P-9-TM-457-35
T.O. 35C2-3-442-2
TM-07464A-35 TM 5-6115-457-34
(e) If readings are low, replace
(c) If diodes checkout, discon-
e x c i t e r - r e g u l a t o r . If readings are normal
nect wires U135C16 and U134C16 from
or high, test generator diodes for an open
(A11)TB1-2 and TBl-3, connect wires
condition.
together.
b. Removal. Disconnect plug P13 and
(d) Start generator set; if voltage
P9 from the exciter regulator, then remove
builds up check for short circuit in booster
the four screws and nuts securing the as-
transformers CT4, CT5, or CT6, refer to
sembly in position. See figure 6-15.
wiring.
6-76. TEST.
(e) If voltage doesn't build up,
a. Connect the exciter-regulator to
transformer (A11)T1 is defective.
test equipment as illustrated in figure
6-16 and perform test specified in proce-
3. To inspect for the cause of low
dural analysis table 6-7.
output voltage when the generator set is
under load, shut down generator set and
NOTE
check for an open diode (A11)CR1, CR2,
CR3, or CR4. If defective, replace the
exciter assembly.
exciter-regulator schematics.
Refer to these schematics when
(a) If diodes are not defective,
checking individual components
connect ac ammeter (0-25 amp scale) in
for their required values or
series with wire from TB1-6 and TB1-6
operating characteristics.
terminal and measure current from the
booster transformers CT4, CT5 or CT6.
b. Remove test equipment.
(b) With the generator set under
6-77. DISASSEMBLY.
full rated load, the reading should be
14 2 amps. A low reading indicates an
open current transformer (CT4, CT5, or
Refer to figure 6-17 and disassem-
ble the exciter regulator in the order of
CT6).
index numbers assigned. Pay particular
(c) If voltage reading is normal,
attention to the following:
connect a dc ammeter (0-25 amp) in series
NOTE
with the exciter field and a dc voltmeter
(0-30 volt scale) across (A1l)TB1-5(+) and
The exciter-regulator assembly
(A1l)TB1-6.
should be tested prior to disas-
sembly as specified in paragraph
(d) Start the generator set and
6-76. Disassemble the exciter-
measure exciter field voltage and current
regulator assembly to the extent
under full rated load. The reading should
necessary to accomplish repair.
be 10 2 volts dc at 6 to 8 amps for 50/60
a. Remove cover (2, figure 6-17) by
hz units, and 22 4 volts dc at 14 to 16
removing eight screw assemblies (1).
amps for 400 hz units.
6-42
