The characteristics of the equipment are chosen in such a way that it can withstand the mechanical and thermal effects produced by any overcurrent without harm to persons and, where appropriate, without impairing its safety functions, for the time necessary for the operation of the devices intended to interrupt this overcurrent.
The switchgear and controlgear used for connection, isolation, control and protection are chosen and installed in such a way as to be able to perform these functions.
Conductors in fixed conduits are protected against overcurrents.
Equipment containing flammable liquid dielectrics and dry-type transformers are installed and protected in such a way as to prevent the risk of fire.