TM 55-1730-229-12
TO 35C2-3-473-1
On the 83-360D the 28 vdc signal is
and through a filter to the spring and
routed directly to the CURRENT LIMIT
ambient
pressure
regulated
control
SELECTOR switch S11, which then
pressure
regulator.
Regulated
air
operates the surge control valve,
pressure is routed through a restrictor
whether the pneumatic power is ON or
and a rate control orifice and across a
OFF. This valve is needed to off load
torque motor controlled valve. The
the GTE compressor to eliminate
torque motor control valve applies the
stall. This is necessary when large
regulated air to a pneumatic actuator,
shaft horsepower is required.
which opens or closes the attached valve
plate.
d. Overtemperature Protection.
During
full-load operations using electrical
NOTE
and/or hydraulic power plus pneumatic
power, the LCV functions to prevent
See Table 4-2, Malfunction 62
excessive engine exhaust gas temper-
(step 5) for test.
atures. When the PNEUMATIC POWER switch
is set to ON, the LCV will maintain a
a. Inspect. (See Figure 4-56)
full open position until exhaust gas
temperature (EGT) approaches the control
(1) Remove roof (paragraph 4-16).
point (1230F/666C). At this time the
ECU applies a signal to the LCV torque
(2) Inspect load control valve (LCV)
motor to adjust the valve plate to main-
(2) for security of installation,
tain the control point EGT. The sequence
loose components, and for damage.
will provide a nearly constant bleed
Replace LCV if cracked or dented.
air pressure at a reduced value in the
event of over temperature conditions.
(3) Check visual position indicator
Without this capability, the EGT would
on left side of LCV below solenoid
be exceeded, and the ECU would shutdown
(with engine shutdown). Indicator
engine.
should be in the closed position. Re-
place LCV if indicator is not in
e. Hose Air Dump Solenoid Valve.
This
closed position.
solenoid valve (21) is open when the
PNEUMATIC POWER switch is set to OFF.
b. Remove. (See Figure 4-55).
Setting switch to ON applies a voltage
to the solenoid, closing the valve. The
(1)
Open
pneumatic
hose
access
purpose of this solenoid valve is to
door.
relieve pneumatic hose pressure prior to
disconnecting hose from aircraft.
(2) Remove engine
access
cover
A
pressure
transducer
(17)
monitors
pneumatic
(3) Disconnect two hoses (11) con-
pressure to aircraft. Pressure is con-
nected to manifold (12).
verted to an electrical signal, which is
sent to a meter on the control panel.
(4) Disconnect tubing assembly (22)
from fitting (16) on manifold (12).
g. Surge Control Valve (SCV).
This
solenoid valve (31) opens when the
(5) Cut and remove lockwire, and
CURRENT LIMIT SELECTOR switch S11 is set
disconnect electrical connector (3,
to 45KW or 1000 A on the 83-360A and
Figure 4-56) from LCV.
when set to AH-64D on the 83-360D. On
the 83-360A the 28 vdc signal to open
(6) Loosen marmon clamp (1, Figure
the valve is routed through both the
PNEUMATIC POWER switch S8 and the
LCV (15).
CURRENT LIMIT SELECTOR switch S11 so
that the surge control valve will not
(7) Loosen marmon clamp (1, Figure
open whenever pneumatic power is ON.
4-56) holding LCV.
