Carlo Gavazzi Current Sensor Split-Core 1-Phase AC, Class 1, Input: 0-400A AC, Output: 4-20mA. The ROG400 is a split core AC TRMS current sensor able to measure a primary current (up to 400A) from a single phase power cable. The output signal is proportional to the measured input with a range from 4mA to 20mADC. The sensor has to be fixed directly around the main primary cable.