The following steps are intended as a guide for installation and initial startup of the regulators. Site specific procedures should incorporate these steps to ensure
completeness.
1. Verify hardware, proms, and board revisions using the GE Control System Toolbox (toolbox) and job specific software supplied with the equipment. Check the hardware including the shunt supplied, dynamic discharge resistor, charge control resistor, and options supplied.
If changes to proms or circuit boards are required, a Full Calc in toolbox may be needed. Contact GE Industrial Systems before changing any values generated by the Full Calc if unsure of the correct settings.
2. Verify jumpers and switch settings as specified in the toolbox and the requisition elementary. If changes are made, update the a pplication tool databases to keep an accurate documentation of the regulator.
3. Perform a complete wire check of all external connections to the regulator. Inspections for unintentional shorts, induced voltages, correct wiring ampacities, and the like should be made. This will include PT and CT inputs, alarm contacts, trip contacts, and connections to the operator’s interface device. Ground detector connections and other optional equipment should also be checked.
4. With input disconnects open, check incoming ac and dc power for proper levels and polarities. On units with a PMG input, it may not be practical to check the PMG inputs until initial roll of the equipment. At a minimum, a complete wire check of the inputs should be performed.
GEH-6375A User's Guide Chapter 5 Startup Checks • •• • 5-3
5. Energize the dc power supply feed to energize exciter regulator controls. The regulator will go through an initialization process. During this in itialization process, hardware and firmware diagnostic checks are performed. Any faults
generated during the initialization should be corrected before proceeding. If Innovation Series Controller, Mark V, or Mark VI is supplied on the system, communication faults will not be cleared until this device is operational. The LDCC display will default to its normal, de-energized state. It should appear similar to the following.
A S 97% I 0 %
The PSCD board has several LED indications of power supply levels and test points for checking the output of the regulator supplies. Check these testpoints
for appropriate voltage levels. Refer to the t oolbox help messages or the individual board GEI instructions for test points and voltages.
The dc link voltage should also be checked. Variable VAR.1091 should read the corresponding voltage in engineering units and should a gree with the level measured. On the IAXS board, connections PL and NL are the positive and negative link voltages respectively.
6. Turn off the dc supply and repeat the PSCD supply voltage checks for the ac feed to the regulator. The PSCD board voltages will be the same as for the dc feed. The dc link voltage will generally be different than the dc link with only the dc supply voltage. Phase rotation of the ac input is not important in the regulator. But phasing should be checked to ensure accuracy in as built
drawings. If a single phase ac input is used, it must be connected to L1 and L3 leads of the ac input device.
Refer to the control elementaries for proper connections.
If voltage doubling is required, the connections on CTBA-3 and CTBA-4 should be made. Voltage doubling may only be used with a single-phase ac source.
After independent proper operation with both the ac an d dc source voltages are observed, both power sources should be en ergized at the same time. Elimination of either source should have n o noticeable affect on the regulator. Only the dc link voltage may be affected. This check should be performed during power initial checks.
7. Using toolbox, download the appropriate core file to the regulator. After the download is complete, the regulator will again perform a diagnostic check. 8. In order to thoroughly test the operation of the regulator, operation in the
simulator mode is recommended. Place the control core in the simulator mode (EE.570.0=1). See Chapter 6 for operation and scaling information of the simulator. It is also recommended that as much testing as possible be performed in simulator mode. This should help shorten the pre-startup and initial roll checks greatly since control functions, alarms, trips, etc. will have been tested and verified correct.
Note In the simulator mode, the regulator can generate a request for lockout. This can trip the lockout relay unl ess the function is disabled.
9. It may be necessary to place temporary jumpers on inputs to simulate breaker closures or start permissives that may not be operable at this time. Refer to hardware elementaries for specific jumpers required. If temporary jumpers are used, it is important to remember to check the operation of these inp uts from the actual devices at some point during the pre-start process.
5-4 •• • • Chapter 5 Startup Checks EX2000, PWM Digital Regulator GEH-6375A
10. If the operator’s station device is available, start the device and test operation of the controls. Raise and lower signals, alarms, limits, displays and transducer outputs are available in the simulator mode.
11. Close or jumper circuit breaker auxiliary contact (52G) input to simulate online operation.
Change EE.84 value to simulate higher turbine load. UEL settings can be checked by increasing EE.84 lowering the regulator output, and comparing to the capability curve.
Note Return EE.84 value to (152*frequency/60) before opening the 52G contact or the simulator will overspeed and cause a trip.
12. Verification of the operation of the online and offline OEL limiters can be accomplished through the use of the built in simulator and toolbox. A
convenient way to do this is to utilize the two input summation (2 Input Sum) block that is programmed between the REF2 block output and the CORE block
EFR@SP input. EFR@SP is the setpoint for the field regulator. The summation block was added to the pattern for test purposes only. Input 1 of this block is the
normal field regulator reference supplied by REF2 output. Input 2 can be pointed to the output of the background test oscillator. In this manner the
regulator can be easily stepped. a. Offline OEL
While in manual regulator, raise the excitation level until the field current exceeds the offline OEL pickup level. The system goes into off-line OEL. Lower the reference to see that the OEL condition resets. Step the reference into OEL and observe the response. Return the summation block test input to zero. b. Online OEL
While in manual regulator and with a bout 90% MW load, increase the Vars until field current is above 102% of AFFLex. The PRIT1 block begins to accumulate and after a time delay activates the OEL limiter. Lower the setpoint and then step the reference so that the system goes back into on-line OEL. Observe the response and be aware that if a very large step is used, the signal level detector pickup level is also exceeded. After 10 seconds, the exciter field current will be
limited to 125% of AFFLex and when PRIT1 times out it will limit to 100% of AFFLex.
13. After completion of the tests, disconnect the test oscillator.