what does polarity do

by Michael Timm
(Stillman Valley, IL)

On my Millermatic 115 you can reverse the polarity what is this feature used for

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bare wire mig requires dcep (reverse polarity) but some flux core wires require dcen ( straight polarity). you can look up the maker of the flux core wire and find a data sheet that lists the correct polarity....its a big deal too.

flux core that is designed to weld on dcen will run like crap on the wrong polarity