Branch wiring for menuboards

[dbowling]

I work as a consultant to a national quick-serve restaurant chain. They wish to upgrade their menuboards and have proposed that the boards be plug-and-cord connected to quad outlets within a wall mounted truss structure.

The proposed arrangement they provided shows a whip from the branch circuit into this structure to a quad outlet receptacle. Then several menuboards would plug into this outlet receptacle. This all seems to be reasonable until they then show the next quad outlet receptacle with a cord and plug that plugs into the first quad.

There are a total of six quad outlet receptacles for the menuboards and each quad outlet receptacle is fed from the previous one via a cord and plug. I have looked thru the Code and cannot find anything specific related to this wiring method, but it just does not seem Code compliant. Almost seems like using made-up extension cords for a permanent branch wiring system.

Is this an acceptable wiring method? If not, can anyone direct be to the Code reference(s)?

 

[Volta]

Well, might be easier if we read them out of order here. We can only use the cord + plug method if we comply with 3, 6, or 8 below, unless specifically permitted elsewhere.

"400.7(B) Attachment Plugs. Where used as permitted in
400.7(A)(3), (A)(6), and (A)(8), each flexible cord shall
be equipped with an attachment plug and shall be energized
from a receptacle outlet or cord connector body."

I don't think this situation warrants it.

"400.7 Uses Permitted.
(A) Uses. Flexible cords and cables shall be used only for
the following:
(1) Pendants
(2) Wiring of luminaires
(3) Connection of portable luminaires, portable and mobile
signs, or appliances
(4) Elevator cables
(5) Wiring of cranes and hoists
(6) Connection of utilization equipment to facilitate frequent
interchange
(7) Prevention of the transmission of noise or vibration
(8) 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
(9) Connection of moving parts
(10) Where specifically permitted elsewhere in this Code"

 

[goldstar]

I just worked in a Dairy Queen that had the same situation. All the menu displays are modular and come with their own cord & plug attachment. If you're ganging them together they have internal Molex connectors so that you can plug several displays together off of one cord and plug. The only problem I had with the original installation was that the receptacle provided (although properly wired) was in a junction box laying above the hung ceiling. That cheap, little 16 gauge cord was poked through the hung ceiling tile and plugged into that receptacle. In all fairness these are 3-lamp, 24" fluorescent bulb fixtures and the draw on the ballasts is probably 0.2 amps. You'd probably have to put 30 of these on one cord before you had a problem. In my case I ran directly into the receptacle with MC and then to the new display.

 

[Ponchik]

I don't see a problem if the menuboards come prewired with cord and a plug.

 

[steve66]

I think its 400.8 that says flexible cord can not be used as a substitute for permenent wiring. Sounds to me like that's what they are doing, unless all the flexible cords are part of the listed signs.

Sounds to me like they need to hardwire the power to each quad.

 

[dbowling]

I agree that if the menuboards come with the plug & cord then it is okay. The issue was the branch wiring between the quad outlet receptacles being connected to each other via a cord & plug. I think the reference to 400.7 and 400.8 answers that concern that this is not compliant with Code for branch wiring.