曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
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TM 1-1520-248-10
minutes after which the HEAT ON light will extinguish. The items below will be powered with the ESNTL BUS
Allow 2 minutes after heat cycle termination to allow switch in START. With the ESNTL BUS switch in the
heat transfer inside the battery prior to starting. RUN position, all DC loads will be powered except the
mast mounted sight. However, time on battery power
CAUTION will be greatly reduced. Electrical power is not required
for powered flight. Only the standby compass, clock (if
not digital), barometric altimeter, and airspeed indicator
The installation and use of the second will continue to operate.
battery is to provide increased battery
starting capacity for cold weather
starting. If one battery is depleted and VHF FM No. 1
both batteries are placed on line together
in parallel, starting capacity may be ADU
decreased. Therefore, ensure both
batteries are sufficiently charged prior to ECU
starting.
(OH-58D) ESC
Aircraft modified by Army direction from a single to a
dual battery installation, without installing a charger- Engine oil bypass
monitor, can sustain damage to the electrical system if
batteries are charged simultaneously. After start and Force trim
before placing the DC GEN switch in the ON position,
one of the batteries shall be turned OFF. Once one Fuel boost
battery is sufficiently charged, the other can be brought
Anticollision light
on line for charge. Monitor S-GEN LD% for indication
that high charging rate has passed. When S-GEN LD% Starter
has dropped to 70% or less, the other battery may be
switched on for charging. Ignition
e. Power Failures. In the event of total failure of DC generator reset
all power generating systems, an 80% fully charged
battery will provide 5 to 6 minutes of power to all bus Position lights
systems. Power to the battery emergency bus alone
can be provided for 25 to 30 minutes. The following Searchlight
loads are on the battery emergency bus and will
continue to function from battery power after failure of Cockpit utility lights
AC and DC generators:
Cockpit flood lights
NVG power supplies
Vertical scale instruments
Bus interconnect
Standby attitude indicator
Engine transducer
Pitot heater
Rotor transducer
MCPU L Transmission transducer
MCPU R Fuel quantity
Pilot MFD Jettison left
Jettison right
MFK
f. Failure Analysis. Refer to the following step for
RFD a failure analysis when a single electrical subsystem
failure occurs. The failed unit(s) are identified by a
ICS caution message on the multifunction display.
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TM 1-1520-248-10
Figure 2-20. Heating, Ventilating, and Avionics Cooling
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TM 1-1520-248-10
(1) AC Generator Failure. Caution Message:
RECT FAIL
Caution Messages: DC generator picks up loads.
AC GEN FAIL
RECT FAIL
g. External Power. External power receptacles are
provided for application of both AC and DC electrical
AC generator is isolated. power while on the ground. With DC external power
applied, engine starting and systems checkout may be
Rectifier (TRU) is off. accomplished. Application of AC external power allows
operation and checkout of all AC systems.
MMS is off.
Particle separator blower is off. 2-65. DC ELECTRICAL POWER DISTRIBUTION
SYSTEM.
HELLFIRE missile system launcher power lost.
a. DC Power System. The DC power distribution
Inverter and starter-generator pick up remaining system is divided into bus systems. The three distinct,
loads. interrelated systems are the DC power assured bus,
battery emergency bus and DC essential bus (fig. 2-
(2) Starter-Generator Failure.
21).
b. Transformer Rectifier Unit (TRU). The
Caution Messages:
transformer rectifier unit (TRU) is rated at 200
DC GEN FAIL
amperes, 28 Vdc. The TRU is located in the aft
INV FAIL
electrical compartment. As AC primary power is
generated by the AC generator, power is fed to the
Starter-generator isolated. TRU which converts the AC input to DC primary output.
DC output from the TRU energizes the TRU relay and
Inverter off. connects the TRU to the DC essential bus. The TRU
also provides a secondary source of power to the DC
No battery charging. power assured bus and the battery emergency bus.
(3) Inverter Failure.
c. Starter-Generator. With the DC GEN switch in
the DC GEN position and starter-generator output at 28
Caution Message: volts, the generator provides power to the battery
INV FAIL generator bus and the battery emergency bus. The DC
power assured bus relay i s i n turn energized,
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TECHNICAL MANUAL OPERATOR’S MANUAL FOR ARMY OH-58D HELICOPT(25)
