Good day.
I came across a fault yesterday afternoon, its a 22kv 50kva pole mounted transformer with a down running earth from the transformer tank(HV side) into its own crow foot earth and on the LV side it has a down running earth from the LV bushing to its own crow foot so on the transformer it self the HV and LV earth is seperated. Now the fault that occurred is that the HV earth at the bottom of the structure was cut off and when you test voltage between the piece that runs down from the transformer and actual earth it measures 670V and the metal meter box is attached to the pole and made contact with the earth which caused it to be alive. I would understand if it happened on the LV side but on the HV? the fault is sorted out but i would like to know the reason that would cause this voltage on the HV earth.
Thanks