General
Enclosure diameter	20 mm

The MN39 current transformer from Chauvin Arnoux is a precise measuring instrument for capturing alternating currents in the range of 0.1 A to 240 A. It belongs to the MN series and is specifically designed for use in industrial and commercial installations, where accurate current measurement is required at tight or hard-to-reach locations. The device enables measurement of small to medium alternating currents and is approved for installations up to safety category CAT III 600 V and CAT IV 300 V, ensuring safe application in electrical installations.

Applications
The MN39 is particularly suitable for precise current measurements in industrial and office installations, where high resolution and accuracy are required. It is frequently used in the maintenance, servicing, and diagnosis of electrical systems to monitor the current consumption of individual circuits or devices. The compact design with a clamping diameter of 20 mm makes it ideal for use on tight cable bundles or in enclosures, where other current clamps would not fit due to size constraints.

Functions and Equipment in Detail
The current transformer features two measurement ranges: 0.1 A to 24 A and 0.5 A to 240 A. These separate ranges ensure improved resolution and accuracy, especially at low current values. The typical accuracy is ≤ 1 %, ensuring reliable and consistent measurement. The device provides an alternating voltage signal as output, transmitted via a permanently attached cable with a 4-mm-insulated plug. This plug ensures a secure and interference-free connection to measuring instruments such as multimeters or power analysers.

Technology Explained Simply
The MN39 operates on the principle of a current transformer: it detects the magnetic flux generated by the current flowing through a conductor and converts it into a proportional voltage signal. The turns ratio is 1 A/100 mV for the lower range (0.1–24 A) and 1 A/10 mV for the upper range (0.5–240 A). These values enable precise scaling of the output signal, ensuring compatibility with various measuring instruments. The safety standard IEC 61010 ensures that the device is suitable for use in electrical installations with the specified categories.

Compatibility and Accessories
The MN39 is designed for use with multimeters and power analysers that have a corresponding input for alternating voltage signals. The connection is made via the permanently mounted 4-mm plug, which provides a mechanically stable and electrically secure connection.

Mounting and Installation
Installation is carried out by simply clamping the conductor to be measured with the jaw. The ergonomic design of the device allows for safe handling, even in confined spaces. No tools or additional mounting effort are required. Measurement is contactless, ensuring the electrical safety of the operator.

Operational Advantages
The MN39 offers high measurement accuracy and reliability for capturing alternating currents. The two measurement ranges enable optimal resolution depending on the application. The robust construction and secure cable output ensure a long service life and seamless integration into existing measurement systems. Compliance with safety standards IEC 61010, as well as approval for CAT III 600 V and CAT IV 300 V, makes the device suitable for use in professional environments.

Scope of Delivery
The scope of delivery includes the MN39 current transformer and the operating instructions.