ML022900452

Request for Additional Information (RAI) - Amendment Application Diesel Generator Allowed Outage Time

ML022900452
Person / Time
Site:	Nine Mile Point
Issue date:	10/07/2002
From:	Conway J Constellation Generation Group
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NMP1L 1692, TAC MB4612
Download: ML022900452 (18)

Text

P.O. Box 63 Lycoming, New York 13093 Constellation Generation Group Nine Mile Point Nuclear Station October 7, 2002 NMP1L 1692 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

SUBJECT:

Nine Mile Point Unit 1 Docket No. 50-220 Request for Additional Information (RAI) - Amendment Application Re: Diesel Generator Allowed Outage Time (TAC NO. MB4612)

Gentlemen:

By letter NMP 1L 1656, dated March 27,2002, Nine Mile Point Nuclear Station, LLC, (NMPNS) transmitted an application for amendment to the Nine Mile Point Unit 1 (NMP1) Technical Specifications (TSs). The proposed amendment would revise Specification 3.6.3.c to extend the allowed outage time (AOT) for an inoperable diesel generator (DG) from 7 days to 14 days.

On August 6, 2002, the NRC staff transmitted by e-mail a list of questions regarding the proposed TS amendment and requested a conference call with the NMPNS staff to discuss the issues. As requested, a telephone conference was held on August 9, 2002 between NRC and NMPNS staff representatives to discuss the questions and disposition the corresponding issues and responses. As a result of the telephone conference, the NRC staff issued a formal RAI on August 20, 2002, which included five questions. The attached information provides the NMPNS responses to the five questions.

I declare under penalty of perjury that the foregoing is true and correct. Executed on October 7, 2002.

Sincerely,

? ofConway Site Vice President JTC/CDM/jm

Page 2 NMPIL 1692 Attachments:

1. Response to Request for Additional Information

2. Woodward Governor Post-Repair/Replacement Testing Recommendations cc: Mr. H. J. Miller, NRC Regional Administrator, Region I Mr. G. K. Hunegs, NRC Senior Resident Inspector Mr. P. S. Tam, Senior Project Manager, NRR (2 copies)

Mr. John P. Spath, NYSERDA

ATTACHMENT 1 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION On August 9, 2002, the NRC staff held a telephone conference with the Nine Mile Point Nuclear Station, LLC, (NMPNS) staff to discuss previously e-mailed questions regarding the Technical Specification (TS) amendment request to extend the allowed outage time (AOT) for an inoperable diesel generator (DG). As a result of the telephone conference, the NRC staff issued a formal Request for Additional Information (RAI) on August 20, 2002, which included five questions. As requested, the following information provides the NMPNS responses to the questions. Note that for each of the five questions, the question is repeated verbatim (italics added) from the RAI, followed by the NMPNS response.

NRC Ouestion (1) Discuss the reasons and bases to extend the presentAOT for an inoperableEDG from 7 to 14 days.

NMPNS Response The reasons for the proposed extension of the DG AOT from 7 to 14 days are discussed in Attachment B, Section 1.2, of the TS amendment request submittal.

The proposed AOT extension would improve DG availability during refueling outages and avert unnecessary unplanned plant shutdowns, where there would be less impact on plant risk by continued operation. The 14-day duration of the AOT was judged to be necessary to accommodate planned DG inspections, maintenance, and overhauls. In particular, the proposed 14-day AOT would permit the required 2-year DG inspections and 6-year overhauls to be performed online and reduce the potential for requests for enforcement discretion needed to complete emergent DG repairs. The 2-year DG inspections typically require 2 to 3 days to complete, with the 6-year overhauls typically requiring 5 days to complete. Additional programmatic risk-management controls are invoked when planned Limiting Condition for Operation (LCO) entries could exceed 50 percent of the AOT. As a result, the 6-year DG overhauls and 2-year inspections are currently administratively restricted from performance online with the present 7 day AOT. In addition, the duration for unplanned repairs resulting from either the 2-year inspection or the 6-year overhaul could reasonably be expected to exceed the present 7-day AOT.

The bases for the proposed extension of the DG AOT from 7 to 14 days are discussed in Attachment B, Sections 2.1 through 2.3, of the TS amendment submittal. The 14-day duration of the AOT is based primarily on the Probabilistic Risk Assessment (PRA) discussed in Section 2.3, with the online risk-Page 1 of 6

management and Maintenance Rule programs providing assurance that the PRA assumptions remain valid. Furthermore, the proposed 14-day AOT maintains consistency with the defense-in-depth philosophy, and continues to comply with the Station Blackout (SBO) Rule (10 CFR 50.63) and the applicable General Design Criteria and Regulatory Guides (except for 72-hour AOT specified in Regulatory Guide 1.93) as required by the acceptance guidance provided in Regulatory Guide 1.177.

NRC Question (2) It is the NuclearRegulatory Commission (NRC) staffs understandingthat the purpose of the requestedamendment is to allow an increasedoutage time during plantpower operationfor performing EDG inspection, maintenance,and overhaul, which would include disassembly of the EDG. EDG operability verfi cation after a major maintenance or overhaul may requireafull-load rejection test. If a fidl-load rejection test is performed atpower,please address thefollowing:

a. What would be the typical and worse-case voltage transients on the 4160-V safety buses as a result of a full-load-rejection?

b. If a full-load rejection test is used to test the EDG governor after maintenance, what assurancewould there be that an unsafe transient condition on the safety bus (i.e., load swing or voltage transient)due to improperlyperformed maintenance or repairof a governor would not occur?

c. Using maintenanceand testing experience on the EDG, identify possible transientconditions caused by improperlyperformed maintenanceon the EDG governor and voltage regulator. Discuss the electricalsystem response to these transients.

d. Provide the tests to be performed after the overhaul to declarethe EDG operable andprovidejustification ofperforming those tests atpower.

NMPNS Response The NMP1 TSs do not require periodic performance of a DG full load rejection test as is required by the standard TSs for Boiling Water Reactors (NUREG-1433 and NUREG-1434). Furthermore, as discussed in the August 9, 2002 conference call with the NRC staff, the DG governor manufacturer, Woodward Governor Co., does not provide any recommendations suggesting that a full load rejection test would be necessary following the repair or replacement of a governor. As requested by the NRC staff, the governor manufacturer's testing recommendations are provided for information as Attachment 2.

Page 2 of 6

NRC Question (3) What type of communication has been established between the control room operatorofNMP1 and the System Load Dispatcher? Will the System Load Dispatcherbe notified in advance that the EDG is going to be outfor an extended period of time?

NMPNS Response Communication with the Niagara Mohawk system load dispatcher is controlled by procedures S-ODP-OPS-0112 and GAP-PSH-03. Communication with the system load dispatcher is accomplished either by a written work authorization request for routine scheduling of work activities affecting the offsite power system, or by a dedicated telephone line for verbal notifications and the coordination and planning of emergent work activities.

Existing procedural controls would require notification of the system load dispatcher for planned or emergent entries into the TS LCO for an inoperable DG when it is necessary to protect the available offsite power sources. Attachment B, Sections 2.2.1 and 2.3.5, of the TS amendment request identifies the compensatory measures required for entry into the proposed extended DG AOT (greater than 7 days and up to 14 days). Implementation of the compensatory measure controlling elective testing and maintenance activities affecting the offsite power system (identified as second bullet in TS amendment request) will address notification of the system load dispatcher prior to entry into the extended DG AOT since the offsite power sources will be required to be protected.

NRC Question (4) It is the NRC staffs practice to approve an EDG AOT extension for those licensees who have either installedan alternateAC source that can be substituted for an inoperable EDG, or have excess power capacityfrom the existing EDGs supplied through bus cross-ties that can be temporarilyused to compensatefor an EDG in an extended AOT. Please indicate if you have an extra power source that can be used in this capacity.

NMPNS Response NMP1 does not have an extra power source that can be substituted or cross-tied to compensate for an inoperable DG. However, based on the discussion in Attachment B, Section 2.2.1, of the TS amendment request, and as further discussed below, NMPNS believes that adequate defense-in-depth is achieved without an extra power source due to the passive safety system design of the NMP1 Emergency Cooling System (ECS). Consistent with Regulatory Guide 1.177, the ECS and diesel driven fire pump (DFP), when considered in combination, maintain consistency with the defense-in-depth philosophy by Page 3 of 6

preserving a reasonable balance among prevention of core damage, prevention of containment failure, and consequence mitigation without the need of an extra power source. The ECS and DFP are described in detail in the NMPI Updated Final Safety Analysis Report (UFSAR), Sections I.A.3, V.A - C and E, VIII.A and C, IX.B.6, X (Appendix 10B, Section 5), and XV.B and C.

NMP1 is a General Electric BWR/2 product line Boiling Water Reactor (BWR) and, unlike later BWR plant designs, there are no High Pressure Core Spray (IIPCS), Reactor Core Isolation Cooling (RCIC), or Residual Heat Removal (RHR) Systems. In addition, the NMP1 design uses dedicated Core Spray, Containment Spray, and Shutdown Cooling Systems to perform the comparable functions of the low pressure core spray (LPCS), containment/suppression pool spray, suppression pool cooling, and shutdown cooling modes of a typical RHR System NMP1 does not have a system or required function comparable to the Low Pressure Coolant Injection (LPCI) mode of the RHR System. Also, in contrast to later BWRs with single train High Pressure Coolant Injection (HPCI)

Systems using a single steam driven turbine pump, the HPCI System at NMIP1 is an operating mode of the Condensate and Feedwater Systems using redundant motor driven pumps. At NNMP1, the HPCI System is not a safeguards system, nor is it credited in any loss of coolant accident (LOCA) analyses.

The NMP1 ECS, in conjunction with the Automatic Depressurization System (ADS) and Core Spray System, perform the comparable functions of the HPCS/HPCI, RCIC, ADS, and RHR (LPCS mode) Systems of later design BWR plants. The aforementioned NMP1 systems are described in the NMP1 UFSAR, Sections V.E, VII.A, B, and I, and X.A.

The ECS is credited for fission product decay heat removal without the loss of reactor water inventory following a reactor scram when the main condenser is not available as a heat sink, or in the event of a loss of reactor feedwater. The ECS is also capable of decay heat removal during a LOCA to aid in reactor depressurization and core cooling. In addition, the ECS is credited for the Anticipated Transient Without Scram event to aid in heat removal and to help maintain vessel inventory, and is relied upon as the principal means to bring the plant to a hot shutdown condition under such unanticipated occurrences as SBO and a 10 CFR 50, Appendix R, event.

The ECS consists of two independent loops, each with two emergency condensers, and operates by natural circulation, without the need for electrical power. The system is initiated manually or automatically on high reactor pressure, if the high-pressure persists for 12 seconds, or on low-low reactor water level, after a 12-second time delay. In the event of an isolation of the reactor from the main condenser, the emergency condensers of the ECS will condense the steam generated by decay heat and limit the reactor pressure rise, thereby limiting the loss of reactor water inventory which may occur through the opening of the ADS electromatic relief valves (ERVs). Similarly, by removing decay heat Page 4 of 6

following a loss of feedwater event, the ECS will reduce reactor pressure below the ADS ERV setpoint, thereby limiting the amount of water loss and assuring core coverage and cooling. As discussed in Question 5 below, the DFP is capable of providing reactor vessel makeup when necessary.

The later design BWR plants requiring a HPCS System also require an additional onsite emergency AC power source (typically a DG) to operate the HPCS pump for the performance of credited safety functions. A primary safety function of HPCS is serving as a backup to the RCIC System to assure reactor depressurization and decay heat removal following a reactor vessel isolation accompanied by a loss of reactor feedwater. The RCIC pump is steam driven and does not require electrical power. However, since RCIC is only a single train system, HPCS (which requires electrical power to operate its pump) is required as a backup. As described above, the NMP1 ECS does not require electrical power for operation, and it performs reactor depressurization and decay heat removal functions that are comparable to RCIC. However, in contrast to RCIC, the NMP 1 ECS consists of redundant trains, with each train being independently capable of satisfying the credited decay heat removal safety functions. Accordingly, the NMP 1 ECS is considered much more reliable than the single train RCIC System and does not require a backup system such as HPCS. Moreover, in contrast to later BWR plant designs, NMP1 does not credit an additional system, such as HPCS, to assure core cooling following a small break LOCA. Thus, no additional AC power source is required for the mitigation of a small break LOCA at NMP1.

Note that the ECS (which does not require electrical power for operation) would be effective in assisting the ADS in depressurizing the reactor vessel for small line breaks, but is not required for this event. Also note that the NMP 1 HPCI System, although not an engineered safeguards system, would provide core cooling following a small break LOCA if offsite power is available.

For plants with a HPCI System in lieu of HPCS, the LPCI and RCIC Systems are required backup systems, in addition to the ADS and Core Spray System. As previously discussed, NMP1 does not require either a LPCI System or a RCIC System in addition to the ADS and Core Spray System, and does not credit the HPCI System in any LOCA analyses.

In summary, NMP1 is a BWR/2 plant design, which is capable of satisfying all required design basis and functional requirements without a HPCS/HPCI System and the associated additional AC power source requirements. NMPI credits the passive safety system design of the ECS (operates by natural circulation) and a DFP for required license basis functions, including safe shutdown for SBO and 10 CFR 50, Appendix R, events. Therefore, adequate defense-in-depth is maintained during the proposed extended DG AOT with operability of the NMP1 ECS and a DFP. NMP1 TS 3.1.3 assures operability of the ECS during power operating conditions and whenever the reactor coolant temperature is greater than 2120 F, except for hydrostatic testing with the reactor not critical. As committed in Attachment B, Sections 2.2.1 and 2.3.5, of the TS amendment submittal, the Page 5 of 6

NMP1 DFP and the NMP2 DFP and cross-tie to NMP1 will be operable for reactor vessel makeup when entering the proposed extended DG AOT.

NRC Ouestion (5) You stated thatfire pumps can be used to deliver water as afeedwater make-up source to the reactorvessel. Pleasediscuss in detail, how this will be accomplished.

NMPNS Response Specific direction regarding the connection and use of the DFPs for reactor vessel makeup currently exists in the NMP1 Emergency Operating Procedure N1-EOP-1 and Special Operating Procedures NI-SOP-18 and N1-SOP-20. As applicable, these procedures provide the necessary instructions to install the dedicated spoolpiece to intertie the required feedwater and fire system lines for reactor vessel injection using either the NMP1 or NMP2 DFP. Additional details regarding the crediting of this action for SBO and 10 CFR 50, Appendix R, are available in the NMP1 UFSAR, Sections IX.B.6.2 and X (Appendix 1OB, Sections 5.4 and 5.6).

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ATTACHMENT 2 WOODWARD GOVERNOR POST-REPAIR/REPLACEMENT TESTING RECOMMENDATIONS

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"* TYrPE UG-8 UG DIAL GOVERNOR WOODWARD GOVERNOR COMPANY MANUAL 03040D

TABLE OF CONTENTS Adjustments ............................... 15 SECTION 1 15 Compensation Adjustments ................

GENERAL INFORMATION_.................... 1 1 Initial Operation for a Repaired or Introduction ...........................

Reassembled Governor ...................... 16 Description ................................... 2 18 Test Procedures .............................

References ................................... 20 Test Completion .............................

SECTION 2 INSTALLATION PROCEDURES ............... 4 SECTION 5 Introduction .................................. 4 TROUBLESHOOTING ....................... 21 Receiving .................................... 4 Introduction ................................. 21 Storage ...................................... 4 Troubleshooting ............................. 21 Mounting Requirements ....................... 4 O il ........................................ 21 Linkage Attachments ......................... 5 Compensating Adjustment and O il Supply .................................... 6 Needle Valve .............................. 21 Definitions ................................ 21 SECTION 3 Preliminary Inspection ..................... 22 PRINCIPLES OF OPERATION ................. 9 23-27 Troubleshooting Chart ....................

Introduction .................................. 9 Additional Information for Steam Component Description ....................... 9 28 Turbines, Gas and Gasoline Engines ..........

O il Pum p ................................... 9 28 Governor Field Repairs ...................

Accumulator ............................... 9 Removal of Governor from Engine .......... 28 Power Piston ............................... 9 Pilot Valve System .......................... 9 SECTION 6 Ballhead System ........................... 11 31 11 REPLACEMENT PARTS .....................

Compensation System ..................... Replacement Parts Information ............... 31 Load Limit Control ........................ 12 Illustrated Parts Breakdown ............... 32-41 Synchronizer ............................. 12 Speed Droop ............................. 12 SECTION 7 Operation of the UG Dial Governor ........... 13 AUXILIARY EQUIPMENT .................... 42 General Information ....................... 13 Introduction ................................. 42 Decrease in Load .......................... 13 14 Synchronizer Motor and Solenoid Increase in Load ........................... Shutdown ................................... 42 Bodine Synchronizer Motor ................ 42 SECTION 4 PM Synchronizer Motor with Housing ....... 43 GOVERNOR OPERATION AND 15 Low Lube Oil Pressure Shutdown ............. 44 ADJUSTMENTS ............................. 44 15 Magnetic Speed Pickup ......................

Introduction ................................. 44 15 Micro Switches and Wiring Harness ...........

Initial Operation for a New Governor ..........

LIST OF ILLUSTRATIONS UG8 Dial Governor ....................... ii 7-1 UG Cover with Bodine Motor and Shutdown Solenoid ..................... 42 1-1 Recommended Output Shaft Travel 1 7-2 Installing Cover with Bodine Adjustment ..............................

3 Synchronizer Motor ..................... 42 1-2 Outline Drawing of UG Dial Governor .....

7-3 UG8 Dial Governor Equipped with Bodine 2-1 Linkage Arrangement (For Non-Linear Synchronizer Motor ..................... 43 Fuel System) ............................ 5 7-4 Top View of Weatherproof Housing with 3-1 Schematic Diagram of the UG Dial PM Synchronizer Motor and ShutdoWn Governor ............................... 10 Solenoid ............................... 43 4-1 Maximum and/or Minimum Speed Stop 7-5 UG8 Governor with PM Motor, Weather Adjustment on the UG Dial Governor ...... 19 proof Housing .......................... 43 5-1 Common Bench Tools .................. 29 7-6 Low Lube Oil Pressure Shutdown ........ 44 5-2 Normal Field Repair Tools ............... 30 7-7 Magnetic Speed Pickup ................. 44 6-1 Parts Illustrations for the UG Dial 7-8 Micro Switches and Wiring .............. 45 33-41 7-9 Wiring Harness on Cover ................ 45 Governor ............................

i

OIL FILLER CAP COVER "OIL SIGHT GLAS*S f

OUTPUT SHAFT (TERMINAL SHAFT)

DIAL PANEL--

COMPENSATION POINTER CASE COMPENSATION NEEDLE VALVE PLUG OIL DRAIN PLUG 03000-A-1 S0 UG8 Dial Governor II

wY SECTION 4 GOVERNOR OPERATION AND ADJUSTMENTS INTRODUCTION adjusting compensation to obtain satisfactory stability and response. All other operating adjustments were made during factory calibration in This section describes initial operation and basic accordance with the manufacturer's specifications adjustments of the UG Dial for putting a new or and should not require further adjustments.

repaired governor into service.

INITIAL OPERATION NOTE FOR A NEW GOVERNOR Do not attempt internaladjustment of the Before initial operation of the UG Dial Governor, governor unless you are thoroughly check that all previous installation steps have been familiar with the properprocedures.

correctly accomplished and all linkages are secure and properly attached. See Section 2, Installation Procedures. Also, read all of Section 4.

COMPENSATION ADJUSTMENTS Fill the governor with oil to the top mark on the oil The compensation needle valve and pointer are sight glass. Close the needle valve carefully (cw) adjustable parts of the compensation system. Their using a Phillips screwdriver and open it (ccw) 1/2to settings directly affect governor stability.

3/4 turn. Loosen the nut holding the compensation adjusting pointer enough to move the pointer and Compensation must be properly adjusted to the set the pointer in the center of the scale. Tighten the nut. particular engine and load to provide stable operation.

If replacing a governor, the initial compensation When the engine, turbine or other type of prime setting can be that of the governor just removed.

mover is started for the first time after the governor has been filled with oil, the governor may be stable at constant speed, yet the governor may need adjustment. High overspeeds and underspeeds after load changes and slow return to normal speed TO PROTECT AGAINST POSSIBLE indicate the need for compensation adjustment.

PERSONAL INJURY, LOSS OF LIFE AND/OR PROPERTY DAMAGE WHEN STARTING the engine, turbine or other NOTE type of prime mover BE PREPARED TO MAKE AN EMERGENCY SHUTDOWN to Maximum compensation settings protect against runaway or over-speeding should the mechanical-hydraulic generally provide stable steady state governor(s) or electric control(s), the operation,but result in greateroffspeeds actuator(s), fuel control(s), the driving on load changes.

mechanism(s), the linkage(s), or the controlled device(s) fall. After the oil in the governor has reached its normal operating temperature, M~ake the following compensation adjustments without load on the Use the prime mover manufacturer's instructions to start the engine. prime mover to be certain that the governor gives optimum control. See figure 1-1 for location of the ADJUSTMENTS adjustment parts.

Normally, the only adjustments for putting a new 1. To bleed trapped air from the governor oil governor into service are bleeding entrapped airand passages, first loosen the nut holding the 15

WAP compensation adjusting pointer and set the by turning the load limit knob to increase the pointer at its extreme upward position for load slightly and bringing it back quickly to+.e maximum compensation. Tighten nut. original position. Gradually close the needle valve until governor returns to speed with only Next, remove the needle valve access plug and a small overshoot or undershoot and:

open the needle valve two turns ccw. Use a Phillips screwdriver to avoid damage to the a. The needle valve is between 1/8 to 1/4 threads inside the bore and to the needle valve. turn open on a governor with an oil sight glass located in the center of the dial Damage to the threads or to the needle valve panel.

will cause the governor to change fuel rhyth mically. This is called governor hunt. See b. The needle valve is between 3/8 and 3/4 Section 5 for more information on hunting. turn open on a governor with an oil sight glass located on the side of the governor.

There are two screwdriver slots in the needle valve, a shallow and a deep slot, located at right Compensation adjustment determines offspeed and angles to each other. The deeperslot is used to needle valve adjustment determines recovery time expand the head of the needle valve and increase friction to prevent vibrations from changing the needle valve setting. If a plain NOTE screwdriver must be used, be sure to use the shallow slot of the needle valve. For most responsive governor control, use as little compensation as possible.

Allow the prime mover to hunt for approxi- Too much compensationcauses excessive mately one-half minute to bleed trapped air speed overshoots and undershoots upon from the governor oil passages. load changes.

2. Loosen nut holding the compensation pointer and set the pointer as far as it will go towards NOTE minimum compensation. Tighten nut.

Closing the needle valve more than indi

3. Gradually close the needle valve until hunting catedin a. and b. above makes the governor just stops. If hunting does not stop, open the slow to return to normalspeed after a load needle valve one turn and move the compensa change.

tion pointer up by one mark on the front panel indicator scale. Again gradually close the needle Opening the needle valve more than valve until hunting stops. indicatedabove decreasesgovernorstabi lity and can cause hunting.

If hunting does not stop, set needle valve 1/4 turn open and repeat setting the compensation Once the needle valve adjustment is correct, it is not pointer up by one mark. Retest governor until necessary to change the setting except for large, hunting stops. permanent changes in temperature which affect governor oil viscosity.

NOTE When the compensation adjustment is correct, The objective of the compensation tighten the compensation pointer nut and install the adjustment procedure is to find the needle valve access plug with a copper washer. The particularsettingsfor the compensa plug and the washerwill seal oil seepage around the tion needle valve and compensation needle valve.

adjustment pointer at which the engine, turbineor othertype of prime mover, will return quickly to speed INITIAL OPERATION FOR A REPAIRED (needle valve adjustment) after a OR REASSEMBLED GOVERNOR speed disturbancewith only a slight over or undershoot (compensation After disassembly or repair, it is very important to pointer adjustment). test the governor on a test stand. If a test stand is not available, testing of the governor can be done on t

4. From this setting, open the needle valve one turn and momentarily disturb governorstability engine.

16

• . OODWAPL)

Before installation be sure speed droop is not negative. To check droop, first set the speed droop control knob to zero.

If testing of the governor is done on the 1. Put a dial indicator (tool 8995-037) on the engine, the operator must be careful to governor with the indicator rod touching the manually control the engine speed until top of the speed setting gear.

he has proven that the governor will control engine speed.

2. Place the serration wrench on the governor Attach a serration wrench to the output output shaft.

shaft in addition to the normal linkage to manually control engine speed with the 3. Rotate the governor output shaft from serration wrench. minimum to maximum fuel position, and check the dial indicator.

When satisfied that the governing system is fully operative, remove serration wrench. 4. No movement of the indicator is zero droop. If movement is greater that .002 in, adjustment is needed (Cw movement of the indicator is If accurate tests and adjustments are to be made.

it is.best to use a test stand since it is difficult to positive droop. Ccw movement of the indicator make them when the governor is mounted on an is negative droop).

engine. Write or phone the Woodward Governor Company for a test specification for the governor Loosen the locknut (190) on speed droop screw part number shown on the nameplate fastened to (189) and turn the screwccw to reduce droop. Turn the governor.

the screw cw to increase droop.

Table 4-1 is a list of tools that are necessary only if a large number of governors is being tested. For a When zero droop is obtained (.002 in or lessccw small number of governors, only the pressure movement), tighten the locknut again (190).

gauge is needed to check oil pressure during testing.

Check again the adjustment by moving the governor Table 4-1. Test Stand Tools output shaft from minimum to maximum fuel position. Droop can be zero or positive, it must not be negative. Check the final droop setting with the Tool Woodward Application governor operating on the prime mover as shown in Description Number "Test Procedures" in this Section.

Woodward Engine Simulator. Drives Before operating a repaired governor for the first Test Stand Governor. Supplies time, check that all installation steps have been pressure oil. Includes correctly completed. See. Section 2. Installation gauges for testing. Procedures. Also, read all of Section 4.

Electronic Indicates governor drive Counter and speed. Must have an Frequency output of at least 60 Pickup cycles per revolution, on TO PROTECT AGAINST POSSIBLE a one second time base. PERSONAL INJURY, LOSS OF LIFE Must indicate speed to AND/OR PROPERTY DAMAGE WHEN within +/- 1 rpm. Readouts STARTING the engine, turbine or other of display time must not type of prime mover BE PREPARED TO exceed 5 seconds. MAKE AN EMERGENCY SHUTDOWN to protect against runaway or Pressure To check governor oil overspeeding should the mechanical Gauge pressure. hydraulic governor(s) or electric (0 to 200 psi) control(s), the actuator(s), fuel control(s), the driving mechanism(s),

Dial 8995-037 To check and adjust the linkage(s), or the controlled Indicator droop setting. device(s) fail.

MAtJVAL 0304OD 17

WooowAn TEST PROCEDURES If the engine cannot be run at full load and it isto be run at partial load only, the rpm decrease

1. Remove pipe plug (33) in the base of the must be proportional to the partial load.

governor on the side to the left of the needle valve plug (30), and attach a 0-200 psi pressure 10. If adjustment is needed to obtain zero droop, gauge. (See Figure 1-2 for Pressure Test Point.) follow this procedure:

2. Install governoron ateststand oron the engine Loosen the locknut (190) on speed droop pad. See Section 2, Installation Procedures.

screw (189) and turn the screw (189) ccw to reduce droop. Turn the screw cw to increase

3. Fill the governor with oil. See Section 2, Oil droop. Tighten the locknut.

Supply. The oil level must be to the mark on the oil sight glass.

Repeat the above procedure until speed is

4. If the governoris tested on the engine, start the within 0 to 3 rpm lower when running the prime moveraccording to the instructions from engine from no load to full load positions.

the manufacturer.

11. To prevent speed setting changes because of Run the governor until it is at operating engine vibrations, a friction drive (255) is temperature. installed in the speed setting mechanical drive of the UG Governor.

5. Check that the governor has a 110-120 psi oil pressure at normal operating speed. The friction drive (255) must be tight enough to avoid a speed setting change due to vibrations,

6. Close the needle valve (32) and open it just and also tight enough to permit the speed enough to cause a small hunt, using a Phillips setting motor, if used, to turn the speed setting screwdriver. If a plain screwdriver must be gear.

used, make sure to use only the shallow slot of the needle valveto avoid damage to the threads If the friction drive is too tight, the synchronizer inside the bore and to the needle valve. (speed setting) knob can no longer be turned manually.

Let the prime mover hunt for approximately one half minute to remove trapped air from the To adjust the friction on the friction drive, first governor oil passages. remove the governor cover (214). then the retaining ring (250) on the friction drive using a

7. Close needle valve anid open it again one half No. 1 Truarc pliers. Do not let the cover (214) or turn. If governor continues to hunt, repeat step the spring (252) fall into the governor as the

6. friction drive coveris under spring compression.

8. Adjust the compensation system. See Compen Place a torque wrench in the slots in top of the jRFv sation Adjustments in this Section. friction drive case (255) and check the torque oft 2 the friction drive and set it at 1 1/2-to 2 1/2 lb.in.with manual speed setting orfttjto 51/2lb.in. with speed jPV' NOTE setting motor. To increase friction, turn the nut of the shaft cw while holding the speed setting knob.

Maximum speed for constant operation To decrease friction, turn the nut ccw.

for the UG Dial Governoris 1500 rpm.

12. Reassemble the friction drive.

9. While the engine is running, re-check the governor for zero droop. Turn speed droop 13. Set the maximum and/or minimum speed limit knob to zero and run the governor-at normal on the governor. This adjustment can also be operating speed near0% load. Then load engine made with the prime mover running. To make near 100% load. Speed must be within 0 to 3 the adjustment, first remove the governor,-dial rpm lower. plate (see figure 4-1).

18

Turn the synchronizer (speed setting) knob cw governor up to its maximum-speed stop and to increase the speed setting of the governor down to its minimum speed. Reset torque on the from its specifie~d maximum plus 10 rpm. I friction drive, if necessary as in 11 above.

On governors equipped with a two-position high If the friction drive slips before reaching the speed stop (overspeed test device), set the required high speed setting, mark the inter overspeed-test speed as described above, then mediate (278) and the synchronizer (269) (speed the lever catch will provide the normal high setting) indicator gears, disengage synchronizer speed stop for the governor. If necessary set (speed setting) gear (269), index it one tooth the high-speed stop to the lever engaged posi ccwto allow a higher speed setting and engage. tion and then disengage the lever and advance gear again. to the normal high-speed stop position to achieve the overspeed-test speed.

14. To set the minimum speed limit, turn the synchronizer (speed setting knob) ccw to decrease the speed setting of the governor to its minimum speed position.

15. Set the synchronizer knob at zero on the dial.

(269) 16. Set the synchronizer indicator dial panel pointer at zero.

17. Position the synchronizer indicator knob about 1/16" from the surface of the dial. This prevents the knob from binding the synchronizer system gear train.

18. On governors equipped with micro switches, operate the governor at the required high and low speeds to verify correct positioning of the cams that operate the micro/switches.

Adjust the cams by loosening the screws and turning the cams on the shaft. Tighten screws again.

Figure 4-1. Maximum and/or Minimum Spe ed 19 On governors equipped with solenoid Stop Adjustment On The UG Dial shutdown, please refer to Woodward Governor Governor Company manual 03013 for set-up procedures.

20. Turn the load limit knob to zero. The load The amount of rpm change is not the same ifthe limit indicator must move to zero. The speeder screw (177) has a coarse thread (18 governor output shaft will move to its threads/inch) or a fine thread (32 threadslinch). minimum fuel position. Reset the load limit knob to maximum load.

Engage again the synchronizer indicator gear (269) with the high-speed stop pin, engaging the 21. Shut down the engine. Remove the pressure intermediate gear (278) to prevent further in gauge and install a 1/8" socket pipe plug.

crease in speed. The high-speed stop pin is the Apply a pipe sealer to the threads, and torque pin closest to the gear center. pipe plug down to 90 lb-in.

On governors equipped with an electric speed 22. Install the governor cover and dial plate.

adjusting motor, be sure the motor can run the 19

-OWP TEST COMPLETION When two units are set up for optimum single wLmt performance, paralleling problems can be encoun For operation of units running alone, set droop at-. .tered. For example, governor response can be too zero. Reducing droop to zero allows the unit to fast on one governor, requiring too high a speed change load without changing speed (zero droop droop setting to prevent a constant load interchange operation is also called isochronous operation). between the two governors. When this occurs, the compensation setting should be moved towards On units connected in parallel orto a single shaft, set maximum, reducing the single unit transient per the least amount of droop possible to provide formance capability but allowing stable parallel satisfactory load division. Droop allows load division operation within the allowable speed droop range.

between two or more prime movers that drive the Also, check amount of output shaft travel on each same shaft or are paralleled in an electrical system. governor (see NOTE, p. 12). Too little output shaft travel on a governor can require too high a droop For ac generating units tied in with other units, set setting on that governor to obtain steady state droop sufficiently high (reference number 30 to 50 control.

or more on the dial) to prevent interchange of load between units.

When UG governors are used on generator sets If one unit in the system has enough generating operating in parallel and the lead unit is shifted to capacity, set its governor on zero droop, and it will slave and vice versa, zero droop must be set on the regulate the frequency of the prime mover system. If lead unit to maintain the frequency for which it is set, its capacity is not exceeded, this unit will handle all and droop must be set on the slave unit for load load changes. distribution between the two units.

Operate the SYNCHRONIZER of the governor with For more information on load sharing, please refer zero droop to adjust the system's frequency. Operate to manual 25031, the Control of Prime Mover Speed, the SYNCHRONIZERS of the governors that have speed droop to distribute load between units. Part III, Parallel Operation of Alternators.

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