Honda Aircraft Company
HA-420
SYSTEMS
POM
DESCRIPTION
HJ1-29000-005-001
October 30, 2016
1-173
Two power distribution units (PDU) perform primary power distribution
for the airplane systems. These units contain contactors, solid state
relays, and electronic and processor controls. The PDUs also contain
circuit breakers that route power to non-essential systems. Essential
system circuit breakers are installed on the pilot’s and co-pilot’s circuit
breaker panels (CBP) outboard of each crew seat. Additional circuit
breakers are mounted on the outboard surface of the PDUs for items that
do not require access during flight.
POWER GENERATION AND STORAGE
Starter-Generators
When the ENGINE START button is pushed, the starter-generator
engages the starter function and the engine starting sequence is initiated.
During start, the bus system isolates the number 2 battery. The loads that
are normally powered by the number 2 battery are powered by the
number 1 battery through the bus tie contactor. At approximately 50%
N
2
, the starter disengages and the starter-generator begins operating as a
generator. The start sequence can be aborted at any time by pushing the
PUSH TO DISC switch.
Selecting the L or R GENERATOR switch to OFF opens the line
contactor and isolates the generator from the electrical system. Cycling
the switch OFF, then NORM acts as a reset command to the GCU. In the
NORM position, the generator will automatically come online whenever
it is available except when external power is powering the aircraft.
Batteries
The electrical system includes two lead-acid batteries, each with a 28
Amp-hour design capacity. Batteries are located behind the electrical
service doors in the front of the wing-to-body fairing.
FOR TRAINING PURPOSES ONLY
