For a current transformer, what it means if both insulation resistance and tan Delta are being reduced over a period. e.g. tan Delta reduced by 40% while insulation resistance reduced by 10 times
I have one HV 3 phase star ungrounded induction motor. Sometimes there is a short duration of 5 milliseconds high magnitude currents recorded at its neutral side. The frequency of occurrence is random, sometimes even few days. How can a fault be of such type? Please suggest.
