Baudoulin 4M11G Maintenance Manual page 117

Maintenance Manual of 4M11 Series Diesel Engine For Land Power Generators
Check the phase output voltage of alternator
(This voltage shall be approximately one half
of B+ output voltage.)
The malfunction symptom is not solved after
above checking.
d) Unstable charging voltage
Vehicle symptom
The voltmeter indicates the charging during
normal running of engine, but the pointer
fluctuates and the reading can't be read (or the
charging indicator lamp turns off occasionally).
e) Alternator noise
Vehicle symptom
There is an abnormal
noise during running of
alternator.
Malfunction 4: Unstable charging voltage
Loose belt or belt run-out for
alternator
systems.
Looseness or poor contact at
connections of charging circuit
Contamination of collector ring,
excessive wear of electric brush, or
softening or breakage of electric
brush spring
Damage of regulator
Malfunction 4: Unstable charging voltage
Fault Detection
The fixing bracket of alternator is
deformed or is too close to other
external housings.
Looseness or slip of alternator belt
Loose alternator pulley
Oil shortage or damage of alternator
bearings
Low noise within alternator
Observe the battery surfaces for cleanliness and
dryness and check whether the wiring terminals
and clamps are in good fit. Replace as soon as
possible in event of any damage.
If there is high difference between phase terminal
(W/R/AC) output voltage and normal output and
the voltage drop is high when the alternator is
loaded, the alternator rectifier bridge or stator is
malfunctioned and the checking and replacement
shall be considered.
Replace alternator regulator, rotor, or whole
alternator.
Fault Detection
or related
Improve strength of fixing bracket and
adjust assembly status.
Replace engine belt.
Tighten pulley.
Replace alternator bearing
The stator coil is short circuited. Replace
109
Solution
Tension belts
pulley alternator and
pulley systems.
Check and
connections of charging
circuit
Disassemble
contaminants or replace
electric brush or electric
brush spring
Replace the regulator.
Solution
for
related
tighten