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What's Wrong Here?

Jun 8, 2004 7:15 PM, By Joe Tedesco

This installation is sloppy and doesn’t meet the neat and workmanlike requirement of 110.12. In addition, the restrictions of permitted fill in the cable tray have been ignored (Art. 392) and many of the conductors are subject to physical damage.

Per the requirements of 392.3(B), “The wiring methods in Table 392.3(A) shall be permitted to be used in any industrial establishment under the conditions described in their respective articles. In industrial establishments only, where conditions of maintenance and supervision ensure that only qualified persons service the installed cable tray system, any of the cables in 392.3(B)(1) and (2) shall be permitted to be installed in ladder, ventilated trough, solid bottom, or ventilated channel cable trays.

“(1) Single Conductors. Single-conductor cables shall be permitted to be installed in accordance with the following:

“(a) Single-conductor cable shall be 1/0 AWG or larger and shall be of a type listed and marked on the surface for use in cable trays. Where 1/0 AWG through 4/0 AWG single-conductor cables are installed in ladder cable tray, the maximum allowable rung spacing for the ladder cable tray shall be 230 mm (9 in.).

“(b) Welding cables shall comply with the provisions of Article 630, Part IV.

“(c) Single conductors used as equipment grounding conductors shall be insulated, covered, or bare, and they shall be 4 AWG or larger.”