TM 55-1730-229-12
TO 35C2-3-473-1
(2) If the control panel CURRENT
maximum. Maximum output is 500 amps
LIMIT SELECTOR switch 1S11 is in a DC
for 1 minute, 1000 amps for 6
position and there are no dc voltage
seconds.
or over current faults, the GCU
(5) The possible generator dc
system logic applies 28 vdc to the
coil of dc output contactor K2. When
along with the protective action and
the DC POWER switch 1S12 is set to
fault lamp indications. After a fault
ON, the contactor is energized and
occurs, the GCU system fault logic is
connects the generator 28 vdc output
latched until the control panel DC
to the dc output cable. The contactor
POWER
switch
1S12
is
set
also applies the 28 vdc to illuminate
(momentarily) to RESET, or MASTER
the DC POWER ON lamp 1DS21. DC output
switch is set to OFF. The TRU on the
voltage is indicated on the DC VOLTS
83-360D is protected by an overheat
meter 1M11 and dc output current is
indicator. Activation of this switch
indicated on DC AMPS meter 1M12. On
will illuminate the DC OVER CURRENT
the 83-360D, all the AGPU's DC output
light (DS19) on the control panel.
power is supplied by the TRU, which
Neither the TRU nor the GCU can open
is powered from the AC output of the
the DC contactor to prevent continued
overheating of the TRU. Activation of
must remain in the AC mode to
the overheat indicator is most often
regulate this AC output. The GCU has
caused by a failure of the TRU cool-
been disconnected from the DC
contactor K2 and a jumper has been
to the 83-360D.
installed to allow the contactor to
close whenever the DC POWER switch is
(6) The dc-to-ac inverter converts
set to ON.
dc power (generator dc output or
battery power) to 115 vac 60 Hz power
(500 watts). The inverter provides
dc output continuously for the
for operation of low power ac
following possible faults:
under
equipment that cannot be operated
voltage, over voltage, over current,
form generator 400 Hz ac output.
or high ripple. On the 83-360D, the
GCU can only operate in the AC mode.
b. Ac Power Generation and Control.
DC current limiting and DC voltage
This system is shown schematically in
fault monitoring are not provided.
the ac sections of the ac/dc
(4) The under voltage limit is set
at 22 vdc and the over voltage is set
(GCU), ac output contactor K1,
at 32 vdc. The ripple limit is 2 to 3
volts (peak to mean) from 10 Hz to 40
KHz. The over current limit is set by
control panel CURRENT LIMIT SELECTOR
J4, and associated control panel
switch 1S11 at 200, 500, 700, or 1000
controls and instruments.
amps. When a fault is detected, the
GCU system logic deactivates the dc
(1) As described in paragraph a.,
contactor or removes generator field
the generator includes PM stator
excitation to protect the generator
windings that provide power for GCU
operation
and
generator
field
also illuminates the appropriate
excitations. When the control panel
control panel fault lamp (VOLTAGE
CURRENT LIMIT SELECTOR switch is in
FAULT DS18 or OVERCURRENT 1DS19). The
any AC position, the GCU varies the
TRU used on the 83-360D, is a rugged
generator exciter field as required
solid-state power converter currently
to keep the generator ac output
used on the AH-64A helicopter to
voltage within limits. A thermal
provide essential DC power. It has a
switch near the ac winding provides
minimum continuous output voltage of
an indication when the temperature
26 vdc at a 250 amp and 25 vdc at a
of the ac winding exceeds normal
350 amp output. Ripple is 1.5 volt
Change 8
4-209