As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB-OUT, THE LEFT ENGINE DRIVEN GENERATOR TRIPPED OFF LINE WITH AN AC CROSSTIE LOCKOUT CONDITION. FLIGHT CREW PERFORMED COM PROCEDURES, RETURNED TO DTW, AND LANDED WITHOUT INCIDENT. MAINTENANCE REPLACED THE DIFFERENTIAL PROTECTION CURRENT TRANSFORMER. OPERATIONAL CHECK OK.