Troubles, Causes And Corrective Action; Preventive Maintenance; Warranty - WEG GRT7-TH4-R2 Manual De Instalación, Operación Y Mantenimiento

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17 TROUBLES, CAUSES AND CORRECTIVE ACTION

Problems
There is circulation of reactive
power between generators when
operating in parallel.
Generated voltage decreases
when load is applied, and it
doesn't return.
Generator voltage does not
increase.
Generated voltage oscillates at
no load.
Voltage oscillates at a specific
load point.
Voltage surges.
(*)Always use an external battery for diesel gensets where the neutral of the generator is grounded.

18 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.

19 WARRANTY

See the Installation and Maintenance Manual of the G Line generator WEG.
28 l Automatic Voltage Regulator – GRT7-TH4-R2
Causes
Phases sequence (R-S-T) incorrectly
connected.
CT connections are inverted.
Droop adjustment excessively low.
Dropping speed of the driving machine.
U/F Limiter engaged.
Residual voltage excessively low.
Terminals F (+) and F (-) are inverted.
Dynamic not well adjusted.
Generator excitation voltage
excessively low.
Third harmonic of the auxiliary coil is
high.
Lack of sensing.
Faulty electronic circuit.
Sensing voltage incompatible with
regulator.
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
Corrective Action
Connect phase sequence correctly.
Correctly polarize the CT in the phase shown below:
S1
Generator
P1
Increase droop adjustment, rotating trimpot Drp clockwise.
Correct speed regulation.
•Adjust U/F Limiter by rotating trimpot U/F
counterclockwise.
•With the regulator switched- on, use external battery
(12Vcc) to force excitation (*).
Invert F (+) and F (-)
Adjust trimpot Stb;
Insert 15/200W resistor in series with field.
Eliminate auxiliary coil and proceed with the connections
according to the diagrams of page 17.
Check if generator phases are present in the sensing.
If the regulator is encapsulated, replace it.
S2
Load
P2