The recommended approach is to use a separate DC grounding electrode for PV arrays and frames, as this enhances protection against lightning and transient voltage. For lightning protection associated with grounding systems, refer to NFPA 780 and NEC 250. Surge protection devices (SPDs) installed inside the distribution box help protect photovoltaic systems from transient voltage surges caused by lightning. In many photovoltaic systems, inverter grounding shares the same grounding network as the distribution box and lightning protection system. This is especially concerning for large-scale C&I PV plants, where system interruptions can result in significant. The main common faults are as below. The lightning arrester is damp The main cause of moisture absorption in lightning arresters is poor sealing or the introduction of moisture during the assembly process. (PV grounding diagram for 120/240V split phase solar system).