How is "thermal overload" defined in electrical terms?

Thermal overload in electrical terms refers to a condition where excessive current flow generates a buildup of heat beyond the equipment's rated capacity. This phenomenon occurs when an electrical device or conductor is subjected to higher-than-normal currents for an extended period, causing the device to reach temperatures that can lead to insulation failure, mechanical stress, or even complete failure of the electrical components.

In many electrical systems, thermal overload protection devices, such as circuit breakers and fuses, are installed to prevent damage caused by excessive heat. These devices are designed to open the circuit when the current exceeds a predetermined safe limit, effectively mitigating the risk of heat-related failures.

Recognizing thermal overload is crucial for maintaining the safe operation of electrical systems and ensuring longevity and reliability. This understanding is essential for technicians in their assessments and repairs of electrical equipment to prevent hazardous situations.