Historically, the NEC has allowed cable trays, but has lacked specific guidelines for sizing conductors and using smaller conductors like PV wire and DG cable on rooftops. Cable tray installation on roof plays a crucial role in organizing and protecting electrical cables, particularly in commercial or industrial settings. Rooftop installations are often subjected to harsh environmental conditions, including extreme temperatures, high winds, and exposure to UV. In this installment of our Code Corner series, Ryan Mayfield focuses on the 2023 National Electrical Code (NEC) changes concerning cable trays, particularly section 690. 1) Use Cable Trays! The first and most obvious of these best practices is that you should always use cable trays. Commercial. Poorly installed cabling on flat roofs can be a major hazard – for both rooftop workers and for the cabling itself.
[PDF Version]