WEG AVR-A-OPT-16, Installation, Operation And Maintenance Manual

Page: 19 / 51

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Automatic Voltage Regulator – AVR-A-OPT-16 | 19
14 PROBLEMS, CAUSES AND CORRECTIVE ACTIONS
Problems Causes Corrective Actions
- There is circulation of reactive power
between generators when operating in
parallel.
- Phases sequence (R-S-T) incorrectly
connected.
- CT connections are inverted.
- Droop adjustment excessively low.
- Connect phase sequence correctly.
- Correctly polarize the CT in the phase shown
below:
- Increase droop adjustment, rotating trimpot
P2 clockwise (CW).
- Generated voltage decreases when load
is applied, and it doesn’t return.
- Dropping speed of the driving machine.
- Under frequency protection engaged.
- Correct speed regulation.
- Adjust Under frequency protection by rotating
trimpot P5 clockwise (CW).
- Generator voltage does not increase.
- Residual voltage excessively low.
- Terminals F (+) and F (-) are inverted.
- With the regulator switched- on, use external
battery (12Vcc) to force excitation (*).
- Invert F (+) and F (-).
- Generated voltage oscillates at no load.
- Dynamic not well adjusted.
- Generator excitation voltage excessively
low.
- Adjust trimpots P3 and P4;
- Insert 10 Ω /100W resistor in series with field.
- Voltage oscillates at a specific load point.
- Third harmonic of the auxiliary coil is
high.
- Eliminate auxiliary coil and proceed with the
connections according to the diagrams of page
13.
- Voltage surges.
- Lack of sensing.
- Faulty electronic circuit.
- Sensing voltage incompatible with
regulator.
- Check if generator phases are present in the
sensing.
- If the regulator is encapsulated, replace it.
(*)For battery diesel generator where the generator neutral is grounded battery should always be used independently.
15 PREVENTIVE MAINTENANCE
Periodical inspections of the equipment are required to ensure they are clean, dust and moisture free. It is essential that all
terminal and connections are kept free from corrosion.
16 WARRANTY
See Installation and Maintenance Manual for WEG G Line Generator.
WEG Equipamentos Elétricos S.A.
International Division
Av. Prefeito Waldemar Grubba, 3000
89256-900 - Jaraguá do Sul - SC - Brazil
Phone: 55 (47) 3276-4002
Fax: 55 (47) 3276-4060
www.weg.net
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