Troubleshooting
Problem
Absence of output voltage
No-load voltage too low or too high 1)
Corrected no-load voltage too low
with load
Unstable tension
Possible cause
GENERATOR
1)
Voltage switch in position 0
2)
Voltage switch faulty
3)
Protection tripped due to overload
4)
Differential protection device tripped. (Differential
switch, differential relay)
5)
Protection devices defective
6)
Alternator not sparked
7)
Alternator defective
Incorrect motor running speed
2)
Voltage regulating device (where it is assembled)
defective or requires calibration
3)
Alternator defective
1)
Incorrect motor running speed due to overload
2)
Load with cos j less than 0.8
3)
Alternator defective
1)
Contacts malfunctioning
2)
Irregular rotation of motor
3)
Alternator defective
Diesel engine
Solution
1)
Check position
2)
Check connections and working of the switch, repair
or replace
3)
Check the load connected and diminish
4)
Check on the entire installation: cables, connections,
utilities connected have no defective sheathing which
may cause incorrect currents to ground
5)
Replace
6)
Carry out external spark test as indicated in
alternator manual. Ask for intervention of Service
Department
7)
Check winding, diodes, etc. on alternator (Refer to
alternator manual)
Repair or replace.
Ask for intervention of Service Department
1)
Regulate speed to its nominal no-load value
2)
Adjust regulator device as indicated in alternator
manual, or replace. For generators with double
voltage control AVR and COMPOUND, act on the
excitation circuit as shown in the alternator manual.
3)
Check winding, diodes, etc. on alternator (Refer to
alternator manual)
Repair or replace
Ask for intervention of Service Department
1)
Check the load connected and diminish
2)
Reduce or rephase load
3)
Check winding, diodes, etc. on alternator (Refer to
alternator manual)
Repair or replace
Ask for intervention of Service Department
1)
Check electrical connections and tighten
2)
Ask for intervention of Service Department
3)
Check winding, diodes, etc. on alternator (Refer to
alternator manual)
Repair or replace
Ask for intervention of Service Department
M
40.2.
1
REV.4-03/11