TM 55-4920-221-14
107. NO AC GENERATOR LOAD.
Probable Cause
Possible remedy
Defective high-low switch Replace (paragraph 132).
Probable Cause
Possible remedy
S4
Improper position of load Connect load links E2 and
Frequency meter impedor Replace (paragraph 115).
links E2
load disconnect links E1
box defective
in
accordance
with
Meters M5 or M6 defective Replace (paragraph 91).
connection
board
103. METER M8 NOT INDICATING.
instruction plate.
3 kw ac generator load
Place all switches in ON
Probable Cause
Possible remedy
switches S18, 19, 21 or
position.
Incorrect setting of the dc Place switch in appropriate
22 in OFF or CENTER
ammeter terminal selector
scale as determined by in-
position
S43
put terminals.
AC generator load switches
Replace defective switches.
Loose or corroded shunt
Clean and tighten.
S18, 19, 20, or 21 de-
connections
fective
Dc ammeter terminal selec- Replace (paragraph 131).
Open load resistor ...............Check load bank and
tor (S43) defective
replace defective resistor
Meter M8 defective .............Replace (paragraph 91).
as necessary (paragraph
104. METER M9 NOT INDICATING.
Probable Cause
Possible remedy
108. NO AC GENERATOR VARIABLE LOAD.
Voltmeter fuse F1 blown or Replace.
Probable Cause
Possible remedy
defective
0-1 Kw, ac generator load Place in ON position.
Dc voltmeter circuit selec-
Place selector in appropriate
switches S15, 16, or 17 in
tor S27 in wrong position
test position.
OFF or CENTER posi-
for test being performed
tion
No reading on low scale of Depress pushbutton on dc
Variable controls R1, 2, or Turn counterclockwise to
meter
voltmeter switch S40 to
3 in maximum resistance lower resistance value.
read on low scale.
position
Dc voltmeter switch S40
Replace (paragraph 133).
Open load resistors .............Check load bank and
defective
replace
defective
Meter M9 defective .............Replace (paragraph 91).
resistors (paragraph 127).
105. METER M7 NOT INDICATING.
Ac voltmeter M4 defective ..Replace (paragraph 91).
Probable Cause
Possible remedy
109. NO DC GENERATOR LOAD.
Loose or corroded shunt
Clean and tighten.
Probable Cause
Possible remedy
connection
Improper position of load Connect in accordance with
Improper input terminal
Connect input to proper ter-
links E2 on connection
connection board instruc-
connections
minals.
board
tion plate.
Meter (M7) defective
Replace (paragraph 91).
Dc generator load switches Place in ON position.
106. NO INVERTER LOAD.
S30-38 in OFF position
Probable Cause
Possible remedy
Defective de generator load Replace (paragraph 134).
Improper position of load Connect load links E2 and
switch
links E2 on connection
load disconnect links E1
Open load resistor......................Check and replace as
board
in
accordance
with
necessary (paragraph 127).
connection
board
Connection link between
Tighten and/or replace link.
instruction plate.
BATT and GEN termi-
Inverter load switches S12, Place three inverter load
nals on relay pad is loose
13, or 14 in OFF or CEN- switches in ON position.
or missing
TER position
110. NO R4 FIELD RHEOSTAT CONTROL USING
Variable controls R1, 2, or Turn three variable controls
BATTERY.
3 in maximum resistance counterclockwise to lower
Probable Cause
Possible remedy
position
resistance value.
Rheostat regulator switch Place in RHEOSTAT posi-
Inverter load switches S12, Replace (paragraph 136).
S25 in REGULATOR
tion.
13, or 14 defective
position
Open load resistor ...............Check load rack and
Rheostat switch S26 in
Place in TEST position.
replace defective resistor
BATT. GEN position
Rheostat regulator switch Replace (paragraph 135).
Ac voltmeter M4 defective ..Replace (paragraph 91).
S25 or rheostat switch
S26 defective
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