TM 5-6115-271-14
TO 35C2-3-386-1
TM-05926A-14
NAVFAC P-8-613-14
Table 5-1. Troubleshooting (Cont'd)
Table 5-1. Troubleshooting (Cont'd)
MALFUNCTION
MALFUNCTION
TEST OR INSPECTION
TEST OR INSPECTION
CORRECTIVE ACTION
CORRECTIVE ACTION
1. GENERATOR FAILS TO BUILD UP RATED
1. GENERATOR FAILS TO BUILD UP RATED
VOLTAGE (Cont'd)
VOLTAGE (Cont'd)
(5) Stop the generator set, and connect
(6) Reassemble generator set and repeat
steps (1) and (2).
the load cables.
b. Models MEP-016A, MEP-016C and
(6) Repeat steps (2) through (4) above.
MEP-026A, MEP-026C
b. Voltage Regulator Testing (DC Unit).
(1) Disconnect load cables and turn cir-
(1) Start generator set and allow it to
cuit breaker switch to OFF position.
warm up.
(2) Start generator set, place circuit
(2) Observe the voltmeter on the front of
breaker switch to ON position and observe set
the control box. If exciter, rotor, or stator is
voltmeter and tachometer for proper reading
defective, there will be no voltage reading on
the set voltmeter.
(should be 28 V at 3600 RPM).
(3) Using a multimeter, check load ter-
(3) Manually flash the field windings as
prescribed in paragraph 4-20e(2), If stator and
minals to verify reading on set voltmeter. If
voltage is low, adjust it to specifications with
rotor are good, voltage will appear and hold on
set voltmeter, with 100% load applied.
the variable resistor.
(4) If voltage comes up, proceed with
(4) If the voltage is still low and the var-
iable resistor will not correct the deficiency,
generator operation. If not, stop the engine
check exciter voltage across terminals 20 and
and check continuity of exciter stator by
21 of the voltage regulator terminal board.
loosening terminal 20 or 21 on the voltage
This voltage will vary but should be about 30
regulator terminal board and measure across
volts. If voltage at terminals 20 and 21 of the
the exciter stator leads with a multimeter. If
voltage regulator terminal board fails to meet
bad, then replace the stator assembly.
(5) Remove generator from generator set
specifications, the voltage regulator is defec-
tive and should be fully tested and repaired
(see para 8-3),
10-2), from the stator assembly. Remove
diodes from the exciter rotor (20, fig. 10-5) and
(5) If voltage is satisfactory, stop the
test with a multimeter. Replace any bad
generator set and attach the load cables.
diodes. If diodes are good, replace the rotor
(6) Repeat steps (2) through (4) above.
assembly.
Repair a defective voltage regulator (para
8-3).
(6) Reassemble generator set and repeat
steps (1) and (2).
Step 2. Inspect the exciter rotor for loose connections
or breaks. Test the exciter rotor as follows:
Replace a defective exciter rotor (para
10-2).
a. Model MEP-021A, MEP-021C
Step 3. Inspect the stator and rotor for loose connec-
(1) Start generator set and allow it to
warm up.
tions or breaks. Test the stator and rotor (see
malfunction 1, step 2).
(2) Observe the voltmeter on the front of
the control box. If exciter, rotor, or stator is
Replace the stator and/or rotor (para 10-2).
defective there will be no voltage reading on
2. GENERATOR VOLTAGE TOO HIGH
the set voltmeter.
Inspect the voltage regulator for loose wires, corrod-
(3) Manually flash the field windings as
ed wiring, metal-to-metal contact, incorrect wiring, or
prescribed in paragraph 4-20e(2). If stator and
other darmage. See malfunction 1, step 1 and test the
rotor are good, voltage will appear and hold on
voltage regulator.
set voltmeter, with 100% load applied.
Repair a defective voltage regulator (para
(4) If voltage comes up, proceed with
8-3).
generator operation. If not, stop the engine
and check continuity of exciter stator by
3. GENERATOR FAILS TO SUPPLY LOAD
loosening terminal 20 or 21 on the voltage
Step 1. Inspect the stator for loose connections or
regulator terminal board and measure across
breaks, Refer to malfunction 1, step 2 and test
the exciter stator leads with a multimeter. If
the rotor.
bad, then replace the stator assembly.
Redate a defective stator (para 10-2).
(5) Remove generator from generator set
Step 2. Check the rotor for loose connections or
breaks. Refer to malfunction 1, step 2 and test
10-2) from the stator assembly. Remove diodes
the rotor.
from the exciter rotor (17, fig. 10-4) and test
Replace the rotor (para 10-2).
with a multimeter. Replace any bad diodes. If
Step 3. Inspect the voltage regulator for loose wires,
diodes are good, replace the rotor assembly,
corroded wiring, metal to metal contact, incor-
rect wiring, or other damage. Refer to malfunc-
tion 1, step 1 and test the voltage regulator.
Repair a defective voltage regulator (para
