Beechcraft Duchess 76 - Page 205

BEECHCRAFT
Duchess 76
CAUTION
Section VII
Systems
Description
On 28-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.
When auxiliary power is desired, connect the clamps
of the
power cable to the remote power source, ensuring proper
polarity. Turn OFF the
AL T switches and ensure that all
avionics equipment is
OFF, and then turn ON the BATT
switch. Insert the power cable plug into the receptacle, turn
on auxiliary power unit,
and start engine using the normal
starting procedures.
January 1982
7-31