Phoenix Contact 2906282 A universal varistor-based plug-in lightning/surge arrester is designed specifically for single-phase power supply networks that utilize a two-conductor system consisting of the live line (L1) and the neutral and earth (N and PE). This device features common connections between these conductors, including an N connection to one conductor and a PE connection to the other. Additionally, this plug-in arrester is equipped with remote indication contacts that allow for easy monitoring and diagnosis of its performance.