1-13
Change 5
1-15.
TM 55-2835-208-23
A
B
C
D
E
F
G
MAGNETIC PICKUP.
The magnetic pickup provides speed signals to the
electronic sequence unit (ESU) in the aircraft.
ELECTRICAL
HARNESS .
A single harness connects all electrical
components
of the APU to the Main electrical connector.
Connection
to the aircraft electrical system
is through this main electrical
connector
to the harness. Refer to schematic for electrical harness
details.
IGNITION EXCITER.
The ignition exciter
is a capacitor-discharge
type.
The exciter
converts direct-volts input to a high-potential
alternating voltage for ignition.
IGNITION CABLE.
The ignition cable connects the ignition system to
the igniter plug.
IGNITER PLUG.
A shunted-gap type igniter plug provides the igniter
for initial ignition of fuel during start of the APU.
THERMOCOUPLE.
A single-element, chromel/alumel thermocouple is part
of
the electrical harness.
The thermocouple
senses exhaust gas
temperature (EGT) and provides the signal to the ESU. The output
signal is used by
the ESU for overtemperature protection, shutting
down the APU if EGT exceeds safe limits.
METER ASSEMBLY.
The meter assembly provides accurate tracking of APU
operational
hours and number of starts for purposes of maintenance,
