What is the difference between Power Frequency Wet and Dry Withstand Voltages?

As the name suggested, one tested in dry atmospheric condition and the other under simulate wet condition.

Please review your applicable IEEE test code standards for general HV testing.

Std 4 ?

thanks Raymond Lee, but this is not the feedback I am expecting. Thanks.

All overhead insulators are tested dry condition and wet condition with 5 KV megger. In wet condition you have to spray water and take the reading. If there may be crack which is not visible then in this test you can get that fault.

Knowing the Power Frequency withstand voltage or BIL, how do u determine the dry AC withstand voltage and the wet AC withstand voltage for a 33kV and 11kV rated voltage. For say a transformer, an insulator, surge arrester etc.

I am really not interested in how the test is performed? but how to determine it and what they mean to a buyer if manufacturer says the dry withstand voltage is xxx and the wet withstand voltage is yyy. Thanks

For that you have to perform the Lab test means using HIPOT Test.