●●● Current transformers (CTs) reduce high primary currents to safe, proportional secondary currents (typically 1A or 5A) for measurement

 ●●● Current transformers (CTs) reduce high primary currents to safe, proportional secondary currents (typically 1A or 5A) for measurement, operating near a short-circuit state with a closed secondary circuit, providing electrical isolation, and characterized by their transformation ratio, accuracy class, burden (VA), and the critical need to never open-circuit the secondary winding. They use electromagnetic induction, stepping down current via a core with few primary turns and many secondary turns, enabling accurate monitoring and protection.