Jacobsen Eclipse 322, Руководство по ремонту

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4-68 4222983 Second Edition
ELECTRICAL
4
Genset Circuit—Theory of Operation
Power Circuit
Unswitched 48V power is available from stud 3 through
150A fuse (F8) and 0.02 ohm resistor (R6) to key switch
terminal A and liquid crystal display (LCD) terminal
J11-8.
When the key switch is turned to the run position, 48 volts
is provided from key switch terminal B to liquid crystal
display (LCD) ignition terminal J11-5, powering up the
LCD.
With the LCD powered up, a ground is provided from the
LCD switched power contactor output terminal J11-10 to
the power distribution unit (PDU) terminal J1-4. With a
ground provided to J1-4, the 12 and 48 volt switched
power contactors are energized.
With the PDU 12 volt switched power contactor
energized, 12 volts is provided through 0.02 ohm resistor
(R12) to the main control unit (MCU) 12 volt power input
terminal J2-8. PDU terminal J1-5 also provides 12 volts
to splice E and then from splice E, 12 volts is provided to
MCU 12 volt power input terminal J2-6. With the PDU 48
volt switched power contactor energized, 48 volts is
provided to circuit breaker (F4) and MCU 48 volt power
input terminal J2-7, powering up the MCU.
The PDU also provides 12 volt switched power from the
12V switched power contactor (K3) to generator control
unit terminals J36-J1 and J36-K1, powering up the
controller. PDU terminal J1-11 provides 12 volts to
genset fan relay terminals 86 and 30.
Genset Circuit
As the engine turns, the permanent magnet generator
produces three-phase alternating current (AC). The AC
current is rectified by the diode blocks and direct current
(DC) is provided to PDU terminal stud 3.
The generator control unit (GCU) monitors the speed of
the generator and the 48 volt power output level. As the
demand on the 48V power bus changes, the generator
control unit (GCU) adjusts the speed of the engine
turning the 48V generator by changing the position of the
throttle actuator.
The permanent magnet generator and rectifier
temperature sensors allow the GCU to monitor the
temperature of these two components. The GCU
calculates the amount of generator output current by
measuring between the 150A shunt resistor terminals.
If the GCU determines the 48 volt power bus level is out
of normal operating range, the GCU outputs a fault code
signal to the main control unit (MCU).
To output a fault code, the GCU genset fault output
terminal (J36-A2) provides a signal to the MCU genset
fault input terminal (J3-10). The MCU decodes this signal
and instructs the LCD to display the fault code.
If the GCU determines that one or both temperature
sensors are not within the normal operating range, a fault
code is outputted. The GCU will set the engine speed to
idle when a fault occurs.
GCU turns on the genset fan as needed. To turn on the
fan, the GCU fan relay output terminal (J36-B1) provides
a ground to genset fan relay terminal 85, energizing the
relay. With the relay energized, current flows between
relay terminals 30 and 87 to the genset fan, turning on
the fan.
When the GCU whisper mode on input terminal is
activated, the GCU will set the engine speed to idle and
the buffer battery pack provides power to the system.