MMD Equipment AirMan SDG125S-6A6, Instructional Manual

Page: 57 / 67

6. Maintenance/Adjustment
6
-
4
Symptom Cause Counter measures
Even when
operated at a rated
speed, no voltage
or too low voltage
generated.
(1) Faulty voltmeter
(2) Poor tightening of terminals
(3) Broken or short-circuited winding of
generator main unit
(4) Faulty AVR
(5) Faulty silicon rectifier (mounted on
generator rotor)
(6) Faulty exciter
(7) Broken or short-circuited circuit to
exciter field winding
(8) AVR frequency selection switch is not set
to meet the frequency to be operated.
(9) Function circuit protector (CP) for AVR
protection
Check/change
Check/repair
Check/repair
Check/change
Check/change
Check/repair
Check/repair
Check/select
Reset
Too high voltage
generated when
set at the rated
frequency
(50Hz/60Hz),
Voltage will not
drop even when
the voltage
regulator
controlling knob is
turned. (1) Loosened or disconnected wiring, or
connector to AVR
(2) Faulty AVR
(3) Broken wire or poor contact of AVR
variable resistor
Check/repair
Check/change
Repair or change
Unstable voltage
generation
(1) Poor tightening of each terminal
(2) Faulty AVR
(3) Function circuit protector (CP) for AVR
protection
Check/repair
Check/change
Reset
Please contact your nearest dealer if you find it difficult to repair by yourselves.
Please refer to the engine operation manual for troubles concerning the engine.