Code Corner: 2023 NEC Article 690.31(C) and (C)(2) Cable Tray

In this installment of our Code Corner series, Ryan Mayfield focuses on the 2023 National Electrical Code (NEC) changes concerning cable trays, particularly section 690.31 (C).

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. The 2023 update provides clarification and formalizes the use of small conductors in cable trays.

The updated section 690.31(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 bundling of conductors in some instances, and also gives better guidance on calculating ampacities and correction factors for different installation methods. 

Check it out in more detail here:

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