1993 NEC Section 300-7 (b) states that “Raceways shall be provided with expansion joints where necessary to compensate for the thermal expansion or contraction. This subject. us-trations without notice. All illustrations, descriptions and technical information included in this document are provided as indications and can cable trays are equivalent. The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned. , is a welded wire-mesh cable management system made of high-strength steel wire. It is used to manage cables for light B manufactures its cable tray in a range of materials with a variety of finishes. The selection of material and finish is a function of the environment in wh tant in a wide range. Cable trays play a vital role in supporting electrical cables and wires in commercial, industrial, and utility installations.