A Three-Phase Current Transformer is designed to measure current in all three phases of an electrical system simultaneously. Its core principle remains electromagnetic induction. It typically consists of three separate transformer units, each with its own magnetic core and secondary winding, housed in a single compact enclosure. Each unit independently measures the current in one of the three phase conductors (L1, L2, L3). The magnetic field from each primary conductor induces a proportional, isolated, and reduced current in its respective secondary winding, providing accurate current signals for all three phases.
Product Features
1. Compact and Integrated Design: It combines three measurement units into one physical device, saving significant space in switchgear, control panels, and meter cabinets compared to installing three single-phase CTs.
2. Balanced Performance: The three transformer cores are manufactured together, ensuring nearly identical magnetic properties and transformation ratios. This guarantees consistent accuracy and phase balance across all three phases, which is crucial for protective relaying and precise metering.
3. Simplified Installation and Wiring: Using a single three-phase CT drastically reduces the number of components to mount and terminals to wire. This streamlines installation, minimizes potential connection errors, and lowers overall labor costs.
Common Applications
Its primary use is in three-phase power systems for:
1. Three-Phase Energy Metering in industrial, commercial, and utility applications.
2. Motor Protection and Control, monitoring load current to prevent overload damage.
3. Protective Relaying in electrical distribution boards and substations for functions like overcurrent and earth fault protection.
