I'll weigh in here, there are plenty of tools that are both 110-120/220-240, so consider that split plugs give you the option of a simple plug change when you find that welder/plasma cutter isn't up to snuff on the low voltage set-up. Also I've used plenty of welders that just weren't performing with the 14 gauge/15A power, however they seem like a new machine on a 20A circuit with 12 gauge wire. Chop saws, bigger grinders [are included with the power requirements] as well as the welders-plasma's will run cooler and with more output with a bigger power supply. And to the 110-120/220-240 controversy I've personally seen many different tools/appliances stating 110V, 115V, 120V & 220V, 230V and 240V 115/230 V as the median and then the other Voltages are with-in a total 10% variance. I guess this is dependant on your age and vintage of the equiment you've used! Harry