Electrical Faults - SDMO R33C3 User And Maintenance Manual

LEROY-SOMER

3.3 - Electrical faults

Fault Action
Connect a new battery
No voltage at of 4 to 12 volts to
no load on terminals E- and E+,
start-up respecting the polarity,
for 2 to 3 seconds
Voltage too
Check the drive speed
low
Voltage too Adjust AVR voltage
high potentiometer
Voltage Adjust AVR stability
oscillations potentiometer
Voltage
Run at no load and
correct at no
check the voltage
load and too
between E+ and E- on
low when on
the AVR
load (*)
(*) Caution : For single-phase operation, check that the sensing wires coming from the AVR are correctly connected to the
operating terminals
Check the AVR, the
Voltage
surge suppressor, the
disappears
rotating diodes, and
during
replace any defective
operation (**)
components
(**) Caution : Internal protection may be activated (overload, open circuit, short-circuit)
12
Installation and maintenance
R438
A.V.R.
Effect
The alternator builds up and its
voltage is still correct when the
battery is removed.
The alternator builds up but its
voltage does not reach the rated
value when the battery is
removed.
The alternator builds up but its
voltage disappears when the
battery is removed
Correct speed
Speed too low
Adjustment ineffective
If no effect : try normal / fast
recovery modes (ST2)
Voltage between E+ and E-
SHUNT < 20 V
AREP / PMG < 10V
Voltage between E+ and E-
SHUNT > 30V
AREP / PMG > 15V
The voltage does not return to the
rated value.
Warning : after operational testing,
replace all access panels or covers.
238/242
3971 en -
Check/Cause
- Lack of residual magnetism
- Check the connection of the voltage
reference to the AVR
- Faulty diodes
- Armature short-circuit
- Faulty AVR
- Field windings disconnected
- Main field winding open circuit - check the
resistance
Check the AVR connections (AVR may be
faulty)
- Field windings short-circuited
- Rotating diodes burnt out
- Main field winding short-circuited - Check
the resistance
Increase the drive speed
(Do not touch the AVR voltage pot. (P2)
before running at the correct speed.)
Faulty AVR
- Check the speed : possibility of cyclic
irregularity
- Loose connections
- Faulty AVR
- Speed too low when on load (or U/F bend
set too high)
- Check the speed (or U/F bend set too
high)
- Faulty rotating diodes
- Short-circuit in the main field. Check the
resistance
- Faulty exciter armature.
- Exciter winding open circuit
- Faulty exciter armature
- Faulty AVR
- Main field open circuit or short-circuited
2010.11 / f