What is the function of the "trip coil" in an oil switch?

The trip coil in an oil switch serves a crucial role in ensuring the reliability and safety of power systems. Specifically, it is designed to automatically open the Oil Circuit Recloser (OCR) when it detects a high current situation. This function is essential for protecting the electrical system from damage that could occur due to overloads or faults. By opening the circuit under these high current conditions, the trip coil acts to prevent equipment failures, maintain system integrity, and performance.

The automatic operation of the trip coil is vital because it responds swiftly to extreme conditions, ensuring that the circuit is interrupted without requiring manual intervention. This automatic protection feature makes it an integral part of the overall safety mechanisms in electrical distribution systems.

The other options do not accurately describe the function of the trip coil. For instance, converting AC to DC pertains more to rectifiers rather than to trip coils in circuit protection devices. Measuring current flow is the function of protective relays or ammeters, not trip coils. Maintaining system pressure is typically associated with hydraulic or pneumatic systems, irrelevant to the trip coil's function in electrical protection. Thus, the correct identification of the trip coil's purpose reflects its critical function in enhancing safety and operational reliability in electrical systems.