Surge protection is a device that protects against transient overvoltages by limiting the frequency and duration of the subsequent current. These devices are also known as lightning arresters, surge protectors or varistors. Surge arresters protect equipment connected to the mains and are also an essential part of the protection of solar installations.
T1/T2 (B + C) surge protectors are designed to discharge high surge currents with a waveform of 10/350 μs that occur as a result of lightning strikes in three-phase and single-phase power supply networks (overhead lines) and/or overvoltages due to switching in the circuit (with a waveform of 8/20 μs). They are manufactured as compact units. Surge protection devices including protection units type 1 and 2 (T1/T2) are to be installed after the first short-circuit protection device, directly behind the electricity meter (in the main electricity distribution board).