TM 55-1730-229-12
TO 35C2-3-473-1
surge control valve L1H-2 to open
Vdc. The circuit is completed to
even when the pneumatic system is
ground
via
fuel
level
sensor
on. The surge control valve does
(transmitter) MT1. The fuel level
not open at 30 KW setting of the
sensor is a variable resistor. The
CURRENT LIMIT SELECTOR switch S11
resistance changes with the level of
on the 83-360D.
fuel in the fuel tank. The value of
resistance for a given level of fuel
(3) The load control valve is
controls the amount of voltage
enabled
(grounded)
when
the
applied to the meter. As the fuel
PNEUMATIC POWER switch 1S8 is set
level changes, the resistance changes
to ON. Operation of the load
and the meter indication changes. Low
control valve is then controlled
fuel level switch S1Q closed when
by the electronic control unit as
there is 17 gallons or less of fuel,
a function of EGT (engine exhaust
remaining, and illuminates LOW FUEL
gas temperature). The PNEUMATIC
caution lamp 1DS5. Low fuel pressure
POWER switch applied dc power to
switch S5 closes when fuel pressure
illuminate PNEUMATIC POWER light
drops below 2 psi, and illuminates
1DS13, and to close pressure
LOW FUEL PRESS lamp 1DS6.
relief valve L1. The switch also
e. Pneumatic Control System. (See
applies dc power via current
Fig. FO-7) The pneumatic control
limiting resistor R6 to PSIG
system
consists
of
meter
1M7,
PNEUMATIC meter 1M7. Zener diode
resistor R6, zener diode TB1-CR1,
TB1-CR1 limits the voltage across
pressure transducer MT2, pressure
the meter to +12 vdc. The circuit
relief valve L1, and load control
is
completed
to
ground
via
valve. Maintenance of the load
pressure transducer MT2. The
control valve, pressure relief valve,
resistance
of
the
pressure
and pressure transducer is covered in
transducer and thus the meter
section XII.
indication is a function of
pressure in the pneumatic output
hose.
(1) All AGPUs are equipped with a
surge control valve. The surge
control valve is used to bleed off a
CONTROL SYSTEM FOR MAINTENANCE.
portion of the GTE compressor output
to delay the onset of compressor
WARNING
stall. This increased the available
shaft horsepower for high electrical
Battery power (24 vdc) may be
or hydraulic loads.
The surge
present at terminals of electrical
control valve is opened when the
components whenever battery is
CURRENT LIMIT SELECTOR switch S11 is
connected. Ac power (115 vac) may
set to the highest current limits.
be present when engine is running.
To prevent shock hazard, flash
(2) On the 83-360D, power to operate
burns, or equipment damage,
the surge control valve is routed
observe the following precautions:
through the PNEUMATIC POWER switch
1S8 to the 45 KW and 1000 amp pins on
1. Shut down engine and disconnect
the CURRENT LIMIT SELECTOR switch. On
battery before opening control
serial numbers 1036 and higher, the
panel or extending lower electrical
surge control valve also opens at the
tray.
30 KW setting if the CURRENT LIMIT
SELECTOR switch S11. On the 83-360A
2. Shut down engine and dis-
the surge control valve will not open
connect battery before contacting
if the PNEUMATIC POWER 1S8 is ON. On
any electrical terminal with
the 83-360D, a jumper is installed on
body or tools.
the PNEUMATIC POWER 1S8 allowing the
