Article 590

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Temporary Installations 590.4 General Revised text clarifies that Type NM cable used for temporary feeder installations isn’t limited by building height, construction type, or concealment. (B) Feeders. Because of the concern for worker safety, open conductors are not permitted for temporary feeder installations. However, cable assemblies, hard-usage and extra-hard usage cords, and Type NM cable are permitted where the conductors are protected from overcurrent in accordance with their ampacities as required by 240.4. Figure 590-1 Type NM cables can be used in any building or structure, without any height limitation or limitation by building construction type as described in 334.12(2), and without having to be concealed within walls, floors, or ceilings as described in 334.10(3). Figure 590-2 Author’s Comment: The language in the 2002 NEC prohibited the use of Type NM cable for temporary installations in some building construction types over three floors.

Figure 590-1 (Click on image to enlarge) Figure 590-2 (Click on image to enlarge)