Bettis Switch Numbering Convention
TIME / CONDITION EVENT
29.1 Process Overview
Each engine will light off individually and break away its power turbine. Each engine will have the idle trim adjusted to the minimum acceptable NH speed during the break-in period. The NP overspeed via the Micronet will be adjusted to cause a NP overspeed trip at 350 RPM NP for each individual breakaway. The set point will be reset to normal for the remainder of the break-in period and for the actual overspeed tests in Procedure .
On a twin pac, each engine will perform the initial start, breakaway and low speed trip. The OS set point will be reset to nominal and both engines will be run for the PT break-in period. On a power pac, the second engine steps will be omitted.
Enclosure leak checks and inspections will be performed as soon as the first engine reaches idle speed and steady state NP operation. The second engine will then be started and the inspections repeated as necessary.
If both engines cannot be run, each PT may be broken-in separately by uncoupling the non-running engine and operating the unit as a power pac. This will only be possible if the engines have individual exhaust stacks.
29.2 Procedure
1. Ensure that the gas path purge timer, START_SEQ.PRG_TIME_A.IN for engine "A" or
START_SEQB.PRG_TIME_A.IN for engine "B" is set to allow a minimum of 3 complete changes of air volume in the gas turbine flow path. (Default settings are 90 seconds.) This volume should include inlet house, gas turbine, ductwork, SCR or HRSG and exhaust stacks. This setting should be coordinated with the boiler purge cycle as required. The starter can be assumed to sweep the gas turbine at 9.4 PPS (4.26 kg/sec).
2. Reset 86E, 86EA or 86EB as required.
3. Reset the Micronet from the ICE monitor.
4. Select starting fuel from the ICE monitor.
5. Select Manual Operating Mode.
6. Access the engine start button for engine A or B and initiate a normal single engine start from the ICE monitor.
7. First start attempt:
A. On the first start attempt the unit should be shutdown via emergency stop pushbutton as soon as light off is sensed (See ICE monitor screen)
NOTE
Shutdown should be initiated before NH reaches 4600 RPM.
8. Access the engine enclosure, check for oil leaks, fuel leaks, etc. Listen during engine run down for rubbing and strange sounds. Check oil level in tank. Note it should have dropped slightly during the starter checkout as oil flowed into the gas generator bearings.
Pratt and Whitney Power Systems, Inc.
Commissioning Manual - Revision 4 TEMPORARY REVISION NO. 07-02
Please insert this Temporary Revision in the Commissioning Manual Rev 4, Procedure 29 – Initial Light-Off, Power Turbine Start-up and Break-in, before page 29-3.
The tunable in step 11. has been corrected to read SD_UN _FC.NPFAILINH.IN.
CAUTION
Repeat steps for initial light off on a twin pac installation for the second engine. Do not proceed with the break in procedure until both GG's have achieved initial light off and are ready for further operation.
Figure 29 - 1
9. Select the "Scales" icon at the top of the main ICE screen and choose "PT Tests".
10. Select A or B engine for PT Break-Away Test, see Figure 29 - 1.
• Note that the NP overspeed set point is automatically set to 350 NP 11. Inhibit the NP failure shutdown, SD_UN _FC.NPFAILINH.IN.
12. Second start attempt:
CAUTION
Repeat steps for initial light off on a twin pac installation for the second engine. Do not proceed with the break in procedure until both GG's have achieved initial light off and are ready for further operation.
Figure 29 - 1
9. Select the "Scales" icon at the top of the main ICE screen and choose "PT Tests".
10. Select A or B engine for PT Break-Away Test, see Figure 29 - 1.
• Note that the NP overspeed set point is automatically set to 350 NP 11. Inhibit the NP failure shutdown, SD_UN_FC.NP_FAILURE A or B 12. Second start attempt:
A.
Repeat steps to start one engine.1)
On the second start attempt, allow the gas generator to accelerate toward idle until the power turbine starts to rotate. Monitor the free turbine shaft at the engine because the ICE Monitor and Tach may not record very low rpm. Check for unusual noises, leaks, etc. Allow the power turbine to accelerate and trip at 350 RPM via the Micronet overspeed.CAUTION
If the unit does not trip by 400 RPM, activate the emergency stop and resolve the problem before continuing.
B.
Inspect both engine enclosures, lube oil skids, generator enclosure, hydraulic start skid, etc. for leaks or abnormal conditions. Listen to the generator and power turbine rundowns.13. If the engine achieves GG idle (7800-8200 NH) without breaking away the PT, allow the engine to remain at idle speed for one minute then initiate a stop via the emergency stop pushbutton.
14. After the trip, reset the controls and prepare to restart as soon as possible. Enter an additional
"NH Idle Trim Value" of 800 RPM into the screen location using the blue arrow on the test screen in the predetermined values of +200, 400, 600, 800, followed by the "enter" key.
15. Repeat steps as in item 12.
16. If the PT breaks away, it will trip via NP overspeed at 350 NP RPM. If the PT does not break away, allow the engine to sit at this raised NH point for a maximum of one minute then stop by pressing the emergency stop pushbutton.
17. Inspect the equipment and repeat step 11 to break away this engine. This will be the third break away attempt. If the PT does not break away after the previous one minute at GG idle and one additional minute at GG idle plus 800 NH RPM, contact PWPS Customer Support Engineering for further instructions. DO NOT attempt to break away the opposite PT. If PWPS personnel are not available, allow the PT to cool for a minimum of 4 hours and repeat the procedure above.
NOTE
Do not attempt any running above idle unless the overspeeds have been set and tested as above.
18. Lockout the first engine and unlock the second engine.
19. Repeat steps 1 through 13 for the second engine.
WARNING
The following steps are to be completed by a responsible test person who will remain at the control panel at all times, within easy access of the emergency stop pushbutton.
All attempts should be made to continue this procedure before the PT stops rotating.
20. PT breakaway should be deselected by the engine trip. Select PT Break-In test from the screen in figure 1 for both engines. See Figure 29 - 2.
21. Initiate a twin pac start (Start Both).
22. Uninhibit SD_UN_FC.NP_FAILURE during the purge cycle.
23. Allow each GG to achieve stable GG idle, breakaway the generator and accelerate the rotor to a steady state RPM.
Figure 29 – 2
24. After the GG and NP speeds are at a steady state condition, inspect enclosures as required.
Note steady state NH and NP.
25. Manually accelerate the power turbine to 2100 NP at a rate less than 600 RPM/Minute. The times and NP speeds required for thrust balance seal break-in are provided in Table 29-1 below.
Hold the appropriate speeds, as shown in Table 29-1, for the required time to properly break-in the thrust balance seals.
CAUTION
For additional overspeed protection, the unit trip button must be manned at all times.
The NP speeds differ depending on configuration. Both 50-Hz and 60-Hz speeds are listed in Table 29-1.
60-Hz CONFIGURATION 50-Hz CONFIGURATION
Time In Minutes NP Time In Minutes NP
5 2100 (See Note Below) 5 2100 (See Note Below)
10 3000 10 2600 15 3600 15 3000 15 3950 15 3250 10 3600 10 3000 10 3000 10 2600
20 2100 (See Note Below) 20 2100 (See Note Below)
NOTE
2100 or minimum obtainable NP speed.
Table 29-1 Thrust Balance Seal Break-In
26. After the last dwell period at 2100 NP, initiate a stop by operating the emergency stop pushbutton.
27. Lockout both engines.
28. Observe GG, PT and generator coastdown. Note any abnormalities.
29. Record a Trend trace of NP speed during the break-in period.
30. Reset the tunables as required. Save tunables in the control.
31. Secure the unit as necessary.
32. Install tags on valves, breakers, switches, etc. as necessary.