Leroy-Somer R452 Installation And Maintenance Manual page 21

LEROY-SOMER
Symptoms
Incorrect regulation.
Response time too long.
Considerable drop in
voltage, on-load.
kVAR not stable between
alternators (reactive current
circulation).
Voltage unstable.
Voltage drop on load
impact.
Overvoltage on voltage
build-up.
INSTALLATION AND MAINTENANCE
VOLTAGE REGULATOR R452
T
ROUBLESHOOTING
Probable causes
- Distortion of the waveform, non-linear load.
- Unbalanced load.
- The speed is not at the correct value.
- Faulty exciter or rotating diodes.
- Faulty regulator.
- Stability adjustment.
- Speed regulator response too slow.
- Vectorial composition fault between the voltage
and the current.
- The parallel operation CT ratio is incorrect.
- Droop potentiometer needs adjusting.
- The no-load voltages are not identical.
- Phases not connected to the sensing correctly.
- The CT is not on the correct phase.
- Frequency unstable.
- Detection at the secondary of a transformer
supplying other devices.
- Faulty regulator.
- The stability potentiometers are incorrectly set.
- Potentiometer P6 is incorrectly set.
- Potentiometer P7 is incorrectly set.
- The stability potentiometers are incorrectly set. - Reset the stability.
Ref. 3563 GB - 4.33 / a - 01.02
Solutions
- Contact ACEO.
- Balance the load or change the sensing points.
- Adjust the speed.
- Check the exciter and the rotating diodes.
- Test it or change it.
- Adjust stability potentiometer P3 and the ST2
jumper.
- Adjust the stability of the speed.
- Check the sensing wiring and the parallel
operation CT wiring.
- Correct the CT ratio.
- Adjust the droop potentiometer.
- Check that all the alternators have the same no-
load voltage value.
- Check the sensing wiring.
- Check the position of the parallel operation CT.
- Check the stability of the drive system speed.
- Install an isolated sensing for the alternator.
- Test it or change it.
- Reset the stability.
- Turn potentiometer P6 fully anti-clockwise.
- Turn potentiometer P7 fully anti-clockwise.
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