ACR LGT TYPE ACFT OVERSHOT CLB CLRNC ALT DURING AN ACFT ELECTRICAL PROBLEM.

Narrative

WHILE CLBING THROUGH FL190 IN RAIN; LIGHT TO MODERATE TURB AND LIGHT ICING WITH AUTOPLT AND AUTO THROTTLES ENGAGED; GENERATORS RELAYS BEGAN TO CYCLE OPEN AND CLOSED WITH AS MANY AS 9 OVERHEAD ANNUNCIATOR MESSAGES BEING DISPLAYED INTERMITTENTLY. AFTER APPROX 10-15 SECONDS THE SITUATION STABILIZED WITH L GENERATOR FAILURE INDICATED. AUTOPLT AND AUTO THROTTLES HAD DISENGAGED; BOTH MAPS DISPLAYED FAILURE; FMS RTE AND DEACTIVATED; AND CAPT'S ADI HAD FAILED TO A BLANK SCREEN. CAPT TRANSFERRED CTL OF ACFT TO FO AS HE HAD AN OPERABLE ADI. ABOUT THIS TIME; THE ALT ALERT SOUNDED. ALTIMETER INDICATED 21400 -- ALT SELECT WINDOW SHOWED 21000. BOTH FO AND I THOUGHT OUR CLRNC WAS TO FL230. I IMMEDIATELY CALLED ZTL TO VERIFY OUR ALT CLRNC WHILE THE FO DSNDED TO FL210. ZTL RESPONDED WE WERE NOW CLRED TO FL270. THE FO RESUMED A CLB TO FL270. WE THEN ACCOMPLISHED THE ABNORMAL PROC AND REINSTATED THE AUTOPLT; AUTO THROTTLES AND RELOADED THE FMS DATA. WE COULD NOT RESTORE THE L GENERATOR TO PWR THE L AC BUS EVEN THOUGH VOLTS (AND) FREQ WERE NORMAL AFTER A RESET. APU WAS STARTED AND PLACED ON THE L AC BUS. FLT THEN CONTINUED TO DEST NORMALLY. CREW ALLOWED ELECTRICAL FAULT TO DISTRACT US FROM PRIMARY DUTY OF FLYING THE ACFT. I AM STILL UNCERTAIN IF ELECTRICAL RELAYS CYCLING CHANGED DIGITAL DISPLAY OF THE ALT SELECT WINDOW FROM 23000 OR IF WE WERE BOTH INCORRECT IN THINKING OUR CLRNC WAS TO FL230.