Figure 2A-14.
DC Power Distribution—SNs 23-003 through 24-189,
and 25-003 through 25-029
50A
40A
LH FEEDER
BUS
AMMETER
AMMETER
RH
GEN
V
LH
GEN
RH
BATTERY
LH
BATTERY
EXTERNAL
POWER
RH GEN
BUS
BATTERY
BUS
BATTERY
CHARGING
BUS
LH GEN
BUS
275A
275A
START
RELAY
START
RELAY
50A
40A
NACELLE
HEAT
BATTERY
RELAY
REVERSE
CURRENT
RELAY
REVERSE
CURRENT
RELAY
FREON
150A
NACELLE
HEAT
RH FEEDER
BUS
BUS TIE
50A
APPLICABLE:
SNs 23-003 THROUGH 24-189
SNs 25-003 THROUGH 25-029
EXCEPT NAC HT ON:
SNs 24-181 THROUGH 24-189
SNs 25-025 THROUGH 25-029
2A-14
FOR TRAINING PURPOSES ONLY
LEARJET 20 SERIES PILOT TRAINING MANUAL
FlightSafety
international
DISTRIBUTION
The power distribution system functions as a
single system, but it is really separate systems in-
terconnected by a series of current limiters and
circuit breakers. Figures 2A-14 and 2A-15 illus-
trate power distribution. It is possible to power
almost all DC electrical equipment from one
generator through the interconnected buses or
only certain buses by operation of the bus and/or
bus-tie circuit breakers. Starting with SNs 24-130
through 24-229, and 25-003 through 25-064, all
circuit breakers are accessible to the crew dur-
ing flight. There are certain hot-wired circuits
connected to the batteries and are as follows:
• Left stall warning (all models)
• Right stall warning (all models)
• Cabin door motor (all models)
• Entry lights (door step light, center aisle
l i g h t [ s ] , a n d b a g g a g e c o m p a r t m e n t
lights) (all models)
• Firewall shutoff valve warning lights
(airplanes equipped with glareshield
warning lights)
• Left standby fuel pump (23 models with-
out jet pumps)