My iso trans 3600w auto is humming. Is this normal? Than if i measure between input output earth i measure connection. This should not be possible is it? Between in and out neatral not conection measured, also not between live in and out.
Now if i disconnect the land powercable, no connection between earth in and out is measured.
When i measure the earth in the plug from landpower cable, connected on shore, DISconnected on ship, is measured connection between ship and earth from cable, so shore earth.
Is this normal? Do i have a good protection against corrosion?