31 (C) now aligns with the Code's broader language (like Article 392), allowing these smaller conductors and detailing how to calculate ampacities, the number of conductors permissible in cable trays, how to size cable trays correctly by width, layering or. The updated section 690. Addresses shipping, handling, storing, and installation of metal cable tray systems. Information on maintenance and system modification is also. The following pages address the 2014 National Electrical Code® requirements for cable tray systems as well as design solutions from practical experience. The information has been organized for use as a reference guide for both those unfamiliar and those experienced with cable tray. Nearly every. Cable tray systems have become an essential component in the infrastructure of modern commercial buildings, smart offices, data centers, and various industrial facilities. Cable tray is the preferred wiring method for industrial facilities, data centers, and large commercial buildings where routing dozens or. In the 2023 NEC ®, language was added in Article 690 to provide additional details for single-conductor PV wire smaller than 1/0 AWG installed in cable trays. 31 (C) (2) has allowed the use of PV or distributed generation (DG) cable in cable trays for PV installations but until this.