What does a branch-circuit overcurrent device primarily protect?

The primary function of a branch-circuit overcurrent device is to protect wiring from overloads. When the current flowing through a circuit exceeds the safe carrying capacity of the wiring, the overcurrent device—such as a circuit breaker or fuse—trips or blows to interrupt the current flow. This action prevents excessive heat from building up in the wires, which could lead to insulation failure, potentially causing fires or damage to the electrical system.

While there may be secondary benefits to human safety and equipment protection, the primary purpose is specifically aimed at safeguarding the wiring infrastructure from conditions that could lead to overheating due to excessive current. Other responses focus on different aspects of electrical safety and equipment operation but do not directly address the function of overcurrent devices in terms of preserving the integrity of electrical wiring.