240v AC check pump surge

[e67]

If I want to check the max amps when my Franklin submersible 1 hp pump starts , 100 ft well and another 100 ft wire to panel.... I should check 1 hot wire at a time, no?
Should I do it at the well(easier) or at the control box inside..?

 

[Hedges]

Somewhere it is fed by 240V L1 and L2. Either one is sufficient, anywhere. Even back at circuit breaker.
If it has 3 wires to the motor (one for a starting winding), it would be more difficult to measure the right one there.

Have a meter with "inrush"? Not all meters give an accurate peak reading.

Also take running current, to compare. I expect starting surge to be 5x rating for running current. Could be more than 5x actual measured current depending on load.