3-24 P/N 11934-004
Section 3 Cirrus Design
Emergency Procedures SR20
Electrical System Emergencies
Alternator Failure
The most likely the cause of the alternator failure is a wiring fault, a
malfunctioning alternator, or a malfunctioning control unit. Usually,
electrical power malfunctions are accompanied by an excessive rate of
charge or a discharge rate shown on the ammeter.
If it is necessary to reduce electrical loads due to an alternator
malfunction, switch off electrical components and/or systems that are
not essential for the current flight conditions rather than pulling circuit
breakers. Load shedding in this manner will prevent accidental circuit
breaker disconnection and loss of power to flight-critical systems.
• Caution •
Alternators in this airplane are self-exciting. These alternators
require battery power for alternator starting; however, once
started, the alternators will provide self-generated field power
to continue operation in case of a battery failure. To assure
alternator restart power is available if the alternators fail, the
batteries should not be turned off during flight.
High Voltage on Main Bus 1 or Main Bus 2
M BUS 1 or M BUS 2 Warning
Conduct the following procedure if either of the annunciations listed
below are displayed.
Illumination of M BUS 1 or M BUS 2 Warning indicates that the
corresponding alternator voltage output is higher than 32.0v. This is
also usually associated with an alternator failure.
If M BUS 1 or M BUS 2 Caution is illuminated, perform the
corresponding ALT 1 or ALT 2 checklist, otherwise conduct the
following procedure
1. If On-Ground .................................CORRECT PRIOR TO FLIGHT
2. If In-Flight..................................LAND AS SOON AS PRACTICAL
M BUS 1 M BUS 2
Original Issue
To Next Page
Loading...
