In which scenarios are overloads that cause fires least likely to occur?

The scenario in which overloads that cause fires are least likely to occur is in properly sized circuits with operating overcurrent protection. Properly sized circuits ensure that the wiring can handle the expected electrical load without becoming overheated. Moreover, with effective overcurrent protection—like circuit breakers or fuses—any excess current that surpasses the safe limit will trigger the protective device, cutting off the electrical supply to prevent overheating and potential fire hazards.

When circuits are appropriately designed and equipped with functional protection devices, they significantly reduce the risks associated with overloads. This combination creates a safer electrical system capable of managing overload situations without leading to fire hazards.