Current transformer with split core 500-5A class 0.5 TO-500-5

Precise measurement of large currents in a compact design

The TO-500-5 current transformer is a professional solution for measuring and monitoring high-load electrical installations. Thanks to its split-core design, it allows for installation on existing conductors without the need to disconnect them, which significantly simplifies installation in existing systems.

Principle of operation and construction

The device operates on the principle of proportional transformation - the conductor with the measured current (500A) passes through the main opening with dimensions of 80×50mm, effectively creating a single primary winding turn. The secondary winding with a nominal current of 5A is connected via S1/S2 screw terminals to the measuring circuit of the monitoring device.

The ratio of currents in both windings remains constant and defines the transformation ratio N = IPn/ISn = 500/5 = 100. The measured secondary current allows determining the primary value according to the formula IPm = ISm × N.

Electrical parameters and safety

The model is characterized by an accuracy class of 0.5, ensuring high measurement precision for demanding industrial applications. The apparent power of 2.5 VA guarantees adequate performance while maintaining compact dimensions.

The device operates in a frequency range of 50-60Hz at a maximum operating voltage of 0.66kV AC. The insulation withstands a breakdown voltage of 3kV per minute, ensuring safe operation in industrial conditions.

The safety factor FS < 5 protects against the effects of overload, and the protection rating IP20 protects against accidental contact with live parts.

Operating conditions and mounting

The transformer maintains full functionality in temperatures from -15°C to +50°C, proving effective in both cold storage and hot industrial environments. It can be mounted vertically or horizontally on a distribution board.

It is recommended to connect the secondary circuit with a conductor of a minimum cross-section of 2.5mm² and to ground the S2 terminal for optimal measurement stability.

Compliance and standards

The product meets the requirements of the IEC 60044-1 standard, guaranteeing international compliance and safe operation in automation and power measurement systems.

The compact design with dimensions of 145×114×32mm and a weight of approximately 0.9kg facilitates installation in limited panel space while maintaining full measurement functionality for installations up to 500A.