General
Enclosure diameter	52 mm
Load resistance	≤ 15 Ω

The C122 current transformer from Chauvin Arnoux is a current measuring device from the "C" series, specifically designed for measuring alternating currents in the range of 1 A to 1200 A AC. The device is suitable for use in industrial and office buildings, where precise current measurements on conductors up to 600 V CAT III are required. With an enclosure diameter of 52 mm, it can be used on most cables and conductors in commercial and industrial installations. The round shape of the jaw and the uniform winding of the coil ensure high measurement accuracy and minimal phase shift, which is crucial for accurate and reliable measurement results.

Applications
The C122 is designed for use in industrial and commercial environments where precise current measurements are required without shutting down the system. It is commonly used in electrical installations, maintenance of energy distribution systems, and monitoring of power consumption in office and production facilities. The safety class CAT III 600 V allows use on conductors that are normally subjected to high voltages, making it suitable for use in electrical distribution systems.

Functions and Equipment in Detail
The device features a patented support system and a pendulum hinge system that enables stepless, supported opening of the jaws. This facilitates handling and ensures secure alignment of the magnetic circuit with the cable to be measured. The output sockets are equipped with 4-mm-insulated plugs and include overvoltage protection to protect the connected measuring device from damage due to transient voltage surges. The output signals are available as alternating current, enabling direct connection to multimeters, wattmeters, recording devices, or oscilloscopes.

Technology Explained Simply
The C122 operates as a current transformer and converts the primary alternating current in the ratio 1000:5 into a proportional output signal. This ratio means that a current of 1000 A in the primary circuit generates an output signal of 5 A in the secondary circuit. Typical accuracy is ≤ 1 %, which is sufficient for precise measurements in demanding environments. The device's bandwidth ranges from 30 Hz to 10 kHz, allowing it to capture higher frequencies. The maximum continuous current load is 1000 A at frequencies up to 1 kHz, with load capacity decreasing proportionally at higher frequencies. Short-term loads up to 1200 A are possible for a maximum of 40 minutes, with a recommended pause of at least 20 minutes between measurements.

Compatibility and Accessories
The C122 is compatible with a wide range of measuring instruments, including multimeters, wattmeters, recording devices, and oscilloscopes, as it provides a standardized output signal. Suitable accessories available in the range include a set of 2 adapters BNC socket/4mm plug, enabling connection to devices with BNC connectors. These adapters extend the application possibilities of the C122, especially when used with oscilloscopes or data loggers.

Mounting and Installation
Installation is done by simply clamping the conductor to be measured with the jaws. The jaws open via the pendulum hinge system and patented support system, ensuring secure and precise positioning. The clamp is not permanently mounted but is applied to the cable as needed and removed after measurement. Operation requires no tools and is possible even with limited access to conductors.

Operational Advantages
The C122 offers high measurement accuracy and stability under varying environmental conditions. The minimal phase shift ensures accurate representation of the current waveform, which is important for analyzing power factor or harmonics. The robust construction with a housing made of self-extinguishing material (UL94 V0) and protection class IP40 (IEC 529) ensures long service life and safety. The ergonomic design with integrated finger grips and the pendulum hinge system facilitates handling, especially with frequent use.

Safety and Standards
The device complies with the standard IEC 61010 and is approved for use in safety class CAT III 600 V. This means it is designed for measurements on electrical systems that are normally subjected to voltages up to 600 V under normal operating conditions. The double insulation between primary and secondary circuits protects the user and the connected device from electrical hazards. The housing protection class IP40 protects against contact with moving parts and against ingress of solid foreign objects larger than 1 mm, but not against water or dust.

Scope of Delivery
The scope of delivery includes the current measuring clamp C122 and the instruction manual.

Operating Environments
The device can be operated at temperatures from -10 °C to +50 °C and is suitable for storage from -40 °C to +70 °C. The relative humidity during operation must not exceed 85 % RH, with permissible humidity decreasing linearly from 35 °C. The maximum operating altitude is 2000 m above sea level.

Dimensions and Weight
The dimensions of the device are 216 mm (length) × 111 mm (width) × 45 mm (height), and the weight is 550 g. The housing is dark gray, and the jaws are marked in red.

Accessories and Alternatives
To extend application possibilities, adapters are available that enable connection to devices with BNC connectors.