A300 RETURNS TO DEP ARPT AFTER ELECTRICAL ODOR IS DETECTED IN COCKPIT.

Narrative

WHILE CRUISING AT FL300 APPROX 45 MINS INTO FLT; FO RPTED A BURNING RUBBER SMELL ON HIS SIDE OF COCKPIT. I COULD NOT SMELL IT VERY WELL FROM MY SIDE. AFTER CHKING OUT THE SYS; I DECIDED TO CALL THE PURSER FOR A THIRD OPINION. THE PURSER AGREED WITH THE FO. I WAS APCHING A WAYPOINT WHERE WE WOULD LOSE RADAR COVERAGE WITH ZMA. I DECIDED THAT THE SAFEST COURSE OF ACTION WAS TO DIVERT. I REQUESTED A COURSE REVERSAL INITIALLY TO ZZZ1. AFTER CONTACTING DISPATCH; I DECIDED THAT RETURNING TO ZZZ2 WAS A BETTER OPTION. I DECLARED AN EMER AND MADE AN UNEVENTFUL OVERWT LNDG AT ZZZ2. SUPPLEMENTAL INFO FROM ACN 670392: WHILE IN CRUISE I BEGAN TO SMELL WHAT APPEARED TO ME TO BE SOMETHING ELECTRICAL BURNING. I INFORMED THE CAPT AND UTILIZED THE A300 SNIFFER FAN. THE CAPT ASKED THE PURSER TO COME TO THE COCKPIT TO SEE IF HE COULD SMELL THE BURNING FUMES THAT I WAS SMELLING. THE PURSER CONFIRMED WHAT I WAS SMELLING. AT THIS TIME THE CAPT MADE THE DECISION TO RETURN TO DEP ARPT. HE MADE AN UNEVENTFUL OVERWEIGHT LNDG.