In addition to the insulation error, another fire risk remains that is not neglected because it is frequent, which is non-separable and incapable of melting? What is meant by poor contact in the fuse and the differential breaker as well as for the connection. Every time a bad contact (dilute the oxidation of the material) leads to heat when the current passes, weak at the beginning of time and more than that is important, the connection of the circuit breakers and sockets are always the object of experiment because the result is poor contact, followed by heating, which means fire.