Standby Electrical System Malfunctions - Textron Cessna Grand Caravan Ex 208B Pilot's Operating Handbook And Faa Approved Airplane Flight Manual

SECTION 3 CESSNA
EMERGENCY PROCEDURES MODEL 208B 867 SHP
GARMIN G1000
ELECTRICAL POWER SUPPLY SYSTEM
MALFUNCTIONS
(Continued)

STANDBY ELECTRICAL SYSTEM MALFUNCTIONS

An operational check of the standby electrical system is performed by
following the Normal Procedures, Before Takeoff Checklist. With the
generator supplying the electrical load and the STBY ALT PWR switch
ON, neither the white STBY PWR ON or amber STBY PWR INOP
annunciators should be shown and the ALT AMPS indicator should
show 0 amps.
If the amber STBY PWR INOP annunciator is shown, it indicates that
the standby alternator has no output. If a line voltage surge or
temporary condition has tripped the Alternator Control Unit (ACU)
offline, then cycling the STBY ALT PWR switch to OFF, then back ON,
will reset the ACU and restore standby alternator power.
If the standby electrical system is carrying more than 10 amps of the
electrical load, the white STBY PWR ON annunciator will be shown and
the ALT AMPS indicator will indicate the amount of current being
supplied by the standby electrical system.
To attempt to restore main power, refer to AMBER GENERATOR OFF
ANNUNCIATOR COMES ON procedure. If this attempt is successful,
the standby electrical system will revert to its normal no-load condition
and the amber STBY PWR ON annunciator will not be shown. If main
electrical power cannot be restored, reduce nonessential loads as
necessary to remain within the 75-amp capability of the standby
electrical system. Loads in excess of this capability will be indicated by
an amber ALTNR AMPS annunciation.
If the reverse current protection of the ACU fails, an amber ALTNR
AMPS annunciator will come on when reverse current is less than -8
amps. The pilot should disconnect the standby alternator by positioning
the STBY ALT PWR switch to OFF.
FAA APPROVED
3-58
208BPHCUS-00
U.S.