Temporary Service Flat Cable

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Brunz

Member
Location
Harrisburg, PA
I am trying to purchase bulk quantities of flat 12-3 cable/cord to use for temporary connections similar to entertainment purposes. The only thing that I can find is pre-made flat extension cords. I would like to make custom lengths and terminate the ends myself. Anyone have any ideas? And is there anything wrong with running this cable under carpet for temporary power?
 

iwire

Moderator
Staff member
Location
Massachusetts
And is there anything wrong with running this cable under carpet for temporary power?

Yes, there is.

It is hack, it is a hazard and it is a violation.

400.8 Uses Not Permitted. Unless specifically permitted
in 400.7, flexible cords and cables 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 cable shall be permitted
to be attached to building surfaces in accordance with the
provisions of 368.56(B)

(5) Where concealed by walls, floors, or ceilings or located
above suspended or dropped ceilings

(6) Where installed in raceways, except as otherwise permitted
in this Code

(7) Where subject to physical damage
 

Brunz

Member
Location
Harrisburg, PA
I am aware of the hazards involved with running flexible cord especially in a permanent setting. This is strictly temporary. I do not agree and have tried to fight these installations altogether. I am not doing this on a voluntary basis, I am being forced into it. In the past we have run regular so cable. This presents major tripping hazards. The installations are being done to set-up for an Auto Show, where the cords are run from distribution panels under carpet to power pylons and vehicles. Isn't there somewhere in the code to dictate regulations for temporary instalations?
 

Brunz

Member
Location
Harrisburg, PA
We set shows everyday, this is the only one that we run power along the floor. The problem with this particular show is that there are no ailes. It is a very open floor plan. If we tried to use yellow jackets, it would require thousands of feet. We tried to drop power in from overhead, the promoter and dealerships do not want power hanging down from the ceiling. I ruins the "atmosphere". Plus the way that the displays are set-up, all the access for power are from underneath. I know that we are not the only facility that runs power along the floor for events such as these, I am looking for a way to make it as safe as possible or to find solid reasoning to refuse this kind of install altogether.
 
We set shows everyday, this is the only one that we run power along the floor.

This is extremely common in event centers, big and small.

We tried to drop power in from overhead, the promoter and dealerships do not want power hanging down from the ceiling. I ruins the "atmosphere".

Sometimes they have to choose between power and looks ;). IME, the exhibitors don't get a choice of how the power is run, just whether or not they want it. That and the eye tends to ignore power drops, anyway. Unless they're bright green, of course.

I am looking for a way to make it as safe as possible or to find solid reasoning to refuse this kind of install altogether.

Usual method is to tape the flat 12/3 to the floor with 3" wide plastic tape, which somewhat protects it from abrasion, and to use 6/4 or 6/5 FCC-type to connect load centers. To me, this falls into the "qualified person" sort of thing- I wouldn't hesitate to do this for a week with factory-made flat extension cords that I inspected as I installed (and again as I removed). I would not make my own flat extensions, takes too much time. And I wouldn't recommend that somebody do this in their office and forget about it.
 

renosteinke

Senior Member
Location
NE Arkansas
There's nothing in the NEC that would prohibit such a product - it's just that no one has developed such a thing and submitted it for listing.

Apart from the testing of the cord, the connectors would need evaluation. Ordinary cord caps just are not designed for flat cords.

The closest product is what the NEC calls "Flat Conductor Cable." This is intended for a permanent instal, and has special junction boxes, etc.

Drop cords also tend to 'disappear' when you use white cable. Likewise, an "SJTO" cord is a lot skinnier than an "SO," and thus less obvious.
 

Hendrix

Senior Member
Location
New England
I am trying to purchase bulk quantities of flat 12-3 cable/cord to use for temporary connections similar to entertainment purposes. The only thing that I can find is pre-made flat extension cords. I would like to make custom lengths and terminate the ends myself. Anyone have any ideas? And is there anything wrong with running this cable under carpet for temporary power?
Have you considered UF? Its flat but you have to protect it.
 
Have you considered UF? Its flat but you have to protect it.

UF is a bad idea- it isn't flexible and the jacket isn't designed for abrasion. Most or all 12/3 flat extensions are type SPT and for extra-hard service usage. Oh, and I see at least one manufacturer makes 100' unit ("For use in accordance with the UL category for Trade show Equipment-Exhibition Display Units-Accessories").
 

Brunz

Member
Location
Harrisburg, PA
UF is a bad idea- it isn't flexible and the jacket isn't designed for abrasion. Most or all 12/3 flat extensions are type SPT and for extra-hard service usage. Oh, and I see at least one manufacturer makes 100' unit ("For use in accordance with the UL category for Trade show Equipment-Exhibition Display Units-Accessories").

I agree that UF will not work. We've tried to use it in the past, but the insulation splits and the cable itself is too difficult to roll up and store.


04-13-11 01:58 PMrenosteinke
There's nothing in the NEC that would prohibit such a product - it's just that no one has developed such a thing and submitted it for listing.

Apart from the testing of the cord, the connectors would need evaluation. Ordinary cord caps just are not designed for flat cords.

The closest product is what the NEC calls "Flat Conductor Cable." This is intended for a permanent instal, and has special junction boxes, etc.

Drop cords also tend to 'disappear' when you use white cable. Likewise, an "SJTO" cord is a lot skinnier than an "SO," and thus less obvious.


This explains why I am having such a hard time finding a vendor or manufacturer to purchase this raw cable from. The thought process behind buying bulk cable and installing cord caps was just to be able to make custom lengths as not all of the service runs we have to make are the same lenghth.
Thank you for all of your feedback, I will look into purchasing pre-made cords and taping them down before the carpet is laid. The real bummer is that it seems as the forklifts, ect smash the ends of our cords, we may not be able to replace them, thus making the rest of the cord useless.
 

iwire

Moderator
Staff member
Location
Massachusetts
I am aware of the hazards involved with running flexible cord especially in a permanent setting. This is strictly temporary.

The code section I posted applies equally to temporary installations as permanent.

You can run the cables on the floor but IMO you can not and should not run them 'under a rug' there are products to protect cables on floors.
 

fredk

New member
FLAT EXTENSION CORDS

FLAT EXTENSION CORDS

You probably are finding these 12/3 flat extension cords because they are not UL Listed. Flat cords up to 15' may be UL Listed (referred to as an air conditioner extension cord), but no longer than 15'. As explained to me by the engineer at Yellow Jacket, flat cords tend to twist and the outside conductors get stretched to accommodate the twisting and thereby reduce their diameter. This is why UL will not list flat 3-wire cords. Also, flat cords have less insulation. This company use to make them, but they are not UL Listed. Stay away from this in a commercial setting.
 
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