How does the Earth Fault protection work in Micrologic 6.0 when Neutral CT is not connected.


23 January 2021

When the Neutral CT is not connected, the Earth Fault protection still operates in Micrologic 6.0 trip unit as it works on the principal of vectorial sum calculation of 3 phases.

In case of Earth Fault, the internal current sensor which makes the vectorial sum, detects the Earth Current and gives a tripping order according to Ig (Earth Fault Current) and tg (Tripping time for Earth Fault) settings.