NEC Temporary Power

[mikedavis]

I have a question concerning the use of power cables for temporary power situations in an industrial facility. From my research the NEC does not allow for the extension of insulated power cables, in free air, attached to structures, or on the ground for temporary power requirements. Yet, I see this done in many different applications ( carnivals, concerts, exhibits, etc). Am I interpreting the code incorrectly ( missing an FPN, or exception). Does someone know how unprotected cables are allowed to be extended without wireways or conduit for temporary power.

Thanks,
Mike Davis

 

[don_resqcapt19]

Mike,
Have you looked at 590.4?

 

[Hutch708]

Temp. Installations - 2008 NEC Section 590.4 -
Allows cords or cables that meet Table 400.4 for hard or extra hard usage as feeders and branch curciuts.


Art. 525 also allows this for portable wiring for Carnivals and fairs

 

[cowboyjwc]

The problem with "temporary" in places other than fairs and carnivals and construction purposes and what not, is that it tends to become "permanent".

I tell guys, that use that word, all the time that electricity doesn't know it's only temporary.

 

[mikedavis]

NEC Temp Power

NEC Temp Power

Thanks folks, good information. In reviewing Article 590.4(C) I found the reference back to 590.2(A) which lead me to 590.2(B). I think I can use the language stated in 590.2(B) as a reasonable justification. This will give an Engineer in our group the opportunity to review the current or proposed installation and make sure that all reasonable precautions are taken to protect the cables from damage.

I agree that many temporary installations have a longer life than what would normally be considered temporary and that is why I brought up this concern to the experts here.

Thanks,
Mike

 

[Rockyd]

Temporary show power is a whole seperate world, in, and of itself. See some of the gear -

Gear is next to bullet proof, and is a major money game.

 

[tom baker]

Yet, I see this done in many different applications ( carnivals, concerts, exhibits, etc).
Mike Davis

These are all applications that have NEC articles. The articles are in chapter 5 so they can modify the rules in chapter 1-4, see section 90.3

 

[eric9822]

I agree that many temporary installations have a longer life than what would normally be considered temporary

This is a very common problem. We used to have "temporary" installations that seemed to last for many years. Now we tag them when they are put in; with a very bright orange tag. The tag is marked with the installer, the date of install, and when it is being removed. It has really helped us keep temporary from becoming permanent.