Woodward 2301E-ST, Installation And Operation Manual

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Manual 26694 2301E-ST
Woodward 92
25. Unload the system and reverse phase B CT wires on the same terminals.*
26. Apply full load and measure the load signal. Record this reading and compare the four readings on
the list.
27. Unload the system. Remove the phase B CT wires and connect them to the pair of CT input
terminals that produced the highest positive load signal reading and with the polarity that produced
the highest positive load signal reading.*
28. Remove tape and disconnect the phase C CT wires. Connect these two wires to the remaining pair
of CT input terminals.
29. Apply full load, measure the load signal and record this reading.
30. Unload the system and reverse the phase C CT wires on the same terminals.*
31. Apply full load, measure the load signal and record this reading.
32. Unload and shut down the system. Compare the two readings.*
33. Connect the phase C CT wires to the same pair of CT input terminals, but in the polarity that
produced the highest positive load signal reading.
34. Re-label each wire with the phase designation of the terminal that it is now connected to.
35. Remove the burden resistors and terminal block.
Load Calibration Adjustment
For this procedure, the generator must be running isochronously and not paralleled.
Start the prime mover and apply full load. With the Watch Window at the B** DISPLAY LOAD INFO **
sheet and observe 02 LOAD SENSOR INPUT (KW). If this reading does not match external
instrumentation, adjust calibration gain and offset under the Service Menu M**LOAD SENSR AND
DROOP** until Watch Window value matches metering. The values should match at all intermediate
points.
*–If values at full load (or a lower reading proportional to a load less
than 100%) cannot be obtained and the phasing has been checked
and is correct, the current transformers are probably the wrong size.
The current-transformer output must be from 3 to 7 A (5 A nominal)
at full load.
When in parallel operation in isochronous mode or on an isolated bus, generator speeds must be the
same. If they are not equal, load sharing will not remain proportional as the load varies. Any difference in
loads between the units can be corrected by adjusting the Load Gain. Increasing the LOAD GAIN will
cause that generator to carry less load. If stability problems occur when in parallel operation at a
particular load signal reading, reduce the reading by reducing the LOAD GAIN and reduce the load signal
reading setting of all other generators in the system to the same reading. When the load signal readings
of all generators in a system are reduced, the load sharing gain will be reduced and this may result in
some loss of load sharing sensitivity.
It may be necessary to reduce the load signal reading of each unit in the system to as low as 3 volts in
cases of extremely poor system dynamics. If your system requires a load signal reading as low as 3 volts,
consult Woodward for suggestions for possible remedies.
Released