Beechcraft Duchess 76 - Page 227

BEECHCRAFT
Duchess 76
Section VIII
Handling, Serv and Maint
Preflight the airplane.
If the airplane is to be stored longer than 30 days, refer to
the appropriate airplane shop manual and Avco Lycoming
Service Letter L180.
EXTERNAL POWER
To supply power for ground checks or to assist in starting.
use only an external power source that is negatively
grounded. The receptacle is located on the right side (ME-
1 through ME-440). or on the left side (ME-441 and after).
of the aft fuselage.
CAUTION
On 14-volt airplanes, the power pin for external
power is connected directly to the battery and
continually energized. Turn off alternato r
switches, all electrical and avionics switches.
and turn on battery switch before connecting the
auxiliary power unit plug. Assure correct polarity
(negative ground) before connecting auxiliary
power unit.
On 2B-volt airplanes, a reverse polarity diode
protection system is between the external
power receptacle and the main bus. With
external power applied, the bus is powered.
Turn on the battery switch only with all other
switches including avionics switches off before
connecting the auxiliary power unit. Assure
correct polarity before connecting external
power.
Observe the following precautions when connecting an
external power source:
1. Remove the protective cover from the external power
receptacle of the airplane.
January 1982
8-11