ENGLISH
15
6. TROUBLE SHOOTING AND REPAIRS
TROUBLE
POSSIBLE CAUSE
REMEDY
(always to be done with the machine switched off)
The alternator will not
energise (no load voltage
below 10% of rated
voltage).
a) Loose connections.
b) Rotating diodes or surge suppressor
broken.
c) Excitation circuit shorted or interrupted.
a) Check and repair.
b) Check the diodes and change in case they are open or
shortcircuited.
c) Check the continuity and repair.
The alternator will not
energise (no load voltage
20-30% of rated voltage).
Voltage insensitive to AVR
potentiometer's rotation.
a) Fuse (on AVR’s supply line) blown.
b) Connection's cut on the exciter stator.
c) Incorrect connections of exciter stator.
a) Replace the fuse with the spare. If the fuse blows again
check if the exciter stator is short circuited. If everything is
correct, change the AVR .
b) Check the continuity and repair.
c) Reverse the two wires from the exciter stator.
Voltage lower then rated
(output voltage between 50
and 70%).
a) Speed less than rated.
b) Voltage potentiometer unset.
c) Fuse blown.
d)Faulty regulator.
a) Check rpm (frequency).
b) Rotate the potentiometer until the voltage reaches the
rated value.
c) Replace the fuse with spare.
d)Disconnect AVR and replace it.
Voltage too high.
a) Potentiometer V unset.
b) Faulty regulator.
a) Rotate the potentiometer until the voltage reaches the
rated value.
b) Replace AVR.
Unstable voltage.
a) Diesel engine rpm variations.
b) Stability potentiometer unset.
b) Faulty regulator.
a) Check rpm uniformity. Check the diesel engine
governor.
b) Act on AVR’s stability potentiometer.
b) Replace AVR.
7.SPARE PARTS – PART NAME
Pos.
Part name Type / code
201
D side (D:E) bearing
6218 C3 / 346110114
202
N side (N.D.E.) bearing
6313 2RS C3 / 346245065
6
Voltage regulator
M25FA645A
12
VARICOMP device
M40FA621A
7
Fuse (6.3 A, 250 V)
963823040
309
Rotating diode (inverse)
41 HFR 80 / 963821160
310
Rotating diode (direct)
41 HF 80 / 963821161
311
Surge suppressor
M25FA921A
119
Complete rotating rectifier
M25FA464A
