Varistor surge arrester with spark gap NPE 12.5kA -BY2-B+C/3+NPE 3213031

Modular, varistor surge arresters for protection of LV power supply installations in small buildings, single-family houses, apartments and other compact buildings. They provide sufficient protection both against the effects of overvoltages caused by lightning, as well as induced or switching overvoltages. Mounted in a cable connector or main switchgear. For TT and IT networks, a combination of BY1-B/3 arrester and NPE spark gap is used. The control windows indicate the state of correct operation (green color) and the state of varistor damage (red color). In case of damage to the varistor, the arrester insert must be replaced immediately. The arresters are also available equipped with an acoustic-contact damage signaling module and a signaling contact. Varistor limiters must be subject to systematic control (after each storm and after the end of the storm season).