The main objective of the electrical installation protection system is to limit overvoltages to values that are acceptable for the equipment.
The electrical installation protection system consists of:
1.one or more SPDs depending on the building configuration;
2.the equipotential bonding: metallic mesh of exposed conductive parts.
The system for protecting a building against the effects of lightning must include:
1.protection of structures against direct lightning strokes;
2.protection of electrical installations against direct and indirect lightning strokes.
Common mode SPD between phase and PE or phase and PEN is installed whatever type of system earthing arrangement.
Another SPD architecture is therefore used
The SPD chiefly consists of: 1) one or more nonlinear components: the live part (varistor, gas discharge tube, etc.); 2) a thermal protective device (internal disconnector) which protects it from thermal runaway at end of life (SPD with varistor); 3) an indicator which indicates end of life of the SPD; Some SPDs allow remote reporting of this indication; 4) an external SCPD which provides protection against short circuits (this device can be integrated into the SPD).
