Cirrus DESIGN SR20 - Low Voltage on Essential Bus; Low Voltage on Main Bus 1 or Main Bus 2; Original Issue

Cirrus Design Section 3
SR20 Emergency Procedures
P/N 11934-004 3-25
Low Voltage on Essential Bus
ESS BUS Warning
Illumination of ESS BUS Warning indicates that the voltage output for
alternator 1 or alternator 2 is less than 24.5v for more than 20 seconds
or greater than 32.0v. This is usually associated with an alternator 1 or
alternator 2 failure and will be displayed in combination with a M BUS
1 or M BUS 2 voltage annunciation for the corresponding alternator.
If ESS BUS Warning 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
Low Voltage on Main Bus 1 or Main Bus 2
M BUS 1 or M BUS 2 Caution
Conduct the following procedure if either of the annunciations listed
below are displayed.
Illumination of M BUS 1 or M BUS 2 Caution indicates that the
corresponding alternator voltage output is less than 24.5v. This is
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
ESS BUS
M BUS 1 M BUS 2
Original Issue