INTRODUCTION
This chapter covers the electrical power systems for SNs 23-003 through 24-229 and 25-
003 through 25-064, excluding 25-061.
DC electrical power on the Learjet 20 series airplanes is provided by two engine-driven
starter-generators. Backup DC electrical power is supplied by two batteries. A ground
receptacle allows connection of the ground power unit. Ground power may be used for
system operation or engine starting. AC electrical power is provided by two or three solid-
state inverters located in the tailcone.
GENERAL
The electrical system incorporates a multiple
bus system for power distribution. The system
is interconnected by relays, current limiters,
overload sensors, and circuit breakers which au-
tomatically react to isolate a malfunctioning
bus. Manual isolation is also possible by open-
ing the appropriate circuit beakers. It is possi-
ble to power the entire DC and AC electrical
systems from the airplane batteries, a single en-
gine-driven generator, or a GPU.