Some reasons for overheating of electrical equipment

The main function of electrical equipment is to transmit, distribute, and convert electrical energy, which is achieved through the flow of current. Many faults and accidents in electrical equipment are caused by overheating. Early detection and elimination of overheating can greatly reduce faults and accidents in the power system and improve power supply reliability.

1. Overload

The so-called overload refers to the current of electrical equipment or wires exceeding their rated value. After overload, the current increases, and over time, it can cause electrical equipment to overheat.

2. Short circuit

Short circuit is the most serious fault state of electrical equipment. Most fires in the power grid are caused by short circuits. After a short circuit, the current in the circuit increases several times or even tens of times that of normal, causing a sharp rise in temperature. If it reaches the ignition temperature of surrounding combustibles, it can trigger a fire.

3. Poor contact and poor heat dissipation

Poor contact mainly occurs at the conductor connection, such as loose fixed joint connection, poor welding, or surface contamination of the joint, which can increase insulation resistance and cause overheating of the joint. Removable electrical connectors may become loose due to vibration or heat, which can also cause overheating of the connectors. Various electrical equipment will have certain ventilation and heat dissipation devices during design and installation. If these facilities fail, it can also cause overheating of the circuit and equipment.

4. Leakage

After insulation damage to electrical circuits or equipment, leakage may occur under certain conditions, and the leakage current is generally not large, which cannot cause the circuit fuse to operate and is therefore not easily detected. When the leakage current is evenly distributed, the fire hazard is not significant; But when the leakage current is concentrated at a certain point, it may cause severe local heating and cause a fire.