Current transformer CT 125/5 A, diameter 21 / 16x12.5 412104

Current transformers are a key component in measurement systems, enabling safe and precise monitoring of high-current values. The CT 125/5 A model stands out for its compact design and high accuracy, making it indispensable in both industrial and commercial installations. Designed for use with ammeters, energy meters, and protective relays.

Characteristics and Applications

The current transformer CT 125/5 A is designed to convert a primary current of 125 A into a secondary current of 5 A. This reduction allows safe connection to measurement and protective devices that are not rated for direct handling of high currents. The 21 mm bore diameter and aperture dimensions of 16x12.5 mm ensure compatibility with various cable and busbar types. Class accuracy 0.5 guarantees reliable measurements, which is especially critical in billing and control applications.

Designed for applications including:

• Current measurement: Precise monitoring of load in electrical circuits.
• Protection: Integration with residual current devices and protective relays against overloads and short circuits.
• Energy metering: Accurate recording of electrical energy consumption in metering systems.
• Automation: Signal generation for current threshold exceedances in control systems.

Construction and Specifications

The transformer is built around a ferromagnetic core that generates a magnetic field proportional to the primary current flowing through the conductor. The device features a screw-type connection for the secondary circuit, facilitating easy installation and connection to measurement instruments. The saturation factor (FS) of 5 indicates that the transformer can temporarily withstand currents up to five times the nominal value without damage or loss of accuracy—essential during motor starting or other high-inrush applications. The rated secondary apparent power is 2 VA, with power consumption仅为 2 W—minimizing energy losses. The device is certified with legal verification, confirming compliance with applicable metrological standards and regulations.

Additionally, the 0.5 accuracy class ensures a measurement error not exceeding 0.5% of the nominal value, guaranteeing high measurement precision. The transformer is designed with user safety in mind—it includes protection against accidental contact, significantly reducing the risk of electric shock during operation and maintenance.