7-74
P/N 11934-003
Section 7
Cirrus Design
Airplane Description
SR20
prevented from powering the Main Buses by the isolation diode
interconnecting the MCU distribution buses. Loads on circuit breaker
panel Main Buses are shed by pulling the individual circuit breakers.
The 15-amp AVIONICS circuit breaker on Main Bus 1 powers all loads
on the Non-Essential Avionics Bus. Power from the 15-amp
AVIONICS circuit breaker is also controlled through the AVIONICS
master switch on the bolster switch panel.
Non-Essential Buses
The circuit breaker panel contains two Non-Essential Buses, the Non-
Essential Equipment Bus and the Avionics Non-Essential Bus. The
Avionics Non-Essential Bus is powered through the 15-amp
AVIONICS circuit breaker on Main Bus 1 and is discussed above. The
Non-Essential Equipment Bus is powered by ALT 1 and BAT 1 from
the MCU Main Distribution Bus through a 25-amp circuit breaker. ALT
2 and BAT 2 are prevented from powering the Non-Essential
Equipment Bus by the isolation diode interconnecting the MCU
distribution buses. Loads on the Non-Essential Equipment Bus are
shed by pulling the individual circuit breakers.
Ground Service Receptacle
A ground service receptacle is located just aft of the cowl on the left
side of the airplane. This receptacle is installed to permit the use of an
external power source for cold weather starting and maintenance
procedures requiring reliable power for an extended period. The
external power source must be regulated to 28 VDC. The external
power control contactor is wired through the BAT 1 MASTER switch
so that the BAT 1 switch must be ’on’ to apply external power.
Refer to Section 8, Ground Handling, Servicing, and Maintenance
, for
use of external power and special precautions to be followed.
Convenience Outlet
A 12-volt convenience outlet is installed in the center console. The
receptacle accepts a standard cigarette-lighter plug. The outlet may
be used to power portable entertainment equipment such as CD
players, cassette players, and portable radios. 28 VDC power for the
convenience outlet is supplied through the 3-amp 12VDC OUTLET
circuit breaker on the Non-Essential Bus.
Revision A5
Summary of Contents for SR20
Page 10: ...1 2 P N 11934 003 Section 1 Cirrus Design General SR20 Intentionally Left Blank Revision A3 ...
Page 22: ...2 2 P N 11934 003 Section 2 Cirrus Design Limitations SR20 Placards 2 21 Revision A6 ...
Page 308: ...9 2 P N 11934 003 Section 9 Cirrus Design Supplements SR20 Intentionally Left Blank Reissue A ...