What Is A Split Core CT?

 A split core current transformer, often called a split core CT, is an electrical device used to measure alternating current in a conductor without disconnecting the circuit. It has a core that can be opened and clamped around a cable or busbar, allowing installation without power interruption.

One main feature of a split core CT is its convenient installation. Users do not need to cut cables or shut down the power supply during setup. This reduces downtime and improves safety, especially in existing power systems. Another advantage is electrical isolation, which separates high‑voltage primary circuits from low‑voltage secondary circuits. This design protects measuring instruments and workers from electric hazards. Split core CTs also offer stable accuracy and are available in different precision classes to support monitoring, metering, and protection applications. They are lightweight and compact, making them suitable for use in narrow spaces such as distribution boxes and control cabinets.

Split core CTs are widely used in many fields. They are commonly applied in power distribution systems, low‑voltage switchgears, and energy management systems. They work with energy meters, power monitors, data loggers, and industrial control equipment. They are also widely used in renovation projects where traditional closed CTs are difficult to install. In addition, they appear in motor control, building automation, and renewable energy systems including solar and wind power generation.

There are several types of split core CTs based on structure and application. Clamp‑on split core CTs are the most common type, suitable for regular round cables. Busbar types are designed for flat and wide conductors. Miniature split core CTs are used in small current measurement and compact equipment. High‑accuracy models support billing‑level energy metering. Flexible types, such as Rogowski coils, adapt to large or irregularly arranged conductors where standard split cores cannot fit.