Electric Power Generation
1
Installation and maintenance
1
5
8
7
4
en - 2020.01 /
a
TALA40
Low Voltage Alternators - 4 pole
4.5 - Electrical faults
Fault
Action
Effect
Check/Cause
The alternator builds up and
its voltage is still correct
- Lack of residual magnetism
Connect a new
when the battery is removed
No volt- battery of 4 ta 12 The alternator builds up but - Check the connection of the voltage reference
age at no volts ta termi-
its voltage does not reach
ta theAVR
load on nais F1 and F2. the rated value when the
- Faulty diode
start-up respecting the
battery is removed
-Armature short-circuit
polarity. for 2 ta 3
seconds
The alternator builds up but - Faulty AVR
- Field windings open circuit (check winding)
its voltage disappears when - Main field winding open circuit (check the
the battery is removed
resistance)
Check the AVR connections (possible AVR failure)
- Field windings short-circuited
Correct speed
- Rotating diodes burnt out
Voltage Check the drive
- Main field winding short-circuited (check the
tao low speed
resistance)
Speed tao low
lncrease the drive speed (do not touch the AVR
voltage pot. before running at the correct speed)
Voltage AdjustAVR volt- Adjustment ineffective
Faulty AVR
tao high age potentiometer
Voltage
- Check the speed : possibility of cyclic irregularity
oscilla-
Adjust AVR stabil-
- Loose connections
tians
ity potentiometer
- Faulty AVR
- Speed tao low when on load
Voltage
Voltage between F1 and F2 - Check the speed
correct
Run at no load
SHUNT< 6V -AREP < 10V
at no load and check the
- Faulty rotating diodes
and tao voltage between Voltage between F1 and F2
low when F1 et F2 on the SHUNT> 10V -AREP >
- Short-circuit in the main field (check the
on load AVR
15V
resistance)
(*)
- Faulty exciter armature (check the resistance)
(*) Warning : During single-phase operation. check that the sensing wires from the AVR are connected ta the
correct output terminais.
Check the AVR.
Voltage the surge
- Exciter winding open circuit
disap-
suppressor. the The voltage does not return - Faulty exciter armature
pears
rotating diodes. ta the rated value
- Faulty AVR
during
and replace any
- Main field open circuit or short-circuited
operation defective
components
(**) Warning : The AVR internai protection may eut in (overload lost connection. short circuit).
16
LEROY-SOMER'"
