Code Change Summary: New code language requires temporary branch circuit and feeders to be kept off the ground.

For temporary installations, such as jobsite power, article 590 allows wiring methods and materials that would never pass inspection if installed in the same manner as a permanent wiring method.

A building of type 1 (noncombustible) construction for example, is not permitted to be wired using exposed nonmetallic sheathed cable (see 334.10), but for temporary jobsite power during construction, nonmetallic sheathed cables are permitted to be strung throughout the building, or installed above a suspended ceiling. Open splices without a junction box are also permitted. Because the cables are tucked up and out of the way and considered temporary, they are permitted to be used until the building is far enough along to get permanent power.

In the 2014 NEC^®, additional text was added in 590.4(J) to require temporary cable assemblies, flexible cords and cables installed as branch circuits or feeders to be kept up off of the ground. It’s one thing to have the substandard wiring methods tucked up and out of the way but it’s another thing altogether to have them laying on the ground, exposed to wet conditions before the roof is dried in, while construction workers constantly walk on them. Before this code change, there was nothing in article 590 specifically prohibiting this.

Below is a preview of the NEC^®.  See the actual NEC^® text at NFPA.ORG for the complete code section. Once there, click on the “free access” tab and select the applicable year of NFPA 70 (National Electrical code).