Article 398 Open Wiring on Insulators

I. General

This type of wiring is exposed with a single insulated conductor using an insulator (knob, cleat, tube, or flexible tubing) for protection and support.

II. Installation

This type of wiring can be used only where the nominal voltage does not exceed 600 V, in industrial or agricultural structures, both indoors and outdoors, both wet and dry locations, for services, and where corrosive vapors are present.

Cannot be used if concealed by the building structure.

III. Construction Specifications