Woodward 2301E-ST, Installation And Operation Manual

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Manual 26694 2301E-ST
Woodward 89
With proper MPU, gear size and MPU-to-gear clearance, speed measurement should be capable down to
100 Hz. Check the speed sensor for visible damage. Standard MPU clearance is recommended to be
between 0.25 and 1.0 mm (0.010 and 0.040 inch) at the closest point. Make sure that the gear has less
than 0.5 mm (0.020 inch) diametric run out. See manual 82510,
Magnetic Pickups and Proximity
Switches for Electronic Governors
.
Current Transformer (CT) Phasing Check
This control contains internal current transformers. Due to their low
impedance, shorting their inputs is not effective. The current input
must be removed from the control and shorted externally.
HIGH VOLTAGE—Never disconnect any wire attached to load sensor
terminals 4 through 9 when the prime mover is running unless
temporary 0.5
Ω , 20 W resistors are installed as shown in Figure 5-1
and all load is removed. The current transformers can develop
dangerously high voltages when open circuited while the prime
mover is running.
1. Go to the B** DISPLAY LOAD INFO ** service menu and observe 02 LD SENSOR INPUT (KW) and
05 LOAD SIGNAL OUT (VDC) to measure the load sensor output. The displayed values are not yet
calibrated to read Kilowatts, but are used here for indication.
2. Start the prime mover. With the generator operating in the isochronous mode and not in parallel,
load the generator to as near full load as possible.
3. Use a clamp-on ammeter and measure the per phase current of the Current transformer output.
Check that current in each of the three CTs is equal. In a balanced three phase system the Load
Signal Out reading will be approximately:
Load Signal Out = kW Input Calibration Gain X 0.1 X AMPs (rms reading of one phase).
The kW Input Calibration Gain setting is in Service Menu M**LOAD SENSR AND DROOP**.
A clamp-on ammeter is recommended to eliminate the need to open CT wiring to insert an ammeter
in series with the CT output.
4. If the Load Signal Out Reading is within 10% of the above calculation, the PT/CT phasing is correct.
If the phasing is incorrect, proceed to the Phase Correction Procedure. If the phasing appears
correct, skip the Phase Correction Procedure and go to the Load Calibration Adjustment procedure.
If after completing the LOAD SENSOR CALIBRATION and DROOP
adjustments, the control loading is extremely sensitive to changes in
the power factor when operating in parallel, complete the phase
correction procedure.
The most accurate calibration is made at full load. However, if it is
not possible to run the generator set at full load, run it at less than
full load and reduce the voltage reading given in this calibration
procedure proportionally. For example: run a 200 kW generator set at
100 kW and divide all voltages given in this calibration procedure by
2. If you reduce the load in this manner, be sure to reduce it by the
same amount throughout the calibration procedure.
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