a few weekends ago i had to rewire a 220v welder from a 3 prong dryer plug, to a 4 prong. at lowe's i kept asking if the 4 prong plug is 3 phase wiring, the answer every time was 'whats 3 phase wiring?". i found a diagram for rewiring a dryer for a 4 prong and it worked fine for the welder, so i didnt worry about it. but now im curious to know if the 4 prong plug was connected to 3 phase wiring. is 3 phase a common thing in residential areas? if not, i dont see the purpose for an extra contact in the plug.
(p.s. anyone have an oscilloscope they dont need? ill pay shipping!!) haha!
(p.s. anyone have an oscilloscope they dont need? ill pay shipping!!) haha!