of Westinghouse DB Volt Circuit Breakers · Identify weight on form. 2) Energize the undervoltage coil with 48 VDC and manually close the breaker. ... 6 2/pol e 6 2/pol e 8 5 Left/3

PGandE Letter No.: DCL-85-151

Attachment 5

Diablo Canyon Power Plant

Maintenance Procedure E-51.7

"Maintenance of Westinghouse Type DB 480 Volt Circuit Breakers"

85042403bb 850418PDR ADOCK 05000275P PDR

0281S/0031K

Attachment 5

W~(3 <~M Pacific Gas and Electric Company

DEPARTMENT OF NUCLEAR PLANT OPERATIONS

DIABLOCANYONPOWERPLANT UNIT NO(S) 1 AND 2ELECTRICAL MAINTENANCE PROCEDUREMAINTENANCE OF WESTINGHOUSE TYPE DB

TITLE: 480 VOLT CIRCUIT BREAKERS

APPROVED:PLANT MANAGER

NUMBER MP E-51. 7

REVISION 6

DATE 4/11/85PAGE 1 OF 13

)MP~3I-")"'.y''3T

li~ a+ r

C

DATE

SCOPE

This procedure establishes the method and requirements for routineinspection and maintenance of Westinghouse Electric Corp. Type DB-50Air Circuit Breakers.

This procedure and changes thereto require PSRC review.

PREREQUI S ITES

1. Obtain and check clearance on breaker to be serviced.

2. Establish Housekeeping Zone 4 per Administrative Procedure C-10.

3. When in Modes 1 and 2, prior to performing this procedure on thereactor trip breakers a spare breaker will'e serviced inaccordance with the requirements defined in this procedure.

a. Remove the reactor trip breaker and replace with sparebreaker.

4. Obtain the following calibrated instruments, as applicable.

a. 20 oz. weight + 0 oz - 4 oz.

b. Spring force scale or force gauge with an accuracy of atleast + 1.0 oz. (Chatillon DPP32)

c. Voltmeter with an accuracy of at least +0.5% full scale,using the 0-200 or 0-100 volt scale.

d. Timer with an accuracy of at least +10 milliseconds.

5. Standard thickness gauges or standard size bar stock may be usedto determine gaps and clearances.

DC0128 1X I V

DIABLO CANYON POWER PLANT UNIT NO(S) 1 AND 2NUMBER MP E-51. 7

REVISION 6DATE 4/11/85.PAGE 2 OF 13

TITLE:MAINTENANCE OF WESTINGHOUSE TYPE DB

480 VOLT CIRCUIT BREAKERS

6. Review previous maintenance data for breaker.

7. Remove breaker.

8. Obtain forms 69-10647 and 69-9546 as applicable.

PRECAUTIONS AND LIMITATIONS

1. The reactor trip breakers are part of the "Reactor Trip SystemInstrumentation" and Technical Specification 3/4.3. 1 applies.

2. When the breaker is charged, keep fingers and hands away frommain and arcing contacts and operating mechanism.

3. The undervoltage trip attachment (UVTA) may be restrained byeither applying 48 VDC to the coil or manually restraining thereset lever with a cord or spring.

4. Adjustments to the reactor trip and bypass breakers beyond thosespecified in the procedure are not authorized without furtherapproval.

a. Contact Electrical Maintenance Engineering for technicalguidance.

PROCEDURE

1. As-Found Conditions

a. Trip Force

1) Restrain the undervoltage trip coil and manually closethe breaker, if applicable.

2) Check the trip force by pushing or pulling (per Fig. 3)vertically on the trip bar. Record the force in ouncesat the instant of breaker trip.

b. Undervoltage trip verification, reactor trip and bypassbreakers only.

1) Load the trip bar (per Fig. 3) with the 20 oz. weight.Identify weight on form.

2) Energize the undervoltage coil with 48 VDC and manuallyclose the breaker.

0C0128 2XIV

DIABLO CANYON POWER PLANT UNIT NO(S) 1 AND 2NUMBER MP E-51.7REVISION 6DATE 4/ 1 1/85PAGE 3 OF 13



c ~

3) Reduce voltage to within ~5 volts of last recordeddropout voltage.

4) Decrease voltage slowly (15 sec/volt) until the breakertrips. Record voltage.

5) Repeat the test twice and average the three readings.Record average voltage.

Shunt Trip Verification

1) Restrain the undervoltage trip attachment, ifapplicable.

2) Manually close the breaker.

3)

4)

Connect an adj ustable (0-120 VDC) DC voltage source tothe shurt trip" coil.

Increase voltage to within ~5 volts of last recordedpickup voltage.

d.

5) Increase voltage slowly (15 sec/volt) until the breakertrips. Record voltage.

6) Repeat the test twice and average the three readings.Record average voltage.

7) Remove mechanical UVTA restraining device if used andweight on trip bar.

Breaker Response Time Verification - UVTA (Reactor Trip andBypass Only)

1) Connect timer to the breaker (see Figure 4).

2) Energize the undervoltage coil with 48 VDC and manuallyclose the breaker.

3) Trip breaker and start timer with control switch.Record time in milliseconds.

4) Repeat the test twice and average the three readings.Record average time.

DC0128 3XIV

DIABLO CANYON POWER PLANT UNIT NO(S) 1 AND 2NUMBER MP E-51.7REVISION 6DATE 4/11/85PAGE 4 OF 13



e. Breaker Response Time Verification - Shunt Trip (ReactorTrip and Bypass Only)

1) Connect timer to the breaker (see Figure 5).

2) Restrain the undervoltage trip coil and manually closethe breaker.

3) Trip breaker and start timer with control switch.Record time in milliseconds.

4) Repeat the test twice and average the three readings.Record average time.

5) . Remove voltage sources, etc.

2. Dismantle the breaker to the extent necessary to perform thefollowing, as applicable. Document on Form 69-10647. Anyrejectable conditions should be identified in the remarkssection.

3. Clean the entire unit by wiping with paper towels or lint-freecloths to remove dust and dirt. Brushing with a medium or stiffbristle brush may be necessary. Do not use a wire brush or highpressure air. Brushing may be supplemented by vacuuming.

a. Verify that the following retaining rings are securely inplace on all visible shafts and pins. Record the number ofretaining rings as found and as left.

~TY

1) Moving Contact Hinge Pins

2) Stationary Arcing ContactHinge Pins

3) Cross-bar

,4) Operating Mechani smHinge Pins

5) Auxiliary Switch Linkage

6) Pantograph

7) Positioning andInterlock Level

6 2/pol e

6 2/pol e

8 5 Left/3 Right

6 3 Top/3 Bottom

DC0128 4XIV

DIABLO CANYON POWER PLANT UNIT NO(S) 1 AND 2NUMBER MP E-51. 7REVISION 6DATE 4/11/85PAGE 5 OF 13



4,

b. Check all the hinge pins and slides for wear.

c. Check the pole bases for cleanliness and cracks.

d. Check all visible bolts and nuts for tightness.

e. Check insulation link (Ref. Fig. 1) for cleanliness, chips,cracks, and tightness of locknut.

f. Check condition of wire insulation and terminations.

Check contact pressure by verifying (or adjusting) gap "G" (referFig. 1) to 0.050 - 0.093 inches. This gap is adjusted byremoving the cross-bar and screwing the insulating link in or outon the stud. Assure that arcing contacts (relative to maincontacts) make first in closing and break last in opening.

a. Tighten the locknuts after each adjustment.

b. Check for over-adjustment by prying the stationary arc tipsopen to at least 1/16 inch gap.

c ~ Check main and arcing contacts for evidence of overheating,burning, and pitting.

1) Contacts may be dressed using a light file to removerough projections and burrs or sprawls, left by arcing.Such removals should be limited to those conditionswhich would interfere with the proper seating or wipingof the contact surfaces. Take the appropriate steps toprevent filings from co'ntaminating the mechanism orinsulation parts.

2) Do not remove the oxide or sulfide film. These filmsare easily penetrated to provide low resistance pathsby contact pressure and wipe.

a) To replace the arcing contacts, open the breaker,remove the arc chutes and then the stationaryarcing contacts.

b) Close the breaker and remove the moving arcingcontacts.

DC0128 5X I V

DIABLO CANYON POWER PLANT UNIT NO(S) 1 AND 2NUMBER M ) E-51 7REVISION 6DATE 4/11/85PAGE 6 OF 13

MAINTENANCE OF WESTINGHOUSE TYPE DB


c) The new contacts can then be added in the reverseorder.

'5. Check main contact clusters and retainers for cracks and properpositioning, repair or replace faulty parts.

6. Inspect for damage to the arc chute sides and contamination inthe throat area.

a. The throat area may be cleaned with sandpaper, (do not useemery cloth or other metallic abrasives). Heavilycontaminated parts should be replaced.

b. Small cracks in the fins of the arc chutes do not interferewith the operation of the device and may be disregarded.

c. If the arc chute has suffered any other damage such asbreaking off of fins, the arc chute should be replaced.Small broken corners on the exhaust end of the chute sidesmay be disregarded.

7. Check the operating mechanism for friction by raising the tripbar and slowly rotating the manual operating handle in the closedirection. The linkage should follow the handle withoutsticking.

a. Restrain the UVTA and manually close the breaker.

b. Push the "push-to-trip" button to trip the breaker.

1) The toggle linkage should collapse and the movingcontact assembly move freely to the full open position.This should be followed immediately by completeresetting of the links in the toggle mechanism.

2) The links must always be free to move without frictionor binding.

c. Remove the UVTA restraint.

8. Check the control relay, as follows:

a. Examine the contacts for burning, wear and pitting; replaceif necessary.

DC0128 6XIV

DIABLO CANYON POWER PLANT UNIT NO(S) 1 AND 2NUMBER MP E-51. 7

REVISION 6DATE 4/11/85PAGE 7 OF 13



b. Disconnect the closing coil leads from the control circuitand restrain the UVTA reset lever.

c. Energize relay operating coil and slowly close the breakermanually. The relay release arm should operate the relaytrip assembly and open the relay contacts just before thebreaker latches. If the sequences are not correct the relayarm may be bent to suit.

d. Verify that the relay release arm does not rub on eitherside of the trip assembly lever aperture.

e. When the breaker is latched, deenergizing and thenenergizing the relay operating coil should not close thecontacts.

f. Trip the breaker, remove the UVTA restraint'and reconnectthe closing coil leads.

9.'nspect the auxiliary switch for loose bolts and excessivecontact wear; also verify that the contacts are touching beforethe end of travel.

10. Verify proper operation of the undervoltage trip attachment(UVTA) (Reactor Trip 8 Bypass Breakers Only) as follows:

a. If sticky or gummy substances are present on the linkage,clean with 190 proof ethyl alcohol and use it sparingly.

b. Lubricate the UVTA with Lubrication Kit No. 693C500G04, PGSE

Code b'50-2327.

2)

Thoroughly mix the contents in the glass container oflubricant by shaking vigorously for at least twominutes.

Place a cloth beneath the UVTA while applying lubricantto collect over-shoot and run-off lubricant.

3) Pour lubricant into plastic container and attach thedispensing tube assembly. Tighten the tube assembly onthe container. Pull gently on tube to verify that itis fully extended.

DC0128 7X IV




5)

While using the lubricant, shake the container aboutevery minute to keep the lubricant from settling out.

If the contents have been left standing for longer than5 minutes, mix the contents by shaking vigorously forat least two minutes.

6) Apply the lubricant liberally at the following pointstaking special care to reach all existing or potentialmetal-to-metal points of contact. Manually exercisethe UVTA during application of the lubricant.

Refer to Figure 2.

a) Latch to Latch Spring

b) Latch Loop to Latch Guide-pin

c) Latch to Latch Pin

d) Latch Pivot Points

e) Pin running through the trip Spring.

7) If lubricant is to be stored overnight or longer, thefollowing steps should be performed.

a) Remove dispensing tube assembly from container andpour lubricant into original container and sealwith cap.

b) Wipe excess lubricant from outside surface ofdispensing tube with a clean towel or cloth.

c) Add k to $ inch of solvent to dispensing containerand attach dispensing tube assembly to top ofcontainer, then shake.

d) Invert dispensing container to wash lubricant fromdispensing tube. 12 to 15 drops should cleantube. Remove dispensing tube assembly, discardexcess, solvent, and store the clean dispensingtube assembly for future use.

DC0128 8XIV




c. Reassemble breaker prior to proceeding..

d. Verify that the trip lever has approximately 1/32 to 3/32inch clearance to the trip bar when the breaker is half wayclosed.

e. Load the trip bar (per Fig. 3) with the 20 oz. weight.

f. Energize the undervoltage coil with 48 VDC and manuallyclose the breaker.

g. Reduce voltage to within ~ 5 volts of average voltagerecorded above.

h. Decrease voltage slowly (15 sec/volt) until the breakertrips. Record voltage.

Repeat the test twice and average the three readings.Record the average voltage.

j. Replace the UVTA in accordance with Maintenance ProcedureE-51.7A if any of the following criteria is met.

1) Dropout voltage is greater than 28.8 volts or less than14.4 volts.

2) Dropout voltage differs by more than 5 volts from theprevious dropout voltage.

3) The voltage trends downward over 2 successive testintervals by 2 or more volts.

k. Check the mounting bolts tight.

l. Remove 20 oz. weight and voltage supply.

11. Check the operation of the shunt trip attachment as follows:

a. With the breaker in the open position, manually push themoving core against the stationary core and rotate thebreaker handle to the closed position. The breaker shouldtrip free.

b. The trip lever should have from 1/32 to 1/8 inch clearanceto the trip bar.

DC0128 9XIV

DIABLOCANYON POWER PLANT UNIT NO(S) 1AND 2NUMBER MP E-51.7REVISION 6DATE 4/11/85PAGE 10 OF 13

TITLE:MAINTENANCE OF WESTINGHOUSE TYPE DB480 VOLT CIRCUIT BREAKERS

c. Load the trip bar (per Fig. 3) with the 20 oz. weight.

d. Restrain the UVTA and manually close the breaker.

e. Connect an adjustable (0-120 VDC) DC voltage source to theshunt trip coil.

f. Increase voltage to within ~ 5 volts of the average pickupvoltage recorded above.

g. Increase voltage slowly (15 sec/volt) until the breakertrips. Record voltage.

h. Repeat the test twice and average the three readings.Record average voltage.

i. Replace the shunt trip coil if any of the following criteriais met.

1) Pickup voltage is greater than 70 volts.

j. Check mounting bolts tight.

k. Remove 20 oz. weight and manual UVTA restraint if used.

12. Breaker Response Time - UVTA (Reactor Trip and Bypass Only)

a. Connect timer to the breaker.

b. Energize the undervoltage coil with 48 VDC and manuallyclose the breaker.

c. Trip breaker and start timer with control switch. Recordtime in milliseconds.

d. Repeat the test twice and average the three readings.Record average time.

e. Notify Maintenance Engineering if response time is greaterthan 167 milliseconds.

13. Breaker Response Time - Shunt Trip (Reactor Trip and Bypass Only)

a. Connect timer to the breaker.

DC0128 10XIV

DIABLOCANYON POWER PLANT UNIT NO(S) 1 AND 2

I', TITLE:MAINTENANCE OF IIESTINGHOUSE TYPE DB


NUMBER MP E-51.7REVISION 6DATE 4/11/85PAGE 11 OF 13

b. Restrain the undervoltage trip coil and manually close thebreaker.

c. Trip breaker and start timer with control switch. Recordtime in milliseconds.

d. Repeat the test twice and average the three readings.Record average time.

e. Notify Maintenance Engineering if the response time isgreater than 167 milliseconds.

f. Remove voltage sources, etc.

14. Using a spring force scale or a force gauge, pull or push up (perFig. 3) vertically on the trip bar. Record the force in ouncesat the instant of breaker trip. The trip force should be 31 oz.or less.

a. Remove the UTVA restraint.

15. Lubricate contact clusters with G.E. D50H47 grease.

16. Inspect the spring-loaded positioning lever for the following:

a. Lever should be undistorted and move freely.

b. Stop pin should be undistorted.

c. Trip arm should be undistorted.

d. The trip lever arm should have greater than 1/16" clearancefrom the trip bar.

17. Take the following measurements.

a. Contact resistance with a "Microhm" meter

1) If the resistance is 20% greater than the previousreading notify the Electrical Foreman.

b. Megger the main contacts with a 1000 volt Megger.

1) Two Megohms or greater is acceptable.

DC0128 11XIV

DIABLO CANYON POWER PLANT UN.T NO(S) 1 AND 2NUMBER MP E-51. 7

REVISION 6DATE 4/11/85PAGE 12 OF 13



c. Megger the control circuits with a 500 volt Megger.

1) Two Megohms or greater- is acceptable.

18. Manually operate the breaker to check for free operation.

19. Electrically operate the breaker to verify that all functions arenormal.

a. Close breaker

b. Trip breaker with shunt tripc. Repeat test twice

d. Close breaker, reactor trip and bypass breakers only.

e. Trip breaker with UVTA, reactor trip and bypass breakersonly.

f. Repeat test nine times, reactor trip and bypass breakersonly.

20. Test the overcurrent tripping devices (motor-generator breakers52-1 and 52-2 only), as follows. Document on Form 69-9546,

a. Lon Dela Pick-U is set at 120Ã of the coil rating ands ou pic up at 1080 to 1320 amps.

b. Lon Dela Calibration is set at 20 sec. With 600 percentamps of t e coil rating applied the unit should trip

in 15 to 25 seconds.

c. Instantaneous Pick-U is set at 8 times (8000 amps) the coilrating an s ou d trip the unit in less than 1 sec.

21. Verify that all tools, weights, etc. are removed from breaker.

a. For reactor trip and bypass breakers g.C. shall also verifythat all tools, weights, etc. are removed from the breaker.

22. Prior to replacing breaker visually check coil for cleanliness.

23. Replace breaker in cell. Verify that the correct breaker isreplaced in the cell. (Do not interchange)

l

DC0128 12X I V

DIABLOCANYON POWER PLANT UNIT NO(S) 1 AND 2



NUMBER MP E-51.7REVISION 6DATE 4/11/85PAGE 13 OF 13

'I

24. Report off clearance. Notify Shift Foreman that equipment isavailable for post-maintenance testing.

25. For reactor trip and bypass breakers a copy of the completed Form69-10647 shall be sent by the responsible foreman to MaintenanceEngineering for trending.

REFERENCES

1. Westinghouse Manual I.B. 33-850-3D DC 663197-40

2. Westinghouse Technical Bulletin No. NSD-TB-83-02, No.NSD-TB-83-02 Rev. 1 and No. NSD-TB-83-03

3. Procedure for Testing Mechanical Trip Force of Westinghouse DB-50Breakers Utilized for Reactor Trip Switchgear.

4. NRC IE Information Notice No. 83-18

5. NRC IE Bulletin No. 83-01

6. Maintenance for DB-50 Reactor Trip Switchgear, Rev. 0, 10/14/83

DOCUMENTATION

1. Completion of the following, as applicable, is required fordocumenting performance of this procedure.

a. Westinghouse DB-50 Circuit Breaker Overhaul, 69-10647

b. Low Voltage Circuit Breaker Test Form, 69-9546

2. Blanks on the form that do not requi re data must be initialed todocument performance. If the step is not required for thebreaker, indicate by placing a N/A in the appropriate block.

ATTACHMENTS

1. Cross-Sectional View of Type DB-50 Circuit Breakers

2. Undervoltage Trip Attachment lubrication Points

3. DB Bkr. Field Test - Trip Bar tripping Force

4. Typical timer connections, Fig. 4 and Fig. 5

5. Form 69-10647, "Westinghouse DB-50 Circuit Breaker Overhaul"

DC0128 13X I V

1504 4t1U I C500

MCVING ARC NG

guS~t.irj~t- ImMECHANISM-302

~rrv 4q~ S g

'V

~g~4p<:Id

rl iy gI, lsII~ /II ~ III(os

:I:;I I;'IJ i!I~ ~-,o

~ o ~ r O' ~ OI A Irorr IOOI,

ARC',."4G

314

uPFKR S-, -„3I 3

Qi Q4PL'Si TRIP I V3rv

f

I: 5(,y,I v QI 0

X

II ~ ~

rooooo i~oo o o+

oooo~o«~

I ~ I

fnI ~

r1 ~

I

l

~MAIN MCVINGCON ACT3I2

Tnlp Si ~EW5ll

Gl~~SG-.Cc:«~™;.

IVXII 'ARYMAINC NTACT5IC

MOVINGCCNi»'CTHlNGE509

A ~

LOWER Fii C

I'.r N~L='

Ig

o i+

CLOSING LCLQSING

SOLENOID

-'LOWER COILTERMINAL306

LOVERCURRENTRIPP!NG CEVICE509

UFo==, " ILI" .MINAL506

CLOSED TRIPPED OPW (RESET)

Fig. I - Cross-Sectional View ol Type DB-50 Circuit Breaie.

a. Latch to La.ch Sprinc

b. Latch Loop to Latch Guide-p'n

c. Latch to Latch Pin

Reset Lever

Latch SpringLatch Pin

CoilReset Lever SpnngAdjustment

Moving Core

Mica@a Acx.'

FmmeBreaxer

TnpBa

Coil

StaDonap/ CoreTrip Spnng

Undervoftage Trip Attachment

d. Latch Pivot Pointse. Pin Running Through the

Trip SpringFigure 2

PoNIT suHERE/o cE/5 P/ERST'<EO S1PAEu&4 ul'AR

0 75Wr nmx 7R)P 88'.

Poseur ewEm ~~Jg w~sudg-y 8gpuyhw14 uP HER,

uvre

69-10647 (20) 2/85PACIFIC GAS AND ELECTRIC COMPANY

DEPARTMENT OF NUCLEAR PLANT OPERATIONSDIABLO CANYON POWER PLANT UNIT NOS. 1 AND 2

TITLE'ESTINGHOUSE DB-50 CIRCUIT BREAKER MAINTENANCE - MP E-51.7

Page 1 of 5

EQUIPMENTSERIAL NO.OVERHAULED BY

BREAKER OPERATIONS

BREAKER NO.MIN AMPSDATE

FR M C UN ER

Dismantle breaker to the extent necessary to perform thefollowing steps as applicable. Blanks must contain Data,Initials or N/A.

l.a Measure the force required to trip the breaker

1.b Measure the Dropout voltage for the UVTA and verifybreaker trips

OZ ~

Test Weight

1.c Measure the Pickup voltage for the shunt tripand verify breaker trips

AVG

Found Lef

Condition

1.d Breaker Response Time Verification - UVTA

AVG

l.e Breaker Response Time Verification - Shunt Trip

AVG

3.a Verify that the following retaining rings are secure:

AVG

1. Moving'ontact Hinge Pins2. Stationary Arcing Contact Hinge3. CrossBar4. Operating Mechanism Hinge Pins5. Auxiliary Switch Linkage6. Pantograph7. Positioning and Interlock Level

(6)Pins (6)

(2)(8) 5L/3R(3)(6)(2)

DC0128 14V

69-10647 (20) 2/85

TITLE: WESTINGHOUSE DB-50 CIRCUIT BREAKER MAINTENANCE - NP E-! 1.7

Page 2 of 5

Dismantle breaker to the extent necessary to perform thefollowing steps as applicable. Blanks must contain Data,Initials or N/A.

3.b Check all Hinge pins and slides for wear

3.c. Check the pole bases for cleanliness and cracks

Found Left

Condition

Bg

3.d Check a visi e o ts and nuts for tightness

3.e Check insulating link

3.f Check wiring

4. Verify Gap "G" >0.050" and (0.093" (Refer to Fig. 1)

Cg

4.c Check main and arcing contacts for burning and pitting,clean or replace as required

Bg

Cg

5. Check main contact finger (clusters) to verify that theA'etainers are not cracked or bent and fingers are in

proper conditionBP

6. Check arc chutes for arc damage or cracks

7. Check closing solenoid and operating mechanism for evidenceof misalignment due to loose bolts

Check control relay for excessive contact wear and correctoperation

Check auxiliary switch for loose bolts and excessive contactwear

DC0128 15V

69-10647 (20) 2/85

TITLE: WESTINGHOUSE DB-50 CIRCUIT BREAKER MAINTENANCE - MP E-51.7

Page 3 of 5

ConditionBlanks must contain Data, Initials or N/A.

10. Check undervoltage trip attachment for defects in moving parts

10.b.6 Apply 53701GW lubricant to the following:

a. Latch to Latch Springb. Latch Loop to Latch Guide-Pinc. Latch to Latch Pind. Latch Pivot Pointse. Pin running through the Trip Spring

10.c Reassemble the breaker prior to proceding

10.d Verify the clearance from the UVTA trip lever to thetrip bar is greater than 1/32" and less than 3/32"

10.h and i Measure the dropout voltage for the UVTAand verify breaker trips

Foun Left

10.j Is UVTA acceptable? (YES/NO)

11. Check shunt trip attachment for defects in moving parts

ll.b Verify the clearance from the shunt trip lever to thetrip bar is greater than 1/32" and less than 1/8"

AVG

11.g and h Measure the pickup voltage for the shunt, coil and 1

verify breaker trips2

ll.i Is shunt trip acceptable'YES/NO)

12. Breaker Response Time - UVTA

AVG

AVG

DC0128 16V

69-10647 (20) 2/85


Blanks must contain Data, Initials or N/A.

13. Breaker Response Time - Shunt Trip

Page 4 of 5

ConditionFound Left

AVG

14. Measure the force required to trip the breaker"

15. Lubricate main and control contact fingers witha thin film of contact lubricant

16. Check the spring-loaded positioning lever

17. Take the following measurementsContact resistance on main contacts with a "Microhm" meter

A B

Megger rea er contactsA-B B-CA-Gnd B-Gn

Megger contro c>rcusts to ground

C-AC-Gnd

Megohms

18. Manually operate the breaker, verify free operation

19. Electrically operate breaker, verify free operation

Breaker Operations

TEST EQUIPMENT USED

SHUNT TRIPUVTA TRIP

(FROM COUNTER)

TYPE CO NO CAL. DATE

ELECTRICIAN QUALITY CNTRL

DC0128 17 V

69-10647 (20) 4/84


22. Verify cleanliness of cell

23. Verify that breaker has been replaced in the correct cubicle

Page 5 of 5

REMARKS

25. SEND COPY OF COMPLETED FORM TO PPE MAINTENANCE [ j

APPROVED BY DATE

DC0128 18V

0

Documents

of Westinghouse DB Volt Circuit Breakers · Identify weight on form. 2) Energize the undervoltage coil with 48 VDC and manually close the breaker. ... 6 2/pol e 6 2/pol e 8 5 Left/3