Flexible cord to a motor

[FittsJ2]

I am hooking up some industrial screw press machines that need to be feed from a junction box above the equipment.

I know article 400.12(1) says flexible cord cannot be used for fixed wiring, but the second sentence in article 430.6 says “Where flexible cord is used, the size of the conductor shall be selected in accordance with 400.5”. Does this mean that I can run flexible cord (SOOW for example) to the motor, from the above j-box, or would I have to use FMC or LFMC?

 

[zbang]

You'd use cord if the machine is portable and moved frequently (and plug connected), but for a fixed-in-place machine you need "fixed" wiring. Also be aware of the support limits for the various types of flex- it's common to drop EMT or RMC down from the ceiling and transition to flex for the last couple of feet.

 

[kwired]

I am hooking up some industrial screw press machines that need to be feed from a junction box above the equipment.

I know article 400.12(1) says flexible cord cannot be used for fixed wiring, but the second sentence in article 430.6 says “Where flexible cord is used, the size of the conductor shall be selected in accordance with 400.5”. Does this mean that I can run flexible cord (SOOW for example) to the motor, from the above j-box, or would I have to use FMC or LFMC?

I presume where you said 400.12(1) you meant 400.8(1).

That says "As a substitute for the fixed wiring of a structure"


400.7 gives you many possible reasons why you may use flexible cord from your equipment to a point near that equipment. Other parts of 400.8 tell you a few ways you can't utilize flexible cord though you may still be able to use flexible cord for your application.

Not knowing much more about your application, many times a drop from directly/nearly directly above and not passing through walls, floors, ceilings or through doors or windows will generally be acceptable.

Portions of 400.7 that may easily apply are pendants, Connection of portable luminaires, portable and mobile signs, or appliances, Connection of utilization equipment to facilitate frequent interchange, Prevention of the transmission of noise or vibration, Appliances where the fastening means and mechanical connections are specifically designed to permit ready removal for maintenance and repair, and the appliance is intended or identified for flexible cord connection, or Connection of moving parts.

 

[FittsJ2]

I presume where you said 400.12(1) you meant 400.8(1).

That says "As a substitute for the fixed wiring of a structure"


400.7 gives you many possible reasons why you may use flexible cord from your equipment to a point near that equipment. Other parts of 400.8 tell you a few ways you can't utilize flexible cord though you may still be able to use flexible cord for your application.

Not knowing much more about your application, many times a drop from directly/nearly directly above and not passing through walls, floors, ceilings or through doors or windows will generally be acceptable.

Portions of 400.7 that may easily apply are pendants, Connection of portable luminaires, portable and mobile signs, or appliances, Connection of utilization equipment to facilitate frequent interchange, Prevention of the transmission of noise or vibration, Appliances where the fastening means and mechanical connections are specifically designed to permit ready removal for maintenance and repair, and the appliance is intended or identified for flexible cord connection, or Connection of moving parts.

I meant 400.12(1). I’m using the 2017 code book, 400.10-uses permitted, 400.12-uses not permitted.

The equipment I am hooking up is in the middle of the building with no way to run conduit to other than overhead. The drop from the J-box on the trusses to the motor will be about 10-15ft. Can I only use flexible cord to the motor if it meets the requirements of 400.10? If that’s true, then is 430.6 only referencing a motor connected with flexible cord that meets the requirements of 400.10?

 

[Srv52761]

If it is coming from above, check 368.56(B).

 

[kwired]

If it is coming from above, check 368.56(B).

Are you saying OP must use busway to be able to drop with a flexible cord??

400.7 (A)(1) and apparently has moved to 400.10 in 2017 (I was using 2014 with previous comments mostly because I don't have an electronic version of 2017) allows "pendants"

NEC does not define pendant, so that leaves us with a dictionary definition, I find "something suspended" to be one definition - seems a drop supported by something above would fit that definition.