What was found
(CAN) NEARING TOP OF CLIMB, CIRCUIT BREAKERS BEGAN TO TRIP. FUEL PUMP CIRCUIT BREAKERS FOR LEFT SIDE, TCAS, STALL WARNING, EQUIPMENT COOLING, WINDOW ANTI-ICE, RADIO ALTIMETER. RETURNED TO YUL, NO EMERGENCY DECLARED, LANDED WITHOUT INCIDENT. REPLACED NR 1 GENERATOR BREAKER AS PER MM , DUE A PHASE MISSING FROM GENERATOR. OPERATION CHECKED OK ON SECOND RUNUP.