MMD Equipment 25S-3A3 - Manual (Page 61)

7. Maintenance/Adjustment
7-4
Symptom Cause Countermeasures
Even when operated
at rated speed, no
voltage or low
voltage generated. Faulty voltmeter
Poor tightening of terminals
Broken or short-circuited winding of
generator main unit
Faulty AVR (Automatic Voltage
Regulator)
Faulty silicon rectifier (mounted on
generator rotor)
Faulty exciter
Broken or short-circuited winding of
exciter field
Check/change
Check/tighten
Check/repair
Check/change
Check/change
Check/repair
Check/repair
High voltage
generation when
generator rotates at
a rated speed.
Voltage does not
decrease even when
the automatic
voltage regulator
knob is turned. Loosened or disconnected wiring, or
connector to AVR
Faulty AVR
Broken wire or poor contact of AVR
variable resistor
Check/connect
Check/change
Repair or change
Unstable voltage
generation. Poor tightening of each terminal
Faulty AVR
Check/tighten
Check/change
Over speed warning
lamp goes on. Engine speed too high
Maladjustment or failure of controller
Check/adjust
Replace or adjust
The items in time
chart (5.2.1) do not
function. Maladjustment or failure of controller
Faulty pickup sensor
Disconnection, loosening of connectors
and cable removal
Replace or adjust
(Contact our distributor
or us)
Check/replace
Check/retighten
Three-phase breaker
will not be switched
“ON” Output terminal cover is open
Faulty door switch
Check/
Replace
Contact your nearest dealer if you find the repair to be difficult.
Refer to the engine operation manual for trouble concerning the engine.