S
ECTION
3: E
MERGENCY
P
ROCEDURES
C
IRRUS
D
ESIGN
E
LECTRICAL
S
YSTEM
E
MERGENCIES
SR20
3-28
P/N 11934-005
ESS BUS Warning
ESS BUS
High or Low Voltage on Essential Bus
1. Essential Bus Voltage (ESS) .............................................................CHECK
◆
If Essential Bus Voltage is greater than 32 Volts:
a. Main Bus 1 and Main Bus 2 Voltages (M1 and M2)..............CHECK
b. Perform appropriate
Checklist.
◆
If Essential Bus Voltage is less than 24.5 Volts:
Checklists.
◆
If unable to restore at least one alternator:
a. Non-Essential Loads................................................................ REDUCE
❍
If flight conditions permit, consider shedding:
(1)Air Conditioning
(2)Landing Light
(3)Pitot Heat
(4)Cabin Fan
(5)Nav Lights
(6)Strobe Lights
(7)Audio Panel
(8)COM 2
2. Land as soon as practicable (Battery reserve only).
Procedure Complete
• CAUTION •
Dependent on battery state, flaps and landing light may be unavail-
able on landing.
• N
OTE
•
Essential Bus voltage is high or low. High voltage indicates alter-
nator voltage regulator failure; will typically be associated with
high M1 and/or M2 voltages and
and/or
messages.
Low voltage indicates dual failures of Alternators 1 and 2, will typi-
cally be associated with low M1 and M2 voltages,
and
messages.
Reissue A