Clarify TIG Polarity....

[BillC]

My old welder was physically switched from AC - DC - DC reverse. With this 255 EXT;DC TIG, the torch is negative with positive ground - and with AC TIG, the torch goes to positive - with negative ground. Correct? But if you were only welding with AC TIG - why would it matter if the torch was hooked to negative? High frequency arc start?

I used to be concerned about asking dumb questions - I've gotten too old to care any more! And memory - OK but fleeting.

Thanks!