DURING TAXI IN A319 FO TURNS OFF NUMBER 2 GENERATOR THEN SHUTS OFF NUMBER 1 ENGINE REMOVING ALL ELECTRICAL POWER. FATIGUE FROM FOUR DAYS OF FLYING IS CITED AS CAUSE.

Narrative

FLT WAS THE END OF A 2 DAY WITH 2 LATE NIGHT FINISHES. WHILE TAXIING TO THE RAMP AFTER LNDG; THE CAPT ASKED ME TO SET THE AIRPLANE UP FOR SINGLE ENG TAXI. AS PER SOP; I DISCONNECTED THE #2 GENERATOR WHEN HE TOLD ME HE WAS CLR OF THE STEERING. THEN THE CAPT ASKED ME TO SHUT DOWN THE #2 ENG. IN MY TIRED STATE; I REACHED DOWN AND SHUT THE ENG MASTER SWITCH FOR THE #1 ENG; LEAVING THE ACFT WITH 'NO' ELECTRICAL PWR (EXCEPT BATTERIES). AFTER REALIZING WHAT I HAD DONE; I RE-ENGAGED THE #2 GENERATOR; WHICH CAUSED THE STEERING AND BRAKES TO MOVE ERRATICALLY. THE CAPT WAS TAXIING SLOWLY; SO NOBODY WAS INJURED; NOR WAS ANYTHING DAMAGED. THE PAX PROBABLY JUST NOTICED THAT THE ACFT HAD GONE DARK. AFTER PARKING NORMALLY AT THE GATE; I EXPLAINED TO THE CAPT THAT I WAS SO TIRED THAT I HAD SHUT OFF THE WRONG ENG MASTER SWITCH. I FEEL THAT I HAD SUCCUMBED TO ACUTE FATIGUE CAUSED BY 2 LATE NIGHTS IN A ROW; JUST AFTER COMPLETING A PREVIOUS TRIP WITH 2 EARLY MORNINGS IN A ROW. I AM NOT A CARELESS PLT; BUT RATHER FEEL THAT I HAD BECOME SO TIRED AT THE END OF THE FLT THAT I DIDN'T DISCERN THE DIFFERENCE BTWN THE #1 AND #2 ENG MASTER SWITCHES. RATHER THAN REMAINING FOCUSED; I WAS OPERATING OFF OF GROSS MOTOR SKILLS AND ROTE MEMORY; WHICH GOT ME IN TROUBLE. PLEASE LET OTHER PLTS KNOW NOT TO LET THEIR VIGILANCE EASE UNTIL THEY ARE STANDING ON THE JETBRIDGE (OR; BETTER YET; IN THEIR DRIVEWAY).