Hello, please consider and help me to solve my puzzle. All went well during first NO-load energizing of the 15kV/6kV 2,5MVA transformer via cable line of L=400m (3x150mm2 Alu, probably with inrush-current about 10*FLA, Sepam protection). However we got problem with the other loaded cable line supplied by the distant substation which is laid parallelly in the earth with this first cable about 200m along. The circuit breaker in this distant substation was tripped-off simultaneously with this 2,5MVA-trafo-energizing (by the protection unit VIP35 of Merlin Gerin, with settings Is=80A and Io=12A/0,6sec). The suspicion is towards this earth short-circuit protection because of lack of better proposal (the log of events from VIP is not accessible, we got the kick into the ass so the replay of the experiment is not possible to perform). Is this possible such an explanation and why?