Strujni transformator CT 125/5 A prečnik 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 with its compact design and high accuracy, making it indispensable in both industrial and commercial installations. It is designed to work with ammeters, energy meters, and protective circuits.

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 that are not designed to operate with high currents. The bore diameter of 21 mm and hole dimensions of 16x12.5 mm ensure compatibility with various types of conductors and busbars. Class accuracy 0.5 guarantees reliable measurements, which is especially important in billing and control applications.

Primary applications of this transformer include:

• Current measurement: Precise monitoring of load in electrical circuits.
• Protection: Cooperation with residual current devices and protective relays against overloads and short circuits.
• Energy recording: Measurement of electrical energy consumption in metering systems.
• Automation: Signaling current threshold exceedances 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 simple 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 — which is critical during motor startups or when powering other devices with high inrush currents. The rated secondary apparent power is 2 VA, and power consumption is 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 of 0.5 means a measurement error not exceeding 0.5% of the nominal value, ensuring high measurement precision. The transformer has been designed with user safety in mind — it features protection against accidental contact, minimizing the risk of electric shock during operation and maintenance.