I think your helmet is on too tight. I'm entitled to a smartass remark if you're f'ing wrong.
Electric dryers and ranges require a 120/240V circuit, not a 240V circuit. Typical cubicles do not require 3 phase power. Some are wired with 3 120V circuits sharing a neutral...which would be a MWBC.
Thanks Ultrafault, I enjoyed your comments.A good way for you to think of phases abyss is to think of your wires as points and the connections between them as the phase.
Draw two dots (Wires) then draw a line between them. That is one phase. Then add a third dot and connect them as a triangle. Now you have 3 lines thus 3 phases. As you see two wires create one phase it cannot be different. For two phases you must then need 4 wires. If you ever head to Pennsylvania you will see that is true.
Remember there is no voltage In a single wire only between wires and points.