I had to wire in the laser cutter at work. They said the phase direction mattered, and that it had to be clockwise, and it had to be known before attempting to power anything on.
I had no meter, no electricians or electrical techs I knew had a meter (aside from ones used to measure it for motors from back EMF) and I couldn't even find a clear definition of what was clockwise and what was counterclockwise if I were to use my scope.
In the end I set the E-stop circuit to lock out contactors and manually poked the contactor in for a hydraulic pump on the shuttle table. I was able to get that spinning the correct direction and then the whole machine worked.
It would be cool if there was some standard for phase orientation.