Using zinc oxide varistor and discharger combination to maximize discharge capacity, wietap surge arresters for control cabinet main power supply protection (IEC Class II, Cat B) include modules rated for 150, 275, 320, 385, 440, and 600 V. Line also includes modules for sub-distribution (IEC Class III, Cat A) with ratings of 30 and 150 V. Also available, surge protection modules for PV systems come in 600 and 1,000 Vdc versions for grounded and ungrounded systems.