14 PROBLEMS, CAUSES AND CORRECTIVE ACTIONS
Problems
Generated voltage decreases when load is
applied, and it does not return.
Alternator voltage does not increase.
Generated voltage oscillates at no load.
Voltage oscillates at a specific load point.
Voltage surges.
(*) For battery diesel generator where the alternator 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 Alternators.
Table 14.1
Causes
▪
Dropping speed of the driving machine;
▪
Under frequency protection engaged.
▪
Residual voltage excessively low
▪
Terminals F (+) and F (-) are inverted.
▪
Sensing voltage is under pattern or not
connected.
▪
Dynamic not well adjusted.
▪
Alternator excitation voltage excessively
low.
▪
Third harmonic of the auxiliary coil is
high.
▪
Lack of sensing.
▪
Faulty electronic circuit.
▪
Sensing voltage incompatible with
regulator.
WEG Group - Energy Business Unit
Jaraguá do Sul - SC - Brazil
Telefono: 55 (47) 3276-4000
www.weg.net
www.weg.net
Corrective Actions
▪
Correct speed regulation.
▪
Adjust Under frequency protection by rotating
trimpot P5 clockwise (CW).
▪
With the regulator switched- on, use external
battery (12Vdc) (*) to force excitation.
▪
Invert F (+) and F (-).
▪
Connect your sensing voltage to the
compatible pin to the nominal voltage from
your generator following the instructions
contained in this manual.
▪
Adjust StbPI and StbD trimpots;
▪
Check if the U/F limiter is working, if it is,
increase the machine speed.
▪
Check the polarity of the F+ and F-
connections in relation to the generator field
cables;
▪
Insert 10Ω/100W resistor in series with field.
▪
Eliminate auxiliary coil and proceed with the
connections according to the diagrams of
pages 43, 44 or 45.
▪
Check if alternator phases are present in the
sensing.
▪
If the regulator is encapsulated, replace it.
Automatic Voltage Regulator – GRTA-2D l 17