Fires in electrical circuits often occur due to short circuits, overloads, excessive contact resistance and other reasons that generate sparks or cause wires and cables to reach dangerously high temperatures.
The main causes of fires and explosions in electrical circuits are:
(1) Electrical circuits catch fire due to a short circuit. The instantaneous discharge of the short circuit generates considerable heat, which. can burn the insulation and melt the metal wire, causing a fire.
(2) Electrical circuits are overloaded. Generally, the maximum allowable conductor temperature is 65°C. In case of prolonged overload, the temperature of the conductors will exceed this allowable temperature, which will accelerate the temperature. aging and damage to conductor insulation and cause fires.
(3) The contact resistancet at the wire connection is too large, the wire joint is not firm, the contact is poor, overheating occurs, and even the wire joint melts, causing a fire.
The above content is compiled based on the problems encountered by students in actual work for reference. If you have any questions, please communicate and correct them in time.