What is the primary role of a current transformer (CT)?

The primary role of a current transformer (CT) is to step down high current levels to a lower, manageable level that can be safely used for measurement and monitoring purposes. This allows for accurate measurement of electrical current in high-power systems without needing direct access to the high currents themselves, which can be dangerous and impractical to measure directly.

CTs are essential in the operation of protective relays and monitoring systems in electrical substations and industrial installations. By transforming high currents to lower levels, CTs enable instruments and devices to record and display the current values safely and effectively.

This function distinguishes them from transformers designed to step down voltage levels or those intended to increase current levels for transmission, which are not the primary use of a CT. Additionally, measuring power factor, while an important concept in electrical engineering, does not represent the main function of a current transformer. Current transformers are specifically focused on current measurement by providing a reduced current output that correlates to the primary current input, allowing for safe and accurate monitoring.