Proudový transformátor CT 125/5 A průměr 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. It is designed for use with ammeters, energy meters, and protective devices.

Characteristics and Applications

The current transformer CT 125/5 A is a device that converts a primary current of 125 A into a secondary current of 5 A. This reduction allows safe connection to measurement and protective devices not designed to handle high currents. The bore diameter of 21 mm and aperture dimensions of 16×12.5 mm ensure compatibility with various types of conductors and busbars. Class accuracy 0.5 guarantees reliable measurements, which is especially critical in billing and control applications.

Primary applications of this transformer include:

• Current measurement: Precise monitoring of load in electrical circuits.
• Protection: Coordination with residual current devices and protective relays against overloads and short circuits.
• Energy recording: Measurement of electrical energy consumption in metering systems.
• Automation: Signaling when preset current thresholds are exceeded in control systems.

Construction and Parameters

The transformer’s construction is based on a ferromagnetic core that generates a magnetic field proportional to the current flowing through the primary conductor. The transformer features a screw-type connection for the secondary circuit, facilitating easy installation and connection to measurement devices. The overcurrent factor FS 5 indicates that the transformer can temporarily withstand currents significantly higher than nominal (up to 5 times) without damage or loss of accuracy—this is essential during motor startups or when powering other devices with high inrush currents. The rated secondary apparent power is 2 VA, with power consumption of only 2 W—minimizing energy losses. The device also holds a legal metrological certification, confirming compliance with applicable standards and regulations.

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