flexible cable shall be permitted if contained within an enclosure for use in Other Spaces Used for Environmental Air as permitted by 300.22(C)(3).
(6) Where installed in raceways, except as otherwise permitted in this Code
(7) Where subject to physical damage

422.16 Flexible Cords.
(A) General. Flexible cord shall be permitted (1) for the connection of appliances to facilitate their frequent interchange or to prevent the transmission of noise or vibration or (2) to facilitate the removal or disconnection of appliances that are fastened in place, where the fastening means and mechanical connections are specifically designed to permit ready removal for maintenance or repair and the appliance is intended or identified for flexible cord connection.

You may also hit something in article 430, but I'm not diving in there right now.

So generally, while the NEC doesn't require conduit, it does prohibit the use of a flexible cord.

 

[petersonra]

To a certain extent, you're into UL land and out of the NEC, which generally stops at the receptacle. However...






You may also hit something in article 430, but I'm not diving in there right now.

So generally, while the NEC doesn't require conduit, it does prohibit the use of a flexible cord.

It sounds to me like the motor would be mounted on the moving door so I think the code might allow it. I don't think a cord is the right application for something like this though. Festoon cable is maybe a better option.

 

[tom baker]

You definitely want to have a NRTL listed product. UL is the most common but there are others. The NEC would cover the wiring to the opener or receptacle it plugs into