Dry-Type Transformer Insulation Reading Megohms

Good morning everyone, I am doing insulation resistance on a dry type xfmr and I am reading Meg ohms. There is no LA attached the transformer is in a humid area

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If it was energized before its probably fine. Dry it out, heat it up, retest. Whats the PI/DAR? Winding specific?


The pi was 1.13 and the DAR was 1.10. I am not 100 :100: positive what you mean by the Winding specific?

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Pretty low PI. Winding specific as in is it the HV or LV winding to ground that has low results, or between HV/LV, or all 3?

There’s lots of good reading on Megger’s site about insulation resistance testing

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