Cirrus SR22 Pilot Operating Handbook page 256

S 7: A
ECTION IRPLANE AND
E S
LECTRICAL YSTEM
Main Buses
The circuit breaker panel MAIN BUS 1 and MAIN BUS 2 are powered by
ALT 2 from the MCU Main Distribution Bus 2 and - in the event of ALT 2
failure - by ALT 1 and BAT 1 from the Main Distribution Bus 2 via the
diode interconnecting the MCU distribution buses through 30-amp fuses
inside the MCU.
The 10-amp AVIONICS circuit breaker on MAIN BUS 1, controlled
through the AVIONICS master switch on the bolster switch panel, powers
all loads on the AVIONICS bus.
The circuit breaker panel MAIN BUS 3 is powered by ALT 1 and BAT 1
from the MCU Main Distribution Bus 1 through a 30-amp fuse inside the
MCU. In the event of ALT 1 failure, BAT 1 will power MAIN BUS 3. ALT
2 is prevented from powering MAIN BUS 3 by the isolation diode intercon-
necting the MCU distribution buses 1 and 2.
Non-Essential Buses
The circuit breaker panel NON ESS BUS is powered by ALT 2 from the
MCU Main Distribution Bus 2 and - in the event of ALT 2 failure - by ALT
1 and BAT 1 from the Main Distribution Bus 2 via the diode intercon-
necting the MCU distribution buses through 30-amp fuses inside the
MCU. The Avionics Non-Essential Bus is powered through the 10-amp
AVIONICS circuit breaker on MAIN BUS 1 and is discussed above.
The circuit breaker panel A/C BUS 1 and A/C BUS 2, is powered by ALT 1
and BAT 1 from the MCU Main Distribution Bus 1 through a 30-amp fuse
inside the MCU. In the event of ALT 1 failure, BAT 1 will power A/C BUS
1 and A/C BUS 2. ALT 2 is prevented from powering A/C BUS 1 and A/C
BUS 2 by the isolation diode interconnecting the MCU distribution buses
1 and 2.
7-50
S
YSTEMS
C D
IRRUS ESIGN
SR22
P/N 13772-006
Reissue A