Electrical Faults - SDMO R 340 U User And Maintenance Manual

LEROY-SOMER

4.3 - Electrical faults

Fault Action
No voltage at Connect a new battery
no load on of 4 to 12 V to terminals
start-up F- and F+, 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 F+ and F- 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.
Voltage Check the AVR, the
disappears surge suppressor, the
during rotating diodes, and
operation (**) replace any defective
components
(**) Caution: Internal protection may be activated (overload, open circuit, short-circuit)
Installation and maintenance
R 450
AVRs
Measurements
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
Voltage between F+ and F-
AREP/PMG < 10 V
Voltage between F+ and F-
AREP/PMG > 15 V
The voltage does not return to the
rated value
Caution: After operational testing or
troubleshooting, replace all access
panels or covers.
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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
- Revolving field coil open circuit. Check the
resistance
- Check the AVR connections and settings
(AVR faulty)
- Field windings short-circuited
- Rotating diodes burnt out
- Revolving field coil short-circuited
- Check the resistance
Increase the drive speed
(Do not touch the AVR voltage pot. (P1)
before running at the correct speed)
- Faulty AVR
- 1 faulty diode
- Check the speed: possibility of cyclic
irregularity
- Loose connections
- Faulty AVR
- Speed too low when on load
(or U/F knee-point set too high)
- Check the speed
(or U/F knee-point set too high)
- Faulty rotating diodes
- Short-circuit in the revolving field coil.
Check the resistance
- Faulty exciter armature
- Exciter winding open circuit
- Faulty exciter armature
- Faulty AVR
- Revolving field coil open circuit or
short-circuited
- Overload (see LED)
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