Current transformer (CT)

About Current transformer (CT)

A Current Transformer (CT) is an essential instrument transformer used in electrical power systems for measurement and protection purposes. It is designed to step down high primary current to a lower, standardized secondary current (typically 1 A or 5 A) suitable for metering instruments, relays, and control equipment. CTs ensure accurate current measurement while providing electrical isolation between high-voltage circuits and low-voltage control systems, enhancing safety and reliability.

Current transformers are available in various types such as indoor and outdoor, oil-filled, resin cast, and gas-insulated designs to suit different voltage levels and installation requirements. They can be configured with metering cores for precise energy measurement and protection cores for fault detection and system protection. Designed with high-quality core materials and advanced insulation systems, CTs offer excellent accuracy, thermal stability, and long service life.

These transformers comply with international standards such as IEC 61869 and are capable of withstanding short-circuit currents and harsh environmental conditions. Widely used in substations, switchyards, industrial plants, and power distribution networks, current transformers play a critical role in monitoring, protection, and efficient operation of electrical systems.