A Protection CT is designed to monitor current and activate protection devices (like relays, breakers) during fault conditions (overcurrent, short circuit).Used in low voltage systems (typically ≤1000V), it steps down high fault currents into measurable signals for protective relays to trip breakers fast.Unlike metering CTs, which prioritize accuracy under normal current, protection CTs are built to stay accurate even during very high fault currents (think 10–20x rated load!).