AC Surge Protection Considerations *Image: 3Phase & 1Phase AC SPDs Lightning flashes from clouds to the lightning protection system, the PV structure or a nearby ground cause a local ground-potential rise with regard to distant ground references. Conductors spanning these distances expose equipment to significant voltages. The effects of ground-potential rises are primarily experienced at the point of connection between a grid-tied PV system and the utility at the service entrance—the point where the .
PV installations must be designed to provide full exposure to the sunlight and hence they are highly vulnerable to the effects of lightning. The capacity of a PV array is directly related to its exposed surface area, so the potential impact of lightning events increases with system size. Where lighting occurrences are frequent, unprotected PV systems can suffer repeated and significant damage to key components. This results in substantial repair and replacement costs, system .
Not only for string combiner box but anywhere as per standard practice, we select fuse/breaker size with the help of the below formula: Fuse/Breaker rating size = Current X 1.2 or 1.3 times Suppose we selected 280Wp module, as per datasheet Isc is 8.68Amps so Selected Fuse = 8.68Amps X 1.25 = 10.85Amps so selected fuse say 12Amps But in case of solar system design this formula many times fail to provide .