TM 11-6125-240-12
breakers and inverter.
Repair wiring as necessary.
c. Refer inverter to higher
c. Dc brushes not making
category maintenance.
contact with commu-
tator.
d. D C input circuit open. , . . . . . . . . . . . . . . . . . . d. Check wiring and connection
to the inverter for an
open circuit. Repair or
replace as necessary.
e. Armature jammed . . . . . . . . . . . . . . . . . . . . . . e. Refer inverter to higher
category maintenance.
a. Connect a power test set to
a. Ac circuit open.
Inverter runs but fails to deliver
the test point jacks on
proper voltage or frequency.
the front of the regu-
lator (fig. 1-2), and
start the inverter. If
indication is between
109 and 121 Vac, 390 and
410 Hz, check exterior
wiring and connections
for an open circuit, and
repair. If indication
is not as specified,
refer inverter to higher
category maintenance.
b. Remove ac electrical end
b. Slipring brushes not
caps and check for
making contact with
broken brushes or
slipring.
springs. Refer inver-
ter to higher category
maintenance.
c. Refer inverter to higher
c. Regulator failure.
category maintenance.
a. Check dc voltage at power
Ac output voltage is low . . . . . . . . . . . . . a. Dc input voltage is low.
supply and correct.
b. Readjust increase volts adjustment
b. Misadjustment of increase
resistor as described in paragraph 3-9.
volts adjustment
resistor.
a. Check dc voltage at
AC output voltage is high. . . . . . . . . . . . . a. DC input voltage iS
power supply and
higher than 30V.
correct.
b. Readjust as described
b. Misadjustment of voltage
adjustment resistor.
c. Refer inverter to higher
c. Regulator failure.
category maintenance.
Refer inverter to higher
Misadjustment of internal
Speed (frequency) is too
category maintenance.
frequency adjustment re-
high or too low.
sistor.
a. Check and tighten con-
Output voltage unstable . . . . . . . . . . . . . a. Loose connections.
nect ions as necessary.
If trouble persists
refer to higher cate-
gory maintenance.
b. Check and refer to high-
b. Poor commutation or
er category mainte-
poor brush contact at
nance.
sliprings.
Refer inverter to higher
Misadjustment of increase
Speed (frequency) is too
category maintenance.
adjustment resistor.
high or too low
a. Check and tighten connec-
a. Loose connections.
Output voltage unstable.
tions as necessary. If
trouble persists refer
to higher category
maintenance.
b. Poor commutation or
b. Check and refer to higher
poor brush contact
at sliprings.
category maintenance.
3-3
