What is the role of an overcurrent protection device (OCPD)?

• A. To regulate voltage
• B. To interrupt current flow to prevent overheating, fires, and equipment damage
• C. To filter power
• D. To indicate energy usage

Answer: (B)

An overcurrent protection device is designed to stop electrical current when it becomes higher than what the wiring and equipment can safely carry. By interrupting the circuit, it prevents the conductors from overheating, which could damage insulation, start a fire, or harm equipment. In normal conditions the device remains closed, but when a fault occurs—such as an overload or a short circuit—it trips or opens to isolate the circuit. Fuses physically melt open when current is too high, while circuit breakers trip and can be reset. This function is distinct from regulating voltage, filtering power, or indicating energy usage, which are handled by other devices.