Txsparky:
You bring up a question regarding power to a pitching machine that I have never been able to resolve in my mind. At our local ballpark, the receptacle (similar to the one you show here) is wired to a 12/3 SO cable (and hides in a "water meter box" buried near the mound (no plumbing inside, just electric). When not in use, their MO is to wrap plastic around the receptacle, stuff the whole affair in the meter box, and turn off the circuit...sometimes (an ordinary 15a non-GFCI breaker). Naturally this meter box fills up with water, dirt, grass clippings, etc. It's a horrible setup. How is something like this accomplished in a professional, code-compliant manner, beside using extension cords (trip hazard) or a battery-powered device?
Mike (mamills)