As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DIVERTED DUE TO GEN 1 OFF BUS CAS APPROXIMATELY 2.5 HOURS INTO A FLIGHT FROM KSFO TO KPHL. CREW FOLLOWED QRH, DESCENDED TO FL310, AND STARTED THE APU. AT APPROXIMATELY 3 HOURS INTO THE FLIGHT, ADDITIONAL ALERTS WERE RECEIVED: ENGINE 1 EXCEEDANCE AND ENGINE 1 LOW OIL PRESSURE. THE CREW REDUCED ENGINE 1 POWER TO IDLE PER QRH INSTRUCTIONS. THE AIRCRAFT LANDED SAFELY AT KSTL. REPLACED GEN 1 IAW EMB-545/550 AMM 24-31-01.