As a Type 2 Acti9 surge arrester, this device is built for the distribution board -- the standard, most common install point in a low-voltage system. Type 2 is the minimum level of surge protection recommended for any electrical installation, lightning rod or not -- it intercepts the induced surges from nearby lightning strikes and the switching transients that ordinary grid and equipment operation generate. Built for a three-phase-plus-neutral circuit, it holds a 350V Uc rating (maximum continuous operating voltage) -- high enough above everyday supply voltage to avoid nuisance tripping, low enough to still react promptly when a surge hits. Its 15kA nominal discharge current (In) is the standardized rating for repeated surge events, backed by a 40kA maximum discharge capacity for a single severe event. Its voltage protection level (Up) stays under 1.
