ML20246M219

Procedure MS-3.2.1.9-1B, Maint & Surveillance Ite Medium Voltage Switchgear Equipment

ML20246M219
Person / Time
Site:	Cook
Issue date:	03/21/1989
From:	ABB POWER DISTRIBUTION, INC.
To:
Shared Package
ML17325B169	List: ML20246M219
References
REF-PT21-89 MS-3.2.1.9-1B, NUDOCS 8903270072
Download: ML20246M219 (12)

Text

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m s 3.2.i.9.,B ASEA BROWN BOVERI Maintenance and Surveillance I-T-E Medium-Voltage Switchgear Equipment L

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HK Switchgear IB 3.2.1.7 1 5HK 250 and 350 IB 6.2.1.7-1 7.5HK 500 and 15HK 500/750 IB 6.2.2.7 1

!I 15HK 1000 IB 6.2.3.7-1 i,

S Enock O NS$315 PDR; 1

- MS 3.2.1.91 - ,

Page 2 1 4 RECOMMENDED MAINTENANCE & SURVN.ANCE ,

SHK,7.5HK & 15HK SWITCHGEAR EQUIPMENT '

EQUIPMENT MAINTENANCE PROGRAM This Bulletin augments the information If it becomes apparent after several and instructions provided in Instruction maintenance cycles that certain act-Bulletin 3.2.1.7-1. ivities we not ' needed as frequently as

=;;;;asted, or that increased frequency l Switchgear installations which require would be prudent, the program should be exceptional dependability due to serious adjusted to meet the specific needs of safety or economic consequences of op- the installation.

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. erating problems should be given com-prehensive maintenance and surveillance RECORDS attention. ~ This program' recommendat-ion 'has been developed specifically for Records are a key factor in a preventive use 'in . Nuclear Power Generating' Sta- maintenance program and can provide

- tions but it is applicable to any install- vital data for evaluating equiment cond-ation where exceptional reliability is de- ition, when necessary, if the recording q

<. sired and a preventive maintenance pro- - .

system is-consistent, thorough and avail-J gram is to be implemented. able when needed. As a minimum the records should contain the data and, for Some maintenance activities are consid- circuit breakers, the number of ered essential, therefore ACTIVITIES operations at last maintenance in add-WHICH ARE MOST - IMPORTANT TO ition to results of testing. If observa-ASSURE AVOIDANCE OF PREDICT- tions of equipment condition are record-ABLE PROBLEMS ARE UNDERLINED. ed, a realistic basis for adjusting main-

. tenance frequency will be available.

FREQUENCY OF MAINTENANCE SPARE PARTS Suggested time frames in the program are not absolute, they represent the best A major factor in overall availability is i

generalized advice of the manufacturer down-time-per-failure or mean-time-to-

'or equipment installed in - a clean, repair and although switchgear and uncontaminated environment such as associated components enjoy favorable may be found in a power generating reliability expectations, random failure station. If equipment is in an area whe e of a component can cause down-time or corrosive or conductive contaminants are reduced capability if inadequate atten-present, or if large amounts of airborne tion is given to the spare parts contaminants will be experienced, the inventory. A spare parts recommenda-shortest interval of the range shown in tion for the switchgear equipment can be the equipment maintenance program provided to assist in selection of appro-should be used. Further, in highly priate parts. Storage of spares should be contaminated areas as described, circuit in a clean, dry area. Part access and breaker servicing should be accomplished identification should permit prompt l at a maximum of two year intervals. availability, when needed. ,

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MS 3.2.1.9-1 Pmje 3

1. GENERAL 2. RECEIPT AND STORAGE CAU'ITON: BE SURE THAT ALL ELEC- Environmental conditions during TRICAL SUPPLIES ARE OFF BEFORE transit and storage . can have a PERFORMING ANY MAINTENANCE substantial effect on equipment INSIDE EQUIPMENT. reliability. Extended periods of r storage with ' original shipping

a. The following lubricants are covers in plact must be avoided.

recommended:

a. Upon receipt, equipment LUBRICANTS should be put into a ventilated storage area protected from Mechanisms ANDEROL 757 the weather. Temperature (anti- Tenneco Chem. should be tnaintained between friction) Inc. 40"F and 120 F, humidity

- should be maintained at 50 %

Electrical NO-O X-ID relative

• or below. Shipping Contact "A Special" covers and/or boxes should be Compound Sanchem Chem. Co. removed.

e Use of other lubricants risks *If relative humidity above incompatibility with original 50% is anticipated, localized materials or unproven per- heat sources should be provid-formance. ed to maintain equipment

b. In tightening i lted conductor temperature above the dew connections, use of a torque point. One means of accom-wrench is recommended. The plishing this is to energize following torque levels will

• internal equipment space assure good connae' dons: heaters and store circuit breakers within the equipment DRY THREAD 'IORQUE enclosures. Note that equip-ment must be on a flat level BOLT DIA. TORQUE surface to avoid floor distortion.

3/8" 15-25 f t. lb.

1/2" 30-45 ft. Ib. b. Under all conditions of trans-5/8" 50-75 f t. Ib. port and storage, equipment 3/4" 65-80 ft. Ib. should be protected from direct impingement of water,

c. A clean and dry environment flooding and heavy contamin-should be a continuing goal of ation, such as construction '

the maintenance program for dust and dirt.

all electrical equipment.

3. AT INSTALLATION (Repetition of

d. Operating and maintenance some factory activity is suggested personnel should be alert for due to uncertainties of shipping, i

unusual sounds (sizzling or handling, etc.)

crackling) and smells (ozone l or burning) when in the vicin- CAUTION: TURN OFF ALL POWT'R ity of electrical equipment. BEFORE WORKING INSIDE.

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[ MS 3.2.1[91 ,

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l' . a. - Equipment mounting should be j. Millivolt ' drop and timing -

on level rails embedded flush measurements on.each circuit -

, with the < finished floor per breaker provide; useful preop .

installation dwas. eration. checks and ; valuable -

comparative i data 1for future -

b. Removal 'of all shipping sup-- 'use.

ports and installation of all bus conductors (main and 4. SIX TO EIGHTEEN MONTH INTER-ground) across shipping splits VALS

should be verified.

CAUTION: ' TURN OFF ALL - POWER

c. Check all bolted bus connect- BEFORE WORKING INSIDE. ' ,

ions for proper torque.

a. Identify and service' circuit

d. Check circuit breaker connec- breakers which are due. See

. tion wipe by applying NO-OX- CIRCUIT BREAKER SERVIC-

.ID compound to- stationary ING section, Page 6 of this

" connection stubs and racking Bulletin.

breaker into connected posi-

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tion, then out. Contact lines b. Exercise all circuit breakers in compound verify contact. which are not due for service.

e. Exercise each circuit breaker c.' Inspect primary interface (close and trip twice.) connections with other equipment for signs of exces-

f. ' Inspect primary conductor sive heat (Cable and bus con-insulation . system, remove nections, usually in the rear contamination accumulated in of the equipment.) Discolor-storage and installation. ation - or embrittlement of adjacent insulating materials

g. Check primary cable connee- and conductor corrosion or tions for tight hardware and discoloration may indicate a proper stress relief. Check hot joint. ~ Ste HOT JOINT all primary connections to MAINTENANCE, Page 5.

other electrical equipment.

d. Inspect primary cables for chafing at conduits or sup-

h. Check control wire connee- p ris and loose or missing tions - See 6b.

stress relief grounds.

i. Check trip / racking interlock to verify no racking with

, , e. Exercise the racking mechan-ism.

breaker closed and no closing unless breaker is latched in position.

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% . MS 3.2.1.91

. Page 5 i l

53 ONE TO' THREE YEAR . INTER- ' M AINTEN ANCE,3belown Re .

JVALS!(Nuclear - Alternate refuel-. ~ appip i NO-OX-ID compound ing shutdowns.) prior to reconnecting circuit breaker.

CAUTION: TURN ' OFF ALL" POWER .

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BEFORE WORK]NG INSIDE. NOTE

Protective ; relays) should typ .

lically' be checked for accuracy of c'ali-a._ ._ Clean contamination ' from ' all bration at two to five year _ intervals, see primary insulation with- ' manuf acturers instructions for detail. .

vacuum, distilled water or a .

solvent approved by NIOSH or 6. TEN _ YEAR MAXIMUM INTERVAL local authority, as neces-sary. Inspect for discolora- CAU'ITON: TURN OFF1- ALL POWER tion or other evidence of BEFORE WORKING INSIDE.

excessive heat. If found, proceed per' HOT - - JOINT a. All primary ' conductor con-

. M AINTEN ANCE, below. nection bolts should -be torqued to recommended '

' b. Inspect control wiring bundles values. (An alternative to p~ fe ~ discoloration due to heat, retorquing may be_use~~ of b chafing , or other damage to  : infrared heat sensor (thermo-iraulation.'

graphic); techniques.' These procedures 'are specialized,

c. Clean ' stationary breaker con- however, and! require plans to inection stubs in the' enclosure overcome ' loading and safety _

with a solvent approved by difficulties.) See below.

NIOSH or local authority.

Inspect for evidence of con-

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b. Tighten all' secondary control

. tact galling,' excessive heat, wire connections while check-arcing or. corrosion. If found, ing for loose lug crimps and

. proceed per; HOT . JOINT broken wire strands.

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3 HOT JOINT MAINTENANCE - For primary joints which show evidence of er.cessive heat (1) Open joint and inspect connection surfaces. (2) If surfaces appear reasonably smooth, with only minor pitting or corrosion, clean and dress contact surfaces minimizing removal of plating. (3) If surfaces are heavily pitted or corroded, or if there has been any melting of conductor material,~ the affected parts must be replaced. (4) Replace contact finger springs if breaker disconnects have been exposed to excessive heat. (5)

Contact surfaces should be protected with NO-OX-ID before re-assembly. (6) Use recommended torque values in tightening bolted connections. (7) Before and after millivolt drop testing can provide some confidence that the problem has been corrected.

JOINT COVERS - During surveillance it may be necessary to remove joint covers. It is possible that the cover may crack when it is flexed for removal or replacement due to embrittlement from loss of plasticizer. An isolated incidence of such cracking indicates that the joint has been operating at higher temperatures than normal. A cracked cover should not be reused. An embrittled cover which has not cracked will provide insulating capability at least as long as it took to embrittle. Generalized embrittlement of joint covers is not expected for twenty years or more.

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MS 3.2.1.9 .

Page 6 CIRCUIT BREAKER SERVICING 5HK-250, - 7.5HK-500, 15HK- I 500/750 - 750 operations.  ;

Circuit. breakers require inspection and  !

servicing periodically to assure operabil- 5 HK-3 50,- 15HK 1000. -

L400-

ity. Servicing should be accomplished . operations.

based on number of operations since last serviced, with an elapsed time ' limit. FAULT INTERRUPTION The ' appropriate . frequency of servicing depends on the duty of the circuit break- Service a breaker which has inter-er. As experience warrants, the recom- rupted short circuit current as soon mended frequency of servicing 'shown as possible.

below should be adjusted on ' specific breakers to account for more/less severe This service program qualifies a circuit duty than initially expected, based on the breaker for the total number of opera-breaker condition when serviced. tions shown below before replacement or  ;

factory refurbishment is required. The '

Recommended service frequency is limit is suggested to provide margin. i shown - for three general categories of l duty: 15HK-250, . 7.5HK-500, . 15HK- l 500/750, Total Operations - 10,000, l LOAD CURRENT SWITCHING, UP Suggested Limit 9,000.

TO RATED CONTINUOUS CUR-RENT ENVIRONMENT NORMAL, SHK-350,' 15HK-1000, Total MINIMAL CONTAMINATION. Operations - 5,000, Suggested Limit

- 4,500.

Service breaker every five (5) years or . upon accumulating the number The following should be accomplished at of operations shown below since each service interval:

last serviced, whichever comes first. CLEAN, INSPECT & LUBRICATE PRIMARY DISCONNECTS.

5HK-250, -7.5HK-500, 15HK-500/750 - 2000 operations. CONTACT & INSULATION CLEANING.

l 5HK-350, 15HK-1000 ' - 1000 PUFFER CHECK.

operations.

ARC CHUTE INSPECTION MOTOR START, CAPACITOR &

REACTOR SWITCHING OR ANY OPERATION CHECK DUTY IN A CONTAMIN ATED EN-VIRONMENT. CONTACT PRESSURE CHECK **

Service, breaker every two years or MILLIVOLT DROP TEST upon accumulating the number of operations shown below since last Instructions follow which clarify the serviced, whichever comes first, above.

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. . MS 3.2.1.91 Page 7 In addition, the hardware (bolts, nuts, LUBRICATION screws and pin retainers) should be checked with a thorough inspection to be The HK circuit breakers are lubricated sure that they are in place and secure. during factory assembly as follows:

There are other adjustments which may L be required due to the operating or test All mating surfaces of moving cur-abnormalities below: rent-carrying joints have been lubricated with NO-OX-ID Special TIMING TEST

• Grade " A" grease.

Should be run before and after the All other mechanism parts, bear-bridge pivot pressure adjustment ings, pins, etc. have been lubricated (below). Recommended as a perti- with ANDEROL 757.

nent periodic test to evaluate The circuit breaker mechanism does not I rea er condition.

ordinarily require lubrication in the usual  !

m deate serdce endronment expect-CONTACT PRESSURE ADJUST- ed. However, H operaung dMeuMes MENT ** are experienced, if grease becomes con-l taminated or if parts are replaced, relub-(*- Required if conta'et pressure check rication with ANDEROL grease may be l indicates a problem. required. Contact the nearest Brown Boveri Electric district office for field BRIDGE PIVOT PRESSURE assistance or factory refurbishing AD JU STMENT** arrangements.

Required when the millivolt drop Primary disconnect fingers should be test is above limits (pressure too cleaned, with a solvent approved by f low - resistance too high.) . NIOSH or local authority, inspected for

! corrosion or evidence of arcing and RACKING MECHANISM ADJUST- relubricated with NO-OX-ID grease at MENT ** each servicing.

I 4 Required if interlock fails to block NOTES:

closing while breaker is being rack-ed in or out or racking latch is not Do not use NO-OX-ID grease on arcing blocked with breaker closed. contact parting surfaces.

LATCH CHECK SWITCH Do not use light oil to lubricate AD JU STMENT** mechanism parts.

Required if circuit breaker fails to The spring charging motor is sealed, '

latch closed on reclosing. lubrication is not recommended.

• Specific guidance on the timing test is included in the following instructions:

SHK-250, 350 - IB 6.2.1.7-1, 7.5HK-500,15HK-500/750 - IB 6.2.2.7-1 and 15HK-1000 - IB 6.2.3.7-1.

• • Consult the circuit breaker Instruction Bulletin for guidance in Inaking the contact pressure check and adjustments.

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. MS 3.2,1.9-1 '

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1 CONTACT- AND- INSULATION CAUTION: . FOR SAFETY, KEEP CLEAR CLEANING - OF ALL MOVING PARTS..

Any dirt,-; soot or grease should be- ARC CHUTE INSPECTION -

removed fromi the circuit' breaker con- , , ,

. tacts - and surfacefof entire : current . The are chutes should be inspected inter-carrying stru'eture, 'as well as all insula- nally to insure that no breakage occured tion surfaces, with a cloth saturated with to the liner plates. Further, there may an. approved solvent. Cleaning of the ' be- a crust formed on the liner plates if insulation is;important because, contam- the load current interruptions were close -

inatian can - accumulate and, with to the continuous . current. rating of the moisture, can place the circuit breaker breaker or moderate faults were inter-in jeopardy, dielectrically. rupted. . This crust should be removed with are chutes off the breakehoy care-A ' degree of burning and pitting on the fully - using '~ a carborundum ' stone or circuit breaker arcing contacts is to be scraper. The are chute should be blown expected from~ normal operation; on out with' dry air to' remove the resultant i highly inductivei or. capacitive circuits dust and particles.

and after major interruptions, some pit-(ting may occur on the main' contacts.

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4 Arc plate and liner plate breakage should

- When necessary to dress the contacts, be carefully looked L for, along ' with cover the puffer nozzle with a cloth, excessive erosion of the are plates. The then follow- the contour .of the contacts are plates are made of ceramic material with a fine file. Do not attempt to elim- and perform the function of extracting -

inste pitting entirely. After this maint- heat from the are as it'is being forced enance, the contact pressure and milli- into and elongated by them. The leading .

volt drop should be checked; adjustment edges become coated with - glass that 1 -

. should be made, if indicated. comes to the surface from the extreme heat. A- direct measure of use is the

' NOTE: Replacement of, contact need

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amount ~o f ceramic ' surface with glass only be considered when after repeated beads evident.

i dressing of contacts, less than 50% of the original contact material thickness is When the entire leading edge and left, the .. tips of the stationary arcing portions of the flat are plates are noted contacts have been eroded away, or any to be heavily encrusted with glass beads, contact has been broken, cracked or the are chute should be replaced. It burned through. should be noted that this condition will vary between are chutes on the same PUFFER CHECK breaker because of a single-phase fault and asymmetrical current incidences. If The performance of the puffers can be there are any questions, Brown Boveri readily checked during servicing. Each Electric, Inc. Switchgear Systems  ;

puffer should provide a moderate blast of Division should be consulted for air at the breaker contacts, on opening recommendations.

of the circuit breaker. This can be '

detected by holding a sheet of paper over OPERATION CHECK the top of the contacts and opening the circuit breaker. All three poles must During servicing it is desireable to verify have puffing action or else the circuit breaker operability. It is recommended breaker must not be placed in service. that this be done at the minimu:n i

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. M.S 3.2.1.91 . . ,

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, TIMING TEST T. -

lThe circuit breakerf closing and: opening x .s.. ,

times should be' within the following time

, After. a change in ' bridge pivot ; adjust . ranges for normal operation.

. ment,iand , periodically,

if. a functional ~

check. is desired,.the closing and opening - ' NOTES: Below: O C, .~the' closingTtimes

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- . times should be : checked' by use =of- a'

. will increase, opening times will be with-

[L . time-travel .. analyzer *, . oscillograph- or in the limits.

h . cycle ' counter to monitor 'the time from energizing the control to arcing contact  : If timing is .. outside the.. limits,"; the

. touch or part.. f. factory should be.. contacted for'recom-mendations.

CIDSING TIME - OPENING ~ TIME-CIRCUIT BREAKER RANGE - MS** RANGE - MS**.-

5HK250, 5HK350 i '

1200 Amp ~ 50-90 23-35 11 5HK250- '

2000 Amp 60-95 23-35 4 "5HK350 2000_ Amp- 50-90 23-35 3000 Amp 65-95 23-35 7.-5HK500, 15HK500, 15HK750-1200 Amp 105-140 '25-42 2000' Amp 105-140 ~25-42' 2500 Amp 105-140 25-42 15HK1000 1200 Amp 85-125 25-42 2000 Amp 85-125 25-42 3000 Amp 85-125 25-42 With 125VDC Control, timing may vary slightly at other control' voltages.

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• Analy::er mounting support and instructions available on special order.

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, MS 3.2.1,91

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expected - control'. voltage level. If the millivolt ' drop does not exceed-

. (Typically 80% of nominal).- m 150% of the values, shown'in the table on breakers with light loading, no contact

' MILLIVOLT DROP TEST maintenance ' is ; necessary.

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If 7 the millivolt drop does exceed 150% of the During iservicing, the ? resistance ' of the values, the main and arcing contacts circuit breaker current carrying parts should' be ' dressed ~~ with a fine . file, can be checked with a millivolt drop Tcleaned and adjusted for proper contact' test. This test should be ; performed-pressure ; and - then rechecked. -If the

- regardless lof circuit L breaker duty or ' values are still in excessof the -150% -

number of operations. - value, the bridge pivot pressure should be readjusted.

4 The following table lists millivolt drop and resistance values ' for the circuit If ' breaker loading is 75% or more of breakers, from . terminal . to terminal,~ rated current,it is recommended that the exch*.sive of the primary disconnects.' listed values be used as limits.

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E MAX MAXIht.1M MV DROP I MICRO-OHMS CURRENT RATING 5HK250, 5HK350 1200 Amp 9 45

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-' ~2000 Amp 7 35

.- '5HK350 20 j 3000 Amp 4 f; 7.5HK500, 15HK500

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15HK750 1200 9 45 2000 7 35 2500 7 35

.3000 6 30 15HK1000

~55- I 1200 11 I

2000 9 45 30 I i 3000 6 o

i (1) Mi11ivolt drop with 200 Amperes flowing.  :

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. . MS 3 2.1.91 Page 11

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ABB ASLA DROWN BOVE Fil

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ABB Power Distribution Inc.

4379 County Line Road Chalfont,PA 18914 Supersedes issue A

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Printed in U.S.A.1C CMC 785 l l

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