Open-core current transformers with compact dimensions for easy installation. This type of transformer is very easy to install and uninstall on compact panels where the reduced space makes it difficult to take current measurements. In addition, their open-core design means that they can take measurements without having to interrupt the electric supply. The primary current measurement range is from 100 A to 300 A using different secondary outputs (.../1A, .../5A or .../250mA) with a maximum admissible cable diameter of 24 mm.