Troubles, Causes And Corrective Action; Preventive Maintenance; Warranty - Pegasus 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 alternators
when operating in parallel.
Generated voltage decreases
when load is applied, and it
doesn't return.
Alternator 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 alternator 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 Pegasus Technology.
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.
Alternator excitation voltage
excessively low.
Third harmonic of the auxiliary coil is
high.
Lack of sensing.
Faulty electronic circuit.
Sensing voltage incompatible with
regulator.
Pegasus technology
Schroeder - SC - Brazil
Phone: 55 (47) 3374-6300
contato@pegasustech.com.br
www.pegasustech.com.br
Corrective Action
Connect phase sequence correctly.
Correctly polarize the CT in the phase shown below:
S1
S2
Alternator
P1
P2
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 15Ω/200W resistor in series with field.
Eliminate auxiliary coil and proceed with the
connections according to the diagrams of page 17.
Check if alternator phases are present in the sensing.
If the regulator is encapsulated, replace it.
Load