Nearly every week, I get calls and e-mails from inspectors, plan reviewers, photovoltaic (PV) professionals, engineers, and electricians asking about areas of PV system installation that are not clearly addressed in the National Electrical Code (NEC).

New and exciting improvements in the photovoltaic (PV) modules and PV systems are occurring each day.

Following a rooftop fire in a PV system, an AHJ was requested by the building department to inspect the damaged area and assist in the investigation of the cause of the fire.

Continuing education is critical. It will be mandatory to use all available communication devices and advanced tools at our disposal to effectively plan, review, and inspect the current and next generation of PV systems.

Codes, standards, equipment, and the organizations certifying that equipment meets a particular standard are continually changing. The harmonization of U.S. standards with international standards—while potentially reducing costs in the international arena—may complicate the application of these standards as they are adopted.

Before we get into the details of conductors, currents, and circuit protection on the AC side of the PV system, let’s step back and try to get a bigger picture of where are some of the dangers or hazards that need to be considered.

From an electrician’s, PV installer’s, or electrical inspector’s point of view, the currents start at the PV module—at least for the dc solar part of the system.

PV systems, small and large, residential, commercial, and utility-scale are becoming more complex every year and with every Code cycle.