What is the phonemoena of 3 ph 6 wire squirel cage induction motor one phase S-FTerminals are interchanged?

We are running a 60 hp, 3-ph, 440v, squirrel cage induction motor for pump application. No load currents are almost equal. When started loading (Opening of Dischage Valve) the current shoots up 2to3 times rated current and tripping on OL. Suspect one phase reversal i.e Start-Finish of one winding. Is it correct or any other possibilities? please explain?