...current. therefore, the first three channels remain for the overcurrent protections; for autotransformer/busbar/generator/reactor/motor applications, the first three (1st – 3rd) channels of ct+/5116 current module can detect the peaks of the differential currents, so the module can be only used for high impedance differential protection. more technical details can be found on the related product page:  https://www.protecta.hu/protecta_products/smartline/s24/variant-7