NEMA VE 1 – This standard specifies the manufacturing requirements for metal cable trays (such as; channel cable tray, ladder cable tray, single-rail cable tray, wire mesh cable tray, solid bottom or nonventillated cable tray and trough or ventilated cable tray) and associated. NEMA VE 1 – This standard specifies the manufacturing requirements for metal cable trays (such as; channel cable tray, ladder cable tray, single-rail cable tray, wire mesh cable tray, solid bottom or nonventillated cable tray and trough or ventilated cable tray) and associated. ect the minimum bend ra-dius for cables as they exit the bottom of the cable tray. A rung spacing of 6 to 9 inches (150 to 230 mm) is preferable when the cable tray cont d for instrumentation and control applications that require additional protec eferred to support and protect numerous small. It is the first joint effort of NEMA and CSA International to put in one place standards for metal trays per both NEMA and CSA methods. Addresses shipping, handling, storing, and installation of metal cable tray systems. The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned in this technical guide only apply to our own cable management ranges and cannot under any circumstances be transposed to si osure, overheating or. All rights, including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention for the Protection of Literary and Artistic Works, and the International and Pan American copyright conventions. The information in this publication was considered. NEC Article 392 sets the rules for cable tray systems, from permitted wiring methods and installation requirements to cable fill and ampacity adjustments. The Core Standards: Overview Key Insight: BS EN 61537 is technically identical to IEC 61537 but includes UK-specific guidance and deviations. Head-to-Head Comparison: Critical.