The City of Phoenix as adopted an Citywide Interpretation concerning New Solar PV Live Loads on Existing Building Roof Structures.

The sub-title is: Adding a new solar Photovoltaic (PV) panel system to an existing building's roof structure where the existing building is not undergoing a change of occupancy.

Basically an interpretation of the 2018 IEBC 303, 502.4, 503.3, 806.2 code. Designers of PV systems ahould review the Interpretation at:

https://www.phoenix.gov/pddsite/Documents/TRT/dsd_trt_pdf_00844.pdf

There is also Interpretation covering Solar Panel Connections:

https://www.phoenix.gov/pddsite/Documents/TRT/dsd_trt_pdf_00702.pdf