TM 55-1730-229-12
TO 35C2-3-473-1
(3) An aircraft (AH-64A) type,
These differences should be noted
400 Hertz to 28 VDC, transformer
prior to any maintenance or repair
rectifier unit (TRU) is used on the
actions.
83-360D to power the battery char-
ger, the 60-Hertz inverter and to
(3) Locating the CURRENT LIMIT
start or service DC aircraft. The
SELECTOR switch to the 30 KW setting
TRU is mounted to the front side of
in addition to the 45 KW setting,
the DC cable storage bay. A rubber
will cause the surge control valve
flap is attached to the lid to re-
to open on serial numbers 1012,
duce exposure of the TRU to rain or
1032,
and 1036 through 1155. The
snow. The TRU out-put is connected
con- tinuous bleed of GTE compressor
to the DC contactor as shown on FO-
out- put through a 1/4 inch diameter
5D.
hole in the union at the input to
the su- rge control valve has also
(4) The exhaust ejector assembly
been eli-
minated on these same
on the 83-360D has also been modi-
serial num-
bered AGPUs.
fied to reduce the back-pressure.
This improves the GTE efficiency,
b. Part Number 83-360D. This new
thereby increasing shaft horsepower,
part number has been assigned to
increaseing the pneumatic output and
selected AGPUs used to support the
reducing fuel consumption.
AH-64D, Longbow Apache helicopter
that have been modified by MWO 1-
(5) The continuous bleed of GTE
1730-229-50-2 to upgrade the 400
compressor output on all P/N 83-
Hertz, AC, output and the gas tur-
360D, is plugged and the jumper in-
bine engine performance. The up gra-
stalled on the current limit switch
ded AGPU has a new AC generator, a
for serial numbers 1012, 1032, and
modified
generator
control
Unit
1036 through 1155 is removed. The
(GCU), a transformer rectifier Unit
surge control valve opens only when
(TRU), a modified exhaust ejector,
the CURRENT LIMIT switch is set at
and associated wiring changes. Se-
the AH-64D/90KVA setting. The set-
rial numbers are not changed when
ting of the pneumatic system switch
MWO 1-1730-229-50-2 is applied.
no longer controls the function of
the surge control valve. A muffler
(1) The primary hardware change
has been added to the outlet of the
in corporated by MWO 55-1730-229-50-
surge control valve.
2 is replacement of the generator,
which has a combined 37.5 KVA AC and
(6) The marking on the current
700 amp DC output, with 48 KVA AC
limit selector on the control panel
generator. The 83-360D generator has
have been changed to identify
the
no DC output. The AC generator is
higher AC limits and to indicate
also a self-cooled, continuous duty,
that the DC current limiting and DC
self-excited, brushless unit, but
VOLTAGE FAULT indicator has been
doesn't have the two windings used
disabled. The TRU has only limited
to provide 28 VDC output. The rec-
output. A "MAX. CONT. 350 AMP" la-
tangular box on the top of the gen-
bels has been applied to the con-
nerator is eliminated. It contained
trol panel to indicate the reduced
the DC output terminals and the gen-
DC output. A "MAX. CONT. 130%" label
nerator control unit (GCU) con-
has been applied to indicate the in-
nector, which is located onto the
creased AC rating.
primary housing of the AC generator.
The connections to the output ter-
minals are changed to maintain the
NOTE
proper direction of rotation. (See
There are only minor changes with
(2) The GCU has been modified to
the exterior of the AGPU. The 83-
control the larger capacity AC gen-
360D can be identified by ammo
erator. While the current limits may
identification plate located just
change, this modified GCU may be
below the nameplate and revised
used still be used with the com-
labeling the control panel. The
bined AC/DC generator on the P/N 83-
TRU can be seen on the upper left
360A. Since AC power is still need-
of the DC cableway, just under a
ed, even when only DC is being sup-
6-inch flexible flap marked "83-
plied by the TRU, the CURRENT LIMIT
-360D".
SELECTOR switch is rewired so that
the GCU is always monitoring the AC
output.
