Type-3AFS Instructions Installation VacuumCircuitBreakers

SIEMENS

Type-3AFSVacuum Circuit Breakers

InstructionsInstallationOperationMaintenanceSG-3398

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Introduction 00

THIS EQUIPMENT CONTAINS HAZARDOUS VOLTAGES ANDMECHANICAL PARTS WHICH MOVE AT HIGH SPEED ANDMAY BE CONTROLLED REMOTELY. SEVERE PERSONALINJURY OR PROPERTY DAMAGE CAN RESULT IF SAFETYINSTRUCTIONS ARE NOT FOLLOWED. ONLY QUALIFIED PER-SONNEL SHOULD WORK ON OR AROUND THIS EQUIPMENTAFTER BECOMING THOROUGHLY FAMILIAR WITH ALLWARNINGS, SAFETY NOTICES, AND MAINTENANCE PRO-CEDURES CONTAINED HEREIN. THE SUCCESSFUL ANDSAFE OPERATION OF THIS EQUIPMENT IS DEPENDENTUPON PROPER HANDLING, INSTALLATION, OPERATION ANDMAINTENANCE.

»EPower circuit breakers are applied at highvoltages and have mechanical parts whichmove at high speeds and will cause death,personal injury and property damage.

To avoid injuries due to electrical shock,burns, and entanglement in moving parts, thisequipment must be installed, operated, andmaintained only by qualified personsthoroughly familiar with the equipment, in-struction manual and drawings.Qualified Person

Field Service OperationFor the purpose of this manual and on product labels, a qualifiedperson is one who is familiar with the installation, constructionand operation of the equipment, and the hazards involved. Inaddition, he has the following qualifications:

(a) Is trained and authorized to enegize, de-energize, clear,ground and tag circuits and equipment in accordance withestablished safety practices.

(b) Is trained is the proper care,and use of protective equip-ment such as rubber gloves; hard hat, safety glasses orface shields, flash clothing, etc., in accordance withestablished safety practices.

Siemens can provide competent, well-trained Field ServiceRepresentatives to provide technical guidance and advisoryassistance for the installation, overhaul, repair and maintenanceof Siemens equipment, processes and systems. Contact regionalservice centers, sales offices or factory for details.

Signal WordsDistinctive signal words (DANGER, WARNING, CAUTION) areused in this instruction book to indicate degrees of hazard thatmay be encountered by the user. These signal words are definedbelow.

DANGER Indicates death, severe personal injury orsubstantial property damage will result if pro-per precautions are not taken.

WARNING Indicates death, severe personal injury orsubstantial property damage can result if pro-per precautions are not taken.

CAUTION Indicates minor personal injury or propertydamage can result if proper precautions arenot taken.



Contents 02

Table of ContentsIntroduction

IntroductionTable of ContentsTable of IllustrationsGeneral

IntroductionReceiving"As Found" TestsStorageInstallation Checkout

Technical DataRating Plate ContentRating SummaryBreaker TypeService ConditionsGeneral Performance D a t a . . . .

Interrupter/Operator - DescriptionDescription—GeneralDescription and Operation

ConstructionBreaker PoleCurrent-Path AssemblyVacuum InterrupterThe Arc-Quenching Principle .Switching Operation

Operating MechanismConstructionIndirect ReleasesMotor Operating Mechanism.Auxiliary Switch

Mode of OperationChargingClosing

Interrupter/Operator (con’t)Trip Free OperationOpeningRapid Auto-Reclosing

Manual OperationManually Charging The Closing SpringManual ClosingManual Opening

Elementary DiagramIndirect Releases

Shunt ReleaseUndervoltage ReleaseConstruction and Mode of Operation . .

Interrupter/Operator - MaintenanceGeneralInspection ChecklistHand Tools Recommended

GeneralMetricEnglish

Minimum Maintenance ScheduleLubrication of the Operating MechanismHydraulic Shock AbsorberVacuum Interrupters

Life ExpectancyContact ErosionInterrupter Vacuum Check-Mechanical .High Potential Testing and Electrical

Interrupter Vacuum CheckVacuum Tube ReplacementSolenoid ReplacementOperational Check

Warranty

1300130213031414318318418419519196 207

721721821219 219 219 229 229 249

9 2410 2412 251212 26. 12 2712 3012 3012

3113

NOTEThe instructions contained within this manual are necessary for the safe installation, maintenance and operation of this equip-ment. If this manual is misplaced or lost, replacement manuals are available through the local Siemens sales office.

These instructions do not purport to cover all details or.variations in equipment, nor to provide for every possible contingency,to be met in connection with installation, operation or maintenance. Should further information be desired or should particularproblems arise which are not covered sufficiently for the purchaser's purposes, the matter should be referred to the localSiemens office.THE CONTENTS OF THIS INSTRUCTION MANUAL SHALL NOT BECOME PART OF OR MODIFY ANY PRIOR OR EXISITNGAGREEMENT, COMMITMENT OR RELATIONSHIP. THE SALES CONTRACT CONTAINS THE ENTIRE OBLIGATION OF SIEMENS.THE WARRANTY CONTAINED IN THE CONTRACT BETWEEN THE PARTIES IS THE SOLE WARRANTY OF SIEMENS. ANYSTATEMENTS CONTAINED HEREIN DO NOT CREATE NEW WARRANTIES OR MODIFY THE EXISTING WARRANTY.If drawings or other supplementary instructions for specific applications are forwarded with the manual or separately, theytake precedence over any conflicting or incomplete information in this manual.



Contents 03

Table of Illustrations1Figure

FigureFigure 2.Figure 3.Figure 4.Figure 5.Figure 6.

Figure 7.Figure 8.Figure 9.Figure 10.Figure 11.Figure 12.Figure 13.Figure 14. Typical Elementary DiagramFigure 15. Construction of Shunt ReleaseFigure 16a. Latch Detail Shunt ReleaseFigure 16b. Latch Detail Undervoltage ReleaseFigure 16c. Undervoltage Blocking FeatureFigure 17. Operator Lubrication PointsFigure 18. Typical Primary Interrupter Contact Life CurvesFigure 19. Contact Erosion CheckFigure 20a. Lower Pole Support with Insulated CouplerFigure 20b. Primary Contact Closed - Free PositionFigure 20c. Primary Contact Forced Open by Manual PressureFigure 21. Vacuum Tube Replacement IllustrationFigure 22. Illustration Showing Required Technique for Fastening Terminal Clamp Hardware

1a. Type 3AFS Vacuum Circuit Breaker Front View1b. Type 3AFS Vacuum Circuit Breaker Rear View

Rating PlateTypical Innterrupter /Operator AssemblySection Through a Vaccum Breaker PoleSection Through a Typical Vacuum InterrupterSection Through the Typical Vacuum BreakerOperating Mechanism Closed Position - Closing Springs DischargedDetails of Closing Spring Charging Components - Closing Springs DischargedOperating Mechanism Open Position - Closing Springs DischargedBreaker Shaft in Open Position - Closing Springs DischargedOperating Mechanism Section Diagrams: a, b, c. dOperator Sequential Operation DiagramFront View of Mechanism Enclosure Arranged for Manual Operation

26

1011111112131414

15-16171819202020202324252526262829

7Table 1.Table 2.Table 3.Table 4.Table 5.Table 6.Table 7.

Rating Summary & WeightsAltitude Correction FactorsOperating TimesClosing and Tripping Solenoid CharacteristicsSpring Charging Motor CharacteristicsAuxiliary Switch RatingsMaintenance Intervals

78888

22

Copyright 1988 - Siemens Energy & Automation



General Page 1

Figure 1a. Type 3AFS Vacuum Circuit Breaker—Front View.



General Page 2

Figure 1b. Type 3AFS Vacuum Circuit Breaker—Rear View.



General Page 3

Introduction ReceivingThe 3AFS series of vacuum circuit breakers are precision builtdevices designed to function efficiently under normal operatingconditions. They are designed and manufactured to operatewithin the ANSI C37 standards for “Indoor” oiless circuit break-ers. Performance requirements of these standards are met orexceeded by these designs.

Type 3AFS vacuum circuit breakers are shipped from the fac-tory completely assembled, inspected and tested. Immediatelyupon receipt of the circuit breakers, check each item with theshipping manifest andmake an examination for evidence of anydamage that may have occurred during shipment.

If any shortage, damage or indication of rough handling isfound, immediately call it to the attention of the local freightagent handling the shipment. Proper notation should be madeby him on the freight bill. This prevents any controversy whenclaim is made and facilitates adjustment. Also, immediately filea damage claim with the transportation company and notifythe nearest Siemens representative.

Specific Standards which apply include:

IEEE Standard Rating StructurePreferred Rating and Related RequiredCapabilitiesIEEE Standard Test ProceduresIEEE Standard Application Guide

C37.04C37.06

C37.09C37.010

The successful performance and application of these vacuumcircuit breakers depends as much on proper installation andmaintenance as it does on good design and careful manufacture.

NOTEDamage claims must be processed within the timeperiod specified by the carrier. Siemens cannot beheld responsible for shipping damage, either exter-nal or internal, if the inspection is not made and claimforwarded within the set time limit.

The instructions included in this book are necessary for safe in-stallation, maintenance and operation and are provided to aidyou in obtaining longer and economical service from yourSiemens Circuit breakers. For proper installation and operation—resulting in better service and lower maintenance costs—this information should be distributed to your operators andengineers.

Check and examine upon receipt and report any problems asindicated above. Carefully remove the packaging using thecorrect tools. The circuit breakers may be carefully lifted usingthe lift holes on the upper rear side of the operator housing. Seetable 1 for weights. Care should be taken not to damage theinsulators or circuit breaker during lifting or moving operations.

By carefully following these instructions, difficulties should beavoided. However, they are not intended to cover all details orvariations that may be encountered in connection with the in-stallation, operation and maintenance of this equipment.

Should additional information be desired, including replacementinstruction books, contact your Siemens representative.



General Page 4

“As Found” TestsWhen the circuit breakers are received perform and record "AsFound’ insulation tests using megger or Doble tests to give aninitial value for future comparative indication of insulation change.Contact resistant tests can also be made using a ductor. Thisis recommended for all new circuit breakers especially if theyare to be stored for extended periods as they may absorbmoisture and contaminants. This should also be done afterstorage and prior to placing breakers into service. Changes invalues between subsequent tests should be evaluated and cor-rective action taken where needed.

With the breaker open, check each phase across the open con-tacts by connecting from the upper (27) to the lower (29) primarydisconnect. With the circuit breaker closed, check phase-to-phase and each phase-to-ground.b. A 60HZ dielectric test on secondary and control circuits

should be made at 1125 volts (1500 x 75%) for one minute.

NOTECertain control devices such as, charging motors,pushbuttons, bell alarms, etc., may have only a 900volt rating. 75% of 900V would allow a field Hi-POTof only 675 volts AC.

Since wide variations can occur in insulation values and con-tact resistance because of atmospheric conditions, comtamina-tion and type of test equipment, discrete values cannot be given.However, making and recording these test on new equipment,and again at regular intervals, will give a comparative indica-tion of insulation and/or contact resistance change. Maintain-ing a permanent record of these values for each circuit breakershould be part of the Maintenance Program.

c . If dersired, contact resistance tests can be made using aductor.

d . Make a permanent record of all test performed.

StorageNOTE - If storage is necessary, “As Found” tests are recommended

prior to and after storage for comparison. For storage, thecircuit breakers should be kept indoors in a cleandry locationwhere they will not be exposed to such items as dirt, construc-tion dust, corrosive atmospheric mechanical abuse or rapidtemperature variation. If stored in their cubicles, space heatersor similar heat source should be used to prevent condensation.

Before testing, review the procedures and safetyprecautions indicated in the section ‘High PotentialTesting and Electrical Interrupter Vacuum Check’,page 29.

a. Insulation resistance test should be made to verify the in-sulation integrity. These can include megger or Doble tests.If possible, a high-potential test should be made for oneminute at:

RATEDVOLTS(MAX.)4.76 kV8.25 kV

15.10 kV

Outdoor storage of circuit breakers is not recommended. Ifbreakers must be stored outdoors, they must be completelycovered and protected from the elements. A heat source mustbe provided to prevent condensation and subsequent corro-

. sion. Often 500 watts heat per breaker is used. Covering shouldallow for ventilation.

TEST VOLTAGEA.C. D.C.

14,00027,00027,000

20,00038,00038,000 It is recommended that periodic inspections of the breakers be

made during storage and if necessary, procedures adjusted tokeep the breakers in proper condition.



General Page 5

Installation CheckoutThe following agenda provides a convenient check list of activ-

ities to be performed while preparing the circuit breaker for use.10. If of drawout design, the breaker shouldbe inserted into cell

to the Test/Disconnect position.

11. Ensure that secondary disconnects are fully engaged.

A DANGERh 12. Re-energize control power. Stored energy springs shouldautomatically charge. Close and trip the breaker electri-cally. Observe that the breaker operates properly and thestored energy motor recharges after the close operation.

Hazardous voltages and high speedmechanical parts will cause death or severepersonal injury and property damage.Read instruction manual, observe safety in-structions and use qualified personnel.

13. Move breaker to fully connectedposition ona de-energizedbus. Close and trip breaker from main control position.

14. If a lock-out key interlock position has been provided in thecubicle, place the interlock in the breaker “Trip-Free” posi-tion, key removed, and perform a close operation. Checkthat the breaker has gone trip free. Open the interlock “keyheld’’ position and repeat the closing trial. The breaker nowshould successfully close.

1. Carefully remove the packaging using proper tools. Vac-uum breakers are normally supplied with their primary con-tacts open and stored energy springs discharged. Presstrip (54), close (53), and again trip push buttons to confirmthis is true.

Refer to “Receiving” section for lifting alternatives.15. The breaker should now be ready for service.

2. Carefully note and check rating plate (51) per Figure 2 toensure maximum voltage, continuous current, interruptionrating, and control voltages are compatible with the systeminto which the breaker is to be applied. A DANGER

H Hazardous Voltages Associated with the ap-plication of this breaker will cause death, per-sonal injury, and property damage.

Before proceeding with the initial circuitbreaker insertion and racking to the bus, becertain the bus is de-energized.

3. Perform a careful visual inspection noting any damagewhich may have occurred in shipment. Clean all dust, dirtand foreign materials accumulated in shipment.

4. Using procedures described in themaintenance section ofthis manual, carry out a vacuum check.

5. Complete a manual spring charge, close and trip operation.

A WARNING6. Reinstall any barriers removed during inspection.

7. Connect control power to breaker. Upon energizing controlpower, closing springs should automatically charge. Thenclose and trip the circuit breaker electrically. H A fully connected breaker controls high

voltage and currents. Improper use cancause death, personal injury or propertydamage.

Perform initial racking to connect position onde-energize bus. If an energized bus isunavoidable obtain appropiate clearancesbefore beginning the next two steps.

8. Perform and record results of the “As Found” tests. Com-pare with pre-storage “As Found” test values if stored.

9. De-energize control power. Press trip (red), then close(black) and then trip pushbuttons to confirm breaker isopen and springs discharged.



Technical Data Page 6

Rating Plate ContentType Designates circuit breaker model number

and broadly identifies application in termsof maximum voltage and interruptioncapability.Rated continuous current is the disignatedlimit of current in RMS amperes at ratedfrequency which the breaker may be ex-pected to carry without exceedingtemperature limitations.

The highest RMS voltage above nominalsystem voltage for which the circuitbreaker is designed, and is the upper limitfor operation.The ratio of rated maximum voltage to thelower limit of the range of operatingvoltage in which the required symmetricaland asymmetrical interrupting capabilitiesvary in inverse proportion to operatingvoltage.

The rated full wave impulse withstandvoltage. The crest value of a standard 1.2x 50 impulse voltage wave which a newcircuit breaker must be capable of with-standing without flashover or punctureduring design tests.The symmetrical component of short-circuit current in RMS amperes which thebreaker may be expected to interrupt.The maximum making current into whichthe circuit breaker may be expected toclose and latch.The maximum permissible interval bet-ween energizing the trip circuit at ratedcontrol voltage and the interruption of themain circuit in all poles.

Rated frequency is the sinusoidal per-iodicity at which the circuit breaker isdesigned to operate.

An elementary diagram providing detailedinformation regarding electrical functionand wiring within the circuit breaker .

Close (Solenoid)Volt Required range of control voltage applied

to the closing solenoid which will ensuresuccessful release of the closing spring.The effective value of current required atnominal control voltage when applied tothe spring release solenoid.

Range

Amps AmpsNominal

Trip (Solenoid)Volt Required range of control voltage applied

to the tripping (opening) solenoid whichwill ensure a successful tripping operation.

Effective value of current required atnominal control voltage when applied tothe tripping (opening) solenoid.

Reference to the instruction manual ap-plicable to the circuit breaker by publica-

tion number.Weight in pounds of the complete circuitbreaker assembly.Specifically identifies an individual breakerand affords traceability to test records andmanufacturing dates.

The month and year within which the circuit breaker was manufactured.

Rated MaxVolts kV

Range

AmpsNominal

Volt RangeFactor (K)

Manual

LBSBIL kV

Serial No.

DateMfg.

Rated ShortCircuit kA

Close & Latch kA SIEMENS Raleigh, NCA.C. High Voltage Circuit BreakerInter Time Cyc.

TYPERATED MAXVOLTS kVRATED SHORTCIRCUIT kA

AMPS _VOLTAGE RANGE.FACTOR KCLOSE &LATCH kA

BILkV

INTERTIME CYCHz

WIRINGDIAGRAMHz

VOLTSRANGEVOLTSRANGEVOLTSRANGE

AMPSNOMINALAMPSNOMINALAMPSNOMINAL

Wiring Diagram MOTOR

CLOSE

Motor (Spring Charging) TRIPVolt Range of control voltages required to

serve the motor which stores energy in theclosing springs.

MANUAL LBS.RangeDATEMFG.SERIAL NO.

Amps Nominal Effective value of current required atnominal control voltage when applied tothe serve the motor which stores energyin the closing springs.

Made in USA 18-658-024-331

Figure 2. Rating Plate




Rating Summary Breaker TypeType-3AFS-circuit breaker designations are normallyarranged in the following format, with significance of each ele-ment indicated:

1. Breaker Type2. Maximum Voltage, kV3 . Continuous Current, AMPS4. Power System Frequency, Hz5. Rated Short Circuit Current , kA6. Voltage Range Factor K7. Interruption Time, Cycles 60 Hz8. Rated Withstand Test Voltage—Low Frequency kV rms9. Rated Withstand Test Voltage—Impulse kV crest10. Closing and Latching Capability (C&L), kA

VV-3AFS-MMMM-AAAA-CC (e.g.: 15-3AF-1000-1200-77)

VV — General voltage class3AFS — Circuit Breaker Design (stationary)

MMMM — Nominal mVA rating followed by alphabeticmodel reference

AAAA — Continuous Current RatingCC — Close and Latch Capability

Table 1. Rating Summary and WeightsWeights, Approximate

Pounds KilogramsWithstand -kV

Cycles Low Freq Impulse RatingC&LKType Vmax

kV AMPS HzI Freq Isc Int t.

kA1096 7 8Numberl 2 3 54

255 1155-3AFS-2505-3AFS-2505-3AFS-3505-3AFS-3505-3AFS-3507-3AFS-5007-3AFS-5007-3AFS-50015-3AFS-50015-3AFS-50015-3AFS-75015-3AFS-75015-3AFS-75015-3AFS-100015-3AFS-100015-3AFS-1000

19 584.76 1200 1.24 3 6060 2911525529 1.24 3 19 60 584.76 2000 60

320 145604.76 1200 60 1.19 3 19 7841320 1457841 ’ 1.19 3 19 604.76 2000 60375 170784.76 3000 1.19 3 19 6060 41

140310668.25 1.25 3 36 951200 60 33310 140668.25 2000 1.25 3 36 9560 33

1703758.25 3000 1.25 3 36 95 6660 331102453715.0 1200 1.30 3 9560 18 361252751.30 95 3715.0 2000 60 18 3 36

310 1405815.0 1200 1.30 3 9560 28 361403102000 1.30 3 95 5815.0 60 28 36

375 1701.30 3 95 5815.0 3000 60 28 36320 14515.0 1200 60 1.30 3 95 7737 36320 14515.0 2000 1.30 3 95 7760 37 36

17538515.0 3000 1.30 3 95 7760 37 36

The values of insulation level compiled in Table 1 arejeferredto sea level in accordance with ANSI C37.04-1979 consolidatedstandards. The higher the site altitude, the lower the insulatingcapacity of the air. The decrease in insulating capacity isneglected by standards for altitudes of up to 3300 ft. (1000m)above sea level. For higher altitudes, the values of low-frequencywithstand voltage, impulse withstand voltage and rated con-tinuous current must be corrected in accordance with Table 1.

Table 2. Altitude Correction Factors, k

Service ConditionsThe following parameters define the usual service conditionsunder which the circuit breakers shall be considered suitablefor operating at their standard ratings. Conditions of use beyondthese limits must be given special consideration, consultationwith the factory or reference to the IEEE Application Guide, ANSIC37.010.

rI f )

Maximum Ambient Temperature = 40 C (104 F)Minimum Amibent Temperature = - 30 C ( - 2 2 F)

3300 Feet (1000 meters)

Unusal service conditions which expose the equipment to dust,steam, salt spray, corrosive gases, dripping water, vibration,shocks, high and low temperatures, high altitude and the likemay require special construction. Refer concerns to the factory.

Altitude RatedContinuous

Current

RatedVoltage

Insulation Levelso

ft. (m) NPAltitude =3300 (1000)

(1500)(3000)

1.00 1.000.995000 0.95

0.80 0.9610000NOTE: Interpolated correction factors shall be used in determining factors for

intermediate altitudes.




General Performance DataTable 3. Operating Times - Typical Values Table 5. Typical Spring Charging Motor Characteristics

Characteristic Control VoltagesANSI C37.06 Tbl. 10

CurrentAmps

Charge TimeSeconds

Cycles 60 Hz ms

Closing TimeOpening TimeArcing Time at 60HzInterrupting Time

4.5 7548 VDC

125 VDC250 VDC120 VAC 60Hz240 VAC 60Hz

8 102.0 336 81 15

833 506 83 8

Table 4. Typical Closing and Tripping Solenoid Charateristics

Control VoltagesANSI C37.06 Tbl.

Trip CoilAmps Ohms Amps

Close CoilTable 6. Auxiliary Switch RatingsOhms

48 VDC125 VDC250 VDC120 VAC 60Hz240 VAC 60 Hz

23 2.1 2.4 20.0 Characteristic Rating121 1.0 23 5.4

Maximum Operating VoltageContinuous Current, Max.Making Current, Max .Breaking Capacity

Resistive Load DC or ACInductive Load at 220VDC(L/R = 20ms)

500 V487 0.5 121 2.110 A121 0.9 23 4.730 A487 0.4 121 1.8

1200 VA

4 750 VA



Interrupter/Operator - Description Page 9

Description—GeneralThe type 3AFS breakers are of stationary construction. Thethree vacuum interruptors, primary insulators and operatingmechanism comprise a unitized "interrupter /operator”assembly (Figure 3).

Current-Path AssemblyThe current-path assembly consists of the upper terminal angle,(27.1) and pole support. (20), the stationary contact, (31) and themoving contact, (36), which is connected with the lower terminal,(29), by terminal clamp, (29.2), and a flexble shunt, (29.1).

Vacuum InterrupterThe moving contacts’, (36), motion is aligned and stabilized byguide bushing, (35). tjhe metal bellows, (34), follows the travel ofcontact, (36), and seals the interrupter against the surroundingatmosphere.

Arc-Quenching PrincipleWhen the contacts separate, the current to be interrupted initiatesan ionized metal vapor arc discharge and flows through this plasmauntil the next current zero. The arc is then extinguished and theconductive metal vapor condenses on the metal surfaces of thearching chamber, (33), (Fig. 6) within a matter of micro-seconds.As a result, the dielectric strength in the increasing contact gapbuilds up very rapidly.

The ensuing descriptive material will discuss the vacuum inter-rupter /operator mechanism assembly in detail.

Description and OperationThe interrupter /operator mechanism assembly consists of thethree breaker poles, each with its vacuum interrupter, mountedon the common motor or hand charged spring stored energyoperating mechanism housing. This assembly is shown in figure3.

ConstructionThe construction characteristics of all vacuum circuit breakerscan be seen in Figs. 3 thru 6. The circuit breaker poles are eachfixed to the rear of the operating mechanism housing, (60), bytwo cast-resin insulators (16). The insulators also connect to theupper (20) and lower (40) pole supports which in turn support theends of the vacuum interrupter (30). Where required by dielect-ric requirements, assemblies are fitted with phase barriers (80).

Below a limit of about 10,000 amperes, the arc is distributed acrossthe contacts and the arc is easily interrupted. At currents largerthan about 10,000 amperes the arcs own electomagnetic forcescause the arc to contract to essentially a point arc. If the contractedarc is allowed to remain stationary, it overheats the contacts at thearc roots to the point where the molten metal vapor does not allowthe dielectric to rebuild during the current zero and large magnitudecurrents could not be interrupted.

The pole supports are aluminum castings on all circuit breakerratings, except for 3000A continuous current where coppercastings are used and on the 15-3AFS-500, 1200A whereformed steel pole supports are used.

The contacts are designed so that a self-generated field causesthe arc to travel around the contacts. This prevents local overheatingwhile interrupting large magnitudes of short circuit current.

The pole support terminals, (27) and (29) each receive primarystud extentions.

The energy-storing mechanism adn all the control and actuatingdevices are installed in the mechanism housing. The mechanismis of the spring charged stored energy type and is mechanical-ly and electrically trip free.

The ionized metal vapor arc discharge can only be maintainedif a certain minimum current flows. A current that does not main-tain this level may be extinguished abruptly prior to current zero.This chopping current must be kept to a minimum in order to pre-vent unduly high overvoltages building up when inductive circuitsare switched, the use of a special contact material ensures thatcurrent chopping is limited to 4-5 Amp.

The close-open indicator (58) closing spring charge indicator55, and the operation counter (59) are fitted on the front of themechanism housing. (Fig. 7)

The rapid build-up of he dielectric strength in the break enablesthe arc to be safely extinguished even if contact separation oc-curs immediately prior to current zero.

The arc drawn inthe vacuum breaker is not cooled. The metal vaporplasma is highly conductive and the resulting arc voltage only at-tains values between 20-200 V. For this reason and because ofthe short arcing times, the arc energy developed in tne break isvery small. This also accounts for the long electrical life expectan-cy of the vacuum interrupter.

The control connector (68.7) for the control and signaling cablesis a 64 contact plug or 24 point terminal block applied internallyto the drawout unit. (Fig 7)

Breaker PoleThe vacuum interrupter (30) is rigidly connected to the upper polesupport (20) by its terminal post (31.2). The lower part of the inter-rupter is stablized against lateral forces by a centering ring (28.1)on pole support (40). The external forces due to switchingoperations and the contact pressure are absorbed by the struts(28).




Descriptions Cont.Legend Figure 3

Owing to the high vacuum (less than 109 bar) in the interrupter,contact clearances in the range of 6 to 11 mm (0.25 to 0.43 in-ches) are adequate to attain a high dielectric strength.

Switching OperationWhen a closing command is initiated the closing spring, which waspreviously charged by hand or by the motor, actuates the mov-ing contact, (36), through breaker shaft, (63), lever, (63.7), insulatedcoupler, (48), and lever, (48.6).

14 Cross-Arm16 Post Insulator20 Upper Pole Support27 Upper Terminal28 Strut29 Lower Terminal

30 Vacuum Interrupter40 Lower Pole Support48 Insulated Coupler49 Contact Pressure Spring50.1 Opening for Hand Crank60 Mechanism Housing

The forces that occur when the action of the insulated coupler isconverted into the vertical action of the moving contact are ab-sorbed by guide link, (48.9), which pivots on pole support, (40)and eyebolt, (36.3).During closing, the tripping spring and the contact pressure springs(49), are charged and latched by pawl, (64.2).

The closing spring of motor-operated breaker is recharged im-mediately after closing.

In the closed state, the necessary contact pressure is maintainedby the contact pressure spring and the atmospheric pressure. Thecontact pressure spring automatically compensates for arc ero-sion, which is very small.

When a tripping command is given, the energy stored in the trip-pign and contact pressure springs is released by pawl, (64.2). theopening sequence si similar to the closing sequence. The residualforce of the tripping spring arrests the moving contact, (36), in theopen position.

Figure 3a. Typical Interrupter/Operator Assembly For5-3AFS-250

Figure 3b. Typical Interrupter/Operator Assembly For 15-3AFS-500, 1200A

Figure 3c. Typical Interrupter /Operator Assembly For OtherRatings




Figure 4. Section Through A Vacuum Breaker Pole

31 Stationary contact31.1 Washer31.2 Stationary Contact Terminal32 Insulator33 Arcing chamber

33.5 Vapor Shield34 Bellows35 Guide36.1 Moving contact stem36.2 Mechanical coupling36 Moving contact

31.2

31.1-fc-

32 5i

Ul3_j131 —J

33 33.5

L 36

d

m34

35 436.1

36.2—1L-IJi Typical forI other ratings Typical for 5-3AFS-250

b.a.

Figure 5. Section through A Typical Vacuum Interrupter Figure 6. Section Through the Typical Vacuum Breakers




Operating Mechanism(Figures 7 thru 11) Construction

The essential parts of the operating mechanism are shown inFig. 7. Its actuation is described under “Flow Chart of OperatingMechanism” in Fig. 12.

Indirect Releases (TnpPin9 Coils)The shunt releases convert the electrical tripping pulse intomechanical energy, it’s function being to release the trippingspring. The undervoltage release may be manually actuated bya make or a break contact. In the make contact case, its coilis shorted out, built-in series resistors limiting the current.

Motor Operating MechanismThe spring charging motor (50.4) is bolted to the chargingmechanism gear box installed in the mechanism housing.Neither the charging mechanism nor the motor require anyservicing.

Auxiliary SwitchThe auxiliary switch (68) is actuated by the breaker shaft.

The operating mechanism is comprised of the mechanical andelectrical components required to:

Charge the closing springs with sufficient potential energyto close the breaker and to store opening energy in the trip-ping and contact pressure springs.

Mechanisms to release closing and tripping actions.

Means of transmitting force and motion to each of three polepositions.

Operate all these functions automatically thru electrical charg-ing motor , cutout switches, anti-pumping relay, releasesolenoids, and auxiliary switches.

Signal thru indicators the breaker status, (open, closed),spring condition (charged or discharged) and number ofoperations.

Mode of OperationThe operating mechanism is of the stored-energy trip free type,i.e. the charging of the spring is not automaticaly followed bythe contacts changing position, and the closing function maybe overridden by a trip command at any time.

When the stored-energy mechanism has been charged, the in-stant of operation can be chosen as desired.

The mechanical energy for carrying out an “open-close-open”sequence for auto-reclosing duty is stored in the closing andtripping springs.

ChargingThe details of the closing spring charging mechanism areshown in Figures 7, 8, 9, & 11. The charging shaft, (62.1), issupported in the charging mechanism, (50.2), but is not coupledmechanically with the charging mechanism. Fitted to it are thecrank, (62.2), at one end and the cam, (62.3), together with lever,(62.5), at the other.

When the charging mechanism is actuated by hand or by amotor , (50.4) the flange, (50.3), turns until the driver, (50.3.1),locates in the cutaway part of cam disc, (62.3), thus causingthe charging shaft to follow. The crank, 62.2, charges the closingspring (62). When this has been fully charged the crank actuatesthe linkage, (55.1), via control lever (55.2) for the “closing springcharged” indicator, (55), and the limit switches, (50.4.1), forinterrupting the motor supply. At the same time, the lever (62.5)

Figure 7. Operating Mechanism Closed Position—ClosingSpring Discharged




Figure 8. Details of Closing Charging Components—Closing Spring Discharged

at the other end of the charging shaft is securely locked by thelatching pawl. When the closing spring is being charged, camdisc, (62.3), follows idly, i.e. it is brought into position for closing.

action by trip command or by means of the racking interlocks.

The trip free coupling rod (62.8) forms a link between the drivelever (62.6) and breaker shaft (63). The rigidity of this linkdepends upon a spring return latch (62.8.1) carried within thecoupling rod. The spring return latch is pivotable within the coup-ling rod and is normally positioned to ensure the couplers rigidity.Link (62.8.2) and trip free coupling lever (62.8.3) cause the springreturn latch position to be dependent upon the breaker’s normaltripping components and the breaker’s racking interlock. Thus,whenever a trip command is applied or the breaker is not in thefully “connected” or test position, the trip free coupling rod is nolonger rigid, effectively decoupling the drive lever and breakershaft. Under these conditions the breaker main contacts can notbe closed.

Closing (See Fig. 7, 8, 9, and 11)If the breaker is to be closed locally, the spring is released bypressing Close button, (53). In the case of remote control theclosing solenoid 52SRC, (53.1), unlatches the closing spring.

As the closing spring discharges, the charigng shaft, (62.1), isturned by crank, (62.2). The cam disc (62.3), at the other endof the charging shaft actuates the drive lever, (62.6), with theresult that breaker shaft, (63), is turned by lever, (63.5), via thetrip free coupling rod, (62.8). At the same time, the lever, (63.1),(63.5) and (63.7) fixed on the breaker shaft operate the threeinsulated couplers for the breaker poles. Lever, (63.7), changesthe open-close indicator over to open. Lever, (63.5), chargesthe tripping spring, (64), during closing, and the breaker is lat-ched in the closed position by lever, (64.3). with pawl roller,(64.3.1), and by pawl, (64.2). Lever (63.1), actuates the auxiliaryswitch, (68), through the linkage, (68.1).

OpeningIf the breaker is to be tripped locally, the tripping spring (64)is released by pressing the trip button, (54). In the case of anelectrical command being given, the tripping solenoid 52T, (54.1)unlatches the tripping spring (64).

The crank, (62.2), on the charging shaft moves the linkage,(55.1), by acting on the control lever, (55.2). The “Closing springcharged” indication is thus cancelled and, the limit switches,(50.4.1), switch in the control supply to cause the closing springto recharge immediately.

Trip Free OperationThe trip free coupling rod, (62.8) permits the immediate decouplingof the drive lever (62.6) adn breaker shaft, (63) to override closing

The tripping spring turns the breaker shaft, (63), via lever, (63.5)the sequence being similar to that for closing.

Rapid Auto-ReclosingSince the closing spring is automatically recharged by the motoroperating mechanism when the breaker has closed theoperating mechanism is capable of an open-close-open dutycycle as required for rapid auto-reclosing.




Manual OperationManually Charging the Closing Spring (Fig. 13)Insert the hand-crank, (50), in hole, 50.1, and turn it clockwiseuntil the indicator, (55), shows Closing spring “CHARGED”.

Electrically operated vacuum breakers can be operated man-ually if the control supply should fail.

Figure 9. Operating Mechanism Open Position—Closing Spring Charged

Figure 10. Breaker Shaft in Open Position—Closing Springs Discharged




Legend Figures 11A-D48 Insulated coupler53 Close pushbutton53.1 Closing solenoid, 52SRC53.2 Spring release latch54 Trip pushbutton54.1 Tripping Solenoid, 52T

62 Closing spring62.1 Charging shaft62.2 Crank62.2.2 Spring mounting62.3 Cam62.5 Lever62.6 Drive Lever62.8 Trip free coupling

62.8.162.8.262.8.362.8.562.8.662.8.762.8.8

Spring return latchTrip free linkTrip free leverPush rod & cam assemblyInterlock lever—push rodInterlock lever—actuatorTrip free actuator (T4.5)Breaker Shaft

63.1 Lever —phase C63.5 Lever—phase B63.7 Lever—phase A

Tripping spring64.2 Pawl64.2.1 Trip latch pin64.3 Lever64.5 Shaft

64

63

Figure 11a. Operating Mechanism Section DiagramOperating Mechanism Open, Closing Springs Discharged(Starreditemschanged from11c on ‘Trip’Operation)(Underlineditemschanged from 11b on ‘Closing Spring Discharge’ Operation)

Figure 11b. Operating Mechanism Section DiagramOperating Mechanism Open, Closing Springs Charged(StarredItemsChangedFrom11don‘Trip’Operation)(Underlineditems changed from 11a on ‘Closing Spring Charge’ Operation)




Figure 11d.Operating Mechanism Section DiagramOperating Mechanism Closed, Closing Springs Charged(Callout items changed from 11c on ‘Closing Spring Charge’Operation)

Figure 11c. Operating Mechanism Section DiagramMechanism Closed, Closing Springs Discharged(Callout items changed from 11b on ‘Breaker Close’ Operation)



Interruptor/Operator - Description Page 17

Closing)(Control voltage applied

Ami-pumping feature (Device 52y)Care must be taken to see tnai a conimuousiy applied closing command doesnot cause ttie breaker to reefose after it has tripped out on a fault, ofherwiseit may sustain damage by the pumping effect

1fSpring ChargingMotor 88Energized

UndervoltageDevice 27*

Picks up

Closing SpringFully Charged Continuous closing command

TTLS3 opens in serieswith anti-pump relay

LS21 and LS22 operTo de-energize springcharging motor 88

LS41 closes to signalclosing springscharged

Closing solenoid, 52SRC, unlatches closing spring andbreaker closes52y

IMotor cutoff switches LS21, LS22 and LS3 are closedbecause closing spring is discharged

-1Breaker

openSpring releasesolenoid actuated thruthe closed 52b contactand two NO contactsof relay 52y

No action.!Open 52b In senes withspring release solenoid(52SRC) blocks springrelease

IClosing commandv when / Before the spring charge motor, 88, has recharged the

closing spring and opened LS3, anti-pump relay 52ypicks up and seals in.

Breakerclosed

Closing springnot charged T

TNo action!Relay 52y picks upthru closed LS3contact and opensspring release circuit

The closing spring isunlatched

The tripping spring ischarged

The anti-pump relay 52y opens two contacts in series withthe spring release solenoid, 52SRC.

I IContacts LS21 andLS22 close to energizemotor 88 LS3 dosesand LS4 opens tocancel closing springsignal

52a contacts in serieswith the trippingsolenoid close toenable a tripoperation

Breaker auxiliaryswitches 52a (NO)and 52b (NC) changestate

The circuit -breakercloses The spring release solenoid is now blocked, and can not

be activated until springs are fully charged and close com-mand is removed.

LThe dashed line shows theoperating sequence initiated byimpairing the closing command.

Rap'd auto-rectosmgThe closing spring is recharged automatically asdescribedabove Therefore,when the breaker is Closed both its springs are charged (the dosing springcharges the tripping spring during closing) As a resull the breaker iscapabfeof an O-f -CO operating cycle idead time i 0 3s)

Tripping•Optional items

iptio^kêviceTrip command

r*CJ>1

f 7Undervoltage device, •27. is activated by /closing NO contapL-/shorting the 22'ooiyJThe NO contact Isconnected across 27 by52a contact thus theNO contact is onlyeffective with breakerclosed

*Undervoltage device.27. is activated byopening a NC contact insenes with 27 or byloss or reduction oftripping voltage

Secondary release. *dual trip function.Activated by remote tripcomand contact NO.

Opening solenoid. 521can only be activatedwhen the seriesconnected 52a contactisclosed

I IUndervoltage deviceOpening solenoid Secondary release *(27)52T »

. unlatches the trippingspring

. . unlatches the trippingspring

. unlatches the trippingspring

T t J

Circuit-breaker trips

Figure 12. Operator Sequential Operation Diagram




Manual ClosingPress the close button, (53), or energize the electrical closingcircuit until the circuit breaker has closed. The closed-open in-dicator , (58), will then display the symbol “CLOSED” anathe closing spring condition indicator will now read“DISCHARGED”.

Manual OpeningThe tripping spring is charged during closing.To open the breaker , press the trip button, (54), or energize theelectrical tripping circuit until the vacuum breaker has trippedand “open” is displayed by indicator , (58).

Elementary DiagramThe closing spring is normally automatically recharged by themotor mechanism immediately after the breaker has closed.

A typical elementary diagram is shown in Figure 14 for DC closeand trip control power. Optional auxiliary switches are shown.

Hand crankOpening for hand-crankciosed buttonTrip button"Closing spring charged" indicatorOpen-Close indicator

5050.153545558

Figure 13. Front View of Mechanism Enclosure Arranged for Manual Operation




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Figure 14. Typical Elementary Diagram

Indirect Releases(Dual Trip and Undervoltage) manual tripping of the circuit breakers by suitable protective

relays or manual control devices when more than one is re-quired. They are generally intended for connection to a separateauxiliary supply (DC or AC).

Undervoltage ReleaseThe undervoltage release is used for continuous monitoring ofthe tripping supply voltage. If this supply voltage falls excessively,the undervoltage release will provide for automatic tripping ofthe breaker.

Refer to Figures 15 and 16

The indirect release provides for the conversion of modest con-trol signals into powerful mechanical energy impulses. It isprimarily used to trip high voltage circuit breakers while func-tioning as a secondary (dual trip) release or undervoltage releasedevice.

These releases are mechanical energy storage devices. Theirinternal springs are charged as a consequence of the breakersmechanism operating, and are released upon application orremoval of applicable control voltages.

The undervoltage device may be used for manual or relay trip-ping by employing a contact in series with undervoltage deviceholding coil. Relay tripping may also be achieved by employ-ing a normally open contact in parrellel with the holding coil.A resistor must be provided to limit current when the normallyopen contact is closed.

Shunt ReleaseShunt releases of type 3AX1101 are used for the automatic or




Construction and Mode of OperationThe release consist of a spring-power storing mechanism, a lat-ching device and an electromagnet. These elements are accom-modated side by side in a housing, (3) (Fig.15) with a detachablecover and three through holes, (5), for mounting screws. Thesupply leads for the trip coil are connected to a terminal block,(33). Two lugs, (17), are fitted beside the tripping pin, (15), forthe attachment of a manual tripping lever.

If the circuit of the trip coil, (7), is interrupted, the armature, 9,drops off , thus causing the latch, (25), to lose its support andrelease the striker pin, (23).

Following every tripping operation the striker pin, (23), must be re-set to its normal position by loading the spring, (31). This takes placeautomatically via the operating mechanism of the circuit breaker.

Since the striker pin of the undervoltage release is latched onlywhen the armature is attracted, this tirp is fitted with a screw,(29)(Fig. 16c), for locking the striker pin, (23), in the normal posi-tion for adjusting purposes or for carrying out trial operationsduring breaker servicing.

The energy-storing mechanism consists of the striker pin, (23),and its operating spring, (31), which is costly located inside thestriker pin (23). When the spring is compressed, the striker pinis held by a latch, (25), whose sloping face is forced againstthe appropriately shaped striker pin, (23). by spring, (27). Theother end of the latch, (25), is supported by a partly milled lock-ing pin, (21) (Fig.16a.), pivoted in the cover sheets of the magnetarmature, (9). The armature, (9), is pivoted in front of the polesof the U-shaped magnet core, (1), and is pulled away from itby the tension spring, (11).

If the magnet coil of the shunt release is energized by the trip-ping impulses or if the tripping pin, (15), is mechanically actuated,magnet armature, (9), is swung against the pole faces, Whenthis happens, the latch, (25), loses its support and releases thestriker pin, (23), which is forced out by the spring, (31).

Figure 16a. Latch Detail Shunt Release (Shown Charged)On the undervoltage release the latch, (25), is held by the lock-ing pin, (21), as long as the armature, (9), is attracted, (Fig. 16b.).

23 25 27

Figure 16b. Latch Detail Undervoltage Release(Shown Charged)

Position A‘Locked’

Position B‘Unlocked’

(Operating Position)AB

29 A i *23B

\Cancel the lock for undervoltage release bymoving locking screw (29) from ‘A’ to *B' 29

Figure 16c. Undervoltage Blocking FeatureFigure 15. Construction of Shunt Release (Shown Released)



Interrupter/Operator - Maintenance Page 21

General Inspection Check ListCheck vacuum, procedures follows.

Check contact erosion, procedure follows.Clean circuit breaker , especially post insulators and in-sulating couplers.Lubricate all bearings and sliding surfaces, procedure andmaterials follow.Check all terminal screws.Check all screw connections and locking devices onmechanism parts.Check all control cables and connections.Perform functional test of circuit breaker.

Thorough, periodic inspection is important to satisfactory opera-tion. Inspection and maintenance frequency depends on instal-lation, site, weather and atmospheric conditions, experience ofoperating personnel and special operation requirements.Because of this, a well-planned and effective maintenance pro-gram depends largely on experience and practice.

1 .

2.

3.

4 .

FAILURE TO PROPERLY MAINTAIN THE EQUIPMENT CANRESULT IN SEVERE PERSONAL INJURY AND PRODUCTFAILURE. THE INSTRUCTIONS CONTAINED HEREIN SHOULDBE CAREFULLY REVIEWED, UNDERSTOOD AND FOLLOWED.THE FOLLOWING MAINTENANCE PROCEDURES SHOULD BEPERFORMED REGULARLY:

• General visual inspection of de-energized circuit breaker.• Keep mechanism clean and adequately lubricated.

• Keep insulation materials dry and clean.

• Keep connectors in place and properly adjusted.• Repair or replace any items functioning improperly.• Check circuit breaker for smooth and correct operation

before returning to service.Annually, a general visual inspection should be performed onde-energized breakers. Where the application imposes dustyor other severe ambient conditions and/or frequent switchingoperations the following inspection checks should be more fre-quently applied than for normal maintenance.

5.6.

7.8.

Hand Tools RecommendedThe 3AFS breakers employ both English and Metric fasteners.Metric fasteners are confined to the circuit breaker subassembly.The supporting drawout vehicle uses English sizes. The followingtool list has been prepared primarily to identify the tool require-ments normally expected.

General• Screw Drivers, 0.032 x 1/4 and 0.055 x 7/16

• Pliers• Light Hammer• Drift Pin, 1/8, 3/16, 1/4

• Retaining Ring Plier; External Type Tip Diameter 0.040 "

THESE INSTRUCTIONS DO NOT REPRESENT AN EXHAUSTIVESURVEY OF MAINTENANCE STEPS NECESSARY TO ENSURESAFE OPERATION OF THE EQUIPMENT. PARTICULAR AP-PLICATIONS MAY REQUIRE FURTHER PROCEDURES.SHOULD FURTHER INFORMATION BE DESIRED OR SHOULDPARTICUALR PROBLEMS ARISE WHICH ARE NOT COVEREDSUFFICIENTLY FOR THE PURCHASER’S PURPOSES, THEMATTER SHOULD BE REFERRED TO THE LOCAL SIEMENSSALES OFFICE.

Metric• Sockets and Open-end Wrenches:

7mm, 8mm, 9mm, 10mm, 11mm, 13mm, 17mm19mm, 24mm

• Hex Key:THE USE OF UNAUTHORIZED PARTS IN THE REPAIR OF THEEQUIPMENT OR TAMPERING BY UNQUALIFIED PERSONNEL,WILL RESULT IN DANGEROUS CONDITIONS WHICH CANCAUSE SEVERE PERSONAL INJURY OR EQUIPMENT DAM-AGE. FOLLOW ALL SAFETY INSTRUCTIONS CONTAINEDHEREIN.

2mm, 5mm, 6mm, 8mm, 10mm• Torque Wrench, 0-150Nm (0-100Lb. Ft.)

English• Sockets and Open-End Wrenches:

5/16, 3/8, 7/16, 1/2, 9/16, 3/4, 7/8

A WARNINGh • Hex Key:3/16, 1/4

Hazardous voltages and high speed mechan-ical parts can cause death or severe personalinjury and property damage.

Read instruction manual, observe safety in-

structions and limit use to qualified personnel.




Minimum Maintenance ScheduleThe Maintenance intervals indicated in Table 7 are for equip-ment installed in accordance with “Usual" operating conditionsas defined by ANSI. If ‘Unusual’ operating conditions are ex-perienced by the equipment, the operating intervals betweenmaintenance should be reduced as required for thoseconditions.

Table 7. Maintenance Intervals Under ‘Usual’ OperatingConditions per ANSI C37.04Minimum Maintenance Interval Close Operation

Close OperationType Breaker Lubrication Overhaul5-3AFS-2505-3AFS-3507-3AFS-500

15-3AFS-50015-3AFS-75015-3AFS-1000

10000 300001000030000300003000010000

Lubrication:

The operating mechanism should be oiled and lubricated at leastevery 10 years or within the operations interval indicated in Table7, whichever occurs first.

30001000010000100003000

Overhaul:

Within the operations interval indicated in Table 7, the circuitbreaker should be maintained in accordance with the followingrecommendations and the following components replaced:

• Vacuum Interrupters• Closing Solenoid, 52SRC• Opening Solenoid, 52T• Trip Free Drive Bar Mechanism

Lubrication of the OperatingMechanism

A WARNING

h Hazardous voltages and high speedmechanical parts can cause death, personalinjury and property damage.Before starting any work, breaker should beisolated, short circuited and grounded. Con-trol power should be disconnected andbreaker closed and opened by hand untilboth springs have been discharged.

When these parts are changed, locking devices must also beremoved and replaced. These include lockwashers, retainingrings, retaining clips, spring pins, cotter pins, etc.




The main points to be lubricated with grease (bearings andsliding surfaces) are indicated in Fig. 17. All the points notmarked (bearings, articulated joints and auxiliary switch) shouldbe treated with light machine oil with rust inhibitor.

Lubricating Materials:

Bearings and Sliding SurfacesBeacon 325, Humble Oil and Refining Co., or15-337-131-001Centoplex 24.DL, Klueber Lubrication Corp.

Grenier Industrial Park, Manchester, N.H. 03103To relubricate the mechanism remove the cover. Lubricate allthe appropiate points starting at the top left and working throughsystematically. Parts that are not rigidly fixed (e.g. articulatedjoints) should be moved slightly to and fro to let the oil penetrate.Following this, operate the breaker several times to test it.

Pivots and Articulated Joints, Auxiliary Switches, etc.Tectyl 910 Valvoline Oil Co., Division of Ashland

Oil Inc.Ashland Dr., Ashland, Ky. 41101

SAE #10 Motor Oil with rust inhibitors.

Articulated joints and bearings that cannot be dismantled shouldnot be cleaned with a cleaning agent prior to being oiled.

See Vehicle Lubrication section for additional information.

Figure 17. Operator Lubrication Points




Hydraulic Shock AbsorberThe 3AFS mechanism is equipped with a hydraulic shockabsorber and a stop bar that functions when the breaker opens.See item 61.8 Figure 9. The shock absorber should require noadjustment. Flowever, at maintenance checks, the shockabsorber should be examined for evidence of leaking. If evi-dence of fluid leakage is found, the shock absorber must bereplaced to prevent damage to the vacuum interrupter bellows.

Life = Interruptions x Current

They must also be replaced before 30,000 mechanical opera-tions or when the contacts have been erroded beyond allowedlimits. Vacuum tube replacement procedures are detailed in thefollowing maintenance instructions.

As a guide to life expectancy the curves in Figure18 are offered.

Vacuum InterruptersLife Expectancy

3AFS BreakerDesignation

Volts kV 5- 5- 7- 15« 15- 15-

Nom.mVA 250 350 500 500 750 1000Rated Max. Volts, kV 4.76 8.25 15.0

The life expectancy of vacuum interrupters is a function of thenumber of interruptions and magnitude of current interrupted. Rated Short-Circuit

Current, kA29 41 33 18 28 37

Rated ContinuousCurrent, A

1200 b fdca e20003000

fb da c eb fc e

Applicable Curve a Function of Breaker Rating

Contact ErosionVacuum interrupters should be checked periodically for con-tact shortening, which is normally associated with erosion of con-tact material during high fault current interruptions. Contactshortening or erosion is normally not expected to be significantuntil the number of operations indicated for contact life is ap-proached. When the number of operations reaches the indicatedcontact life or excessive contact shortening or erosion is in-dicated, the interrupter tubes should be replaced. Contact ero-sion or shortening normally is checked by the visibility of theerosion mark. Alternately it may be checked by measuring thecontact stroke.

Contact erosion is checked on a closed breaker by visuallyobserving a white dot erosion mark (A) on the exposed movablecontact stem of the interrupter, see Figure 19.

NOTEThe tripping springs are charged and the circuitbreaker could open unexpectedly.

The mark (A) may be seen above the lower primary connec-tion, and just above the terminal clamp which fastens the flexi-ble connector (29.1) to the movable stem of the vacuum tube.

The criteria of acceptance is that as long as the white erosionmark or any part of it can be seen with the breaker closed, con-tact wear is within permissible limits.Figure 18. Typical Primary Interrupter Contact Life Curves




Interrupter Vacuum Check—Mechanical(Refer to Figures 20a, 20b, & 20c)

Checking the Vacuum

Contact stroke measurement may be made by the proceduresdescribed in paragraph 3.0. ‘Checking the Contact Stroke’ under‘Vacuum Tube Replacement’ later in this section.

Before putting the breaker into service, or if an interrupter issuspected of leaking as a result of mechanical damage, checkthe vacuum as follows:

Figure 20a. Lower Pole Support With Insulated Coupler

Open and isolate the breaker and detach the insulated coupler48, from lever, 48.6, Fig. 20a.

The atmospheric pressure will force the moving contact of ahermetically sealed interrupter into the "Closed” position, caus-ing lever, 48.6, to move into the position shown in Fig. 20b.

Figure 19. Contact Erosion Check

Adjustment of the contact gap may be necessary on higher in-terrupting capacity circuit breakers which are subjected torepeated high fault current interruptions. These proceduresshould be used at least each time a high interrupting capabilitycircuit breaker, interrupter experiences about 25% of expectedlife under full high fault current interruptions. The type 5-3AFS-350 and type 15-3AFS-1000 circuit breakers should be checkedat approximately 4 full fault interruptions, for example. If the strokeis not in the proper range it should be brought back into properadjustment using the procedures described in paragraph 3.0.

A vacuum interrupter may be assumed to be intact it shows thefollowing characteristics:

An appreciable closing force has to be overcome when lever,48.6, is moved to the "Open” position by hand, Fig. 20c. Whenthe lever is released, it must automatically return to the "Closed”position with an audible sound as the contacts touch.After checking the vacuum, reconnect the lever, 48.6, to theinsulated coupler 48.




Figure 20b. Primary Contact Closed - Free Position

High Potential Testing and Electrical InterrupterVacuum CheckHigh Potential tests are performed to affirm the breakers dielec-tric integrity, and to establish be alternate means of checkingthe interrupters vacuum.

Figure 20c. Primary Contact Forced Open by Manual Pressure

Prior to applying the test voltage, each pole not under test shallbe grounded. Apply test voltage for one minute. If no disrup-tive discharge occurs which permanently reduces the testvoltage to zero, the primary insulation system is acceptable.

1 1

A DANGER Interrupter vacuum may be checked by applying the testvoltages listed across each interrupter with the breaker open.Test voltage should be raised gradually , and the contact gapmust sustain the voltages listed below, appropriate the breakersrating, for one minute. If it does not, the interrupter is faulty andmust be replaced.h High Potential Tests employ extremely hazar-

dous voltages which will cause severe per-sonal injury and death.Follow safe procedure, exclude unnecessarypersonnel, barrier test vehicle and keep wellaway from breaker during test voltage ap-plication. After test, ground ends and middleof vacuum tube to remove static charge. A CAUTION

h Erroneous test results may occur. Vacuum in-terrupters can emit X-Radiation causing per-sonal injury.Many DC high potential machines arehalfwave rectifiers. This type of HiPot testermust not be used to test vacuum interrupters.

The capacitance of the interrupter is very lowand the leakage in the rectifier and its DCvoltage measuring equipment is such that thepulse from the half wave rectifier may be ap-proximately 120k V when the meter is actuallyreading 40k V. In this case, good interruptersmay show a relatively high leakage currentsince it is the peak voltage of 120k V that isproducing erroneous leakage current. In ad-dition, abnormal X-Radiation may beproduced.

A CAUTION

h Vacuum Interrupters can emit X-Radiationcausing personal injury.

Do not apply test voltages to the interrupterswhich exceed the values listed below. Testpersonnel must remain a minimum of six feetaway from interrupter under test.

The primary insulation system fo the circuit breaker may bechecked by closing the breaker, and applying the voltages listedbelow between a primary conductor of each pole and ground.

D.C. PotentialA.C. PotentialBreaker Max. KV2014KV

27 KV5 KV

7 & 15KV 38



Interrupter/Operator - Vacuum Interrupter Page 27

Vacuum Tube Replacement1.6 Lossen screws fastening the centering ring, 28.1.

(10mm open end)1.7 Remove bolt “B”, lockwasher and large washer at sta-

tionary contact of the vacuum interrupter. (24mm socket).Carefully note location of conductive spacers betweeninterrupter and pole support.

1.8 Using a deep 24mm socket loosen and remove hexcapscrew fastening the upper pole support to the postinsulator. Completely remove the upper pole supportand set aside.

1.9 Grasp the vacuum interrupter and withdraw vertically.Assistance may be required to work the terminal clampoff the movable stem of the tube. FORCIBLE TWISTINGEFFORT IS NOT ALLOWED. If the terminal clamp can-not be easily removed, STOP!, check to be certain hard-ware is loose and the clamp is not bound.

2. Installing the Interrupter

Replacement interrupters are furnished as a complete assembly.They have been completely tested and dielectrically andmechanically conditioned. The interrupters, when installed, donot require that they be operated no-load a set number of timesor voltage tested to condition the contacts.

It is recommended that one interrupter be removedand replacedcompletely rather than removing two or more interrupters at atime. The following procedure in check list format describes theprocedure for removing and replacing a vacuum interrupter.Components may be identified by reference to Figures 4, 5, 21 &22.

1. Removing The Interrupter

1.1 Before starting work, the circuit breaker should be iso-lated from all primary and control power sources and allstored energy discharged by tripping, closing, and trip-ping the breaker by hand. Discharge any static chargeby grounding all end and center metal sections of thevacuum interrupter. Carefully remove interphase barriers.

NOTEA WARNING Replacement interrupter, 30, will be received from the

factory with an eyebolt, 36.3, in place, adjusted andtorqued to specific requirements. DO NOT ALTER THEEYEBOLT SETTING.h Hazardous voltages and high speed mec-

hanical parts can cause death, personal in-jury and property damage.

Before starting any work, breaker should beisolated, short circuited and grounded. Con-trol power should be disconnected anbreaker closed and opened by hand untilboth springs have been discharged.

2.1 Inspect all silver plated connection surfaces for clean-liness. Clean only with a cloth and solvent. Do not abraid.

2.2 Insert interrupter, 30, in the lower pole support, 40, withthe evacuation nipple ‘P’ facing the mechanism hous-ing. Slip terminal clamp, 29.2, into position on themovable stem.

2.3 Restore any conductive spacers which may have beenprovided to span the space between tube and pole sup-port. Locate the upper pole support and fasten '‘fingertight” using heavy flat washer, lockwasher and bolt, ‘B’.

2.4 Fasten the upper pole support to the post insulator us-ing finger pressure only using hex head bolt, lockwasherand flat washer.

2.5 Attach struts, 28, to the upper pole support, 20, replacehardware, but do not tighten at this time.

2.6 Couple lever, 48.6, and drive link, 48.9 to the eye, 36.3,using the pin supplied. Apply retention clips. Appropriatepin is modestly chamfered, not to be confused with pinfor the insulated coupler.

2.7 Elevate terminal clamp, 29.2, against the locking ringon the movable terminal of the vacuum tube, 36.1 andposition the interrupter 30, so that its groove faces theconnecting surface of flexible strap 29.1. Refer to Figure22 and employ technique illustrated to fasten terminal

1.2 Loosen the lateral bolt(s) on terminal clamp. 29.2. Referto Figure 22 and employ the illustrated procedure toloosen clamp hardware. (8mm hex alien and 17mmsocket)

1.3 Withdraw pin, 48.5, from insulating coupler, 48, andlever, 48.6.

1.4 Remove coupling pin from the eye bolt , 36.3.1.5 Free struts, 28, from the upper pole support, 20. Loosen

the strut hardware on the lower support, 40, and swingthe struts forward and downward. (17mm open end and17mm socket)

NOTESome breakers may employ four struts. The ad-ditional struts should also be freed from the up-per pole support, loosened at the lower pole sup-port and swing the struts rearward and downward.




Figure 21. Vacuum Tube Replacement Illustration




Figure 22. Illustration Showing Required Technique For Fastening Terminal Clamp Hardward

clamp. Note opposing wrenches. Tighten the bolt(s)of the terminal clamp to a torque of 30 ± 4 Lb. Ft.(40Nm), taking care to see that the copper terminal ofthe interrupter is not subjected to excessive bendingmoments.

2.8 Align pole support, 20, correctly and tighten bolt fasten-ing it to the post insulator. Fasten securely all boltsassociated with struts, 2.8.

2.9 Tighten interrupter fastening bolt ‘B’ on the upper polesupport, 20, holding the interrupter firmly by its upperinsulator, and operate levers, 48.6, by hand to seewhether the movable contact moves freely. If any bind-ing or lack of freedom is noted, loosen bolt ‘B’ and ad-just the interrupter in pole support by turning and mov-ing it slightly.

2.10 Press centering ring segments firmly against base oftube, and fasten securely . On some breaker a one piecering is used, and this is simply fastened in place.

NOTEExcessive bending movement exerted while fasteningthe terminal clamp will damage the vacuum interrupter.




2.11 Attach insulating coupler, 48, and lever, 48.6 togetherusing pin 48.5. Apply retaining clips. Correct pin hasends which have been generously chamfered.

2.12 Open and close breaker several times, and then checkto see that all bolted joints and sevices are tight.

3 . Checking the Contact Stroke

3.1 Open the circuit breaker.

3.2 Free insulating coupler, 48, by removing pin 48.5. Theinterrupter contacts most now close automatically as aconsequence of atmospheric pressure.

3.3 Observe the terminal clamp, 29.2 thru the openings oneach side of the lower pole support, 40. Using verniercalipers measure the distance "X”, from the bottom sur-face of the terminal clamp to the bottom edge of thecutout opening. Measure carefully , and record yourresult.

3.4 Connect the insulating coupler, 48, using pin,48.5, andthe retaining clips provided.

3.5 Repeat the measurement described in item 3.3 againwith care to maximize accuracy, record your result, “X2”.

3.6 Determine difference (X, - X2) between the measure-

ments made under items 3.3 (X^ and 3.5 (X2). Your resultshould be:

• Type 5-3AFS-250 Breakers 5 to 7mm (0.20 to 0.27inches)

• Type 7-3AFS-500A, 15-3AFS-500 and15-3AFS-750breakers 10 to 12mm (0.40 to 0.47 inches)

• Type 5-3AFS-350, 15-3AFS-1000 and all 3000Abreakers 7.5 - 8.5mm (0.30 - 0.33).

3.7 If you fail to achieve the listed results carefully repeatthe entire procedure making certain of yourmeasurements.

3.8 If after confirming your measurements, you find thestroke not in agreement with the values given above,an adjustment can be made by adjusting the eyebolt,(48.6) at the end of the insulated coupler 48.

NOTEDo not adjust eyebolt 36.3 on interrupter .

• Excessive stroke is corrected by turning the eyeboltout.

• Insufficient stroke is corrected by turning the eyeboltin.

3.9 Loosen locking nut on eyebolt on insulated coupler (48),and retain position of the eye. Make adjustments in one-half turn increments. After adjustment is completed,tighten eyebolt locking nut to 30 ± 4 Lb. Ft. (40 ± 5Nm).

4. After eyebolt is tightened to proper torque, repeated allmeasurement procedures making certain they are in agree-ment with values indicated in 3.6.4.1 Complete all other maintenance procedures complete-

ly reassembled breaker should pass high potential testbefore it is ready for service.

Solenoid ReplacementReplace closing solenoid, 52SRC, and opening solenoid, 52T.• Remove two “push on’ ’ terminal connections.• Remove two M4 hex head screws and dismount solenoid

drawing it towards you.• Install replacement solenoids with two M4 hex head screws

and replace “push on’ ’ terminals.

• Apply a thread locking adhesive to solenoid screws, Loctititetype 222 recommended.

Operational CheckWhen work is finished operate circuit breaker , close open,several times, and check that all screw connections are tight.



Warranty Page 31

Siemens warrants title to the product(s) and, except as notedbelow with respect to items not of Siemens’s manufacture, alsowarrants the product(s) on date of shipment to Purchaser , tobe of the kind and quality described herein, merchantable, andfree of defects in workmanship and material.

This warranty is expressly in lieu of all other warranties, in-cluding but not limited to implied warranties of merchantabilityand fitness, and constitutes the only warranty of Siemens withrespect to the product(s).

If within one year from date of initial operation, but not more thaneighteen months from date of shipment by Siemens of any itemof product(s), Purchaser discovers that such item was not aswarranted above and promptly notifies Siemens in writingthereof , Siemens shall remedy such nonconformance by, atSiemens's option, adjustment or repair or replacement of theitem and any affected part of the product(s). Purchaser shallassume all responsibility and expense for removal, reinstalla-tion, and freight in connection with the foregoing remedies. Thesame obligations and conditions shall extend to replacementparts furnished by Siemens hereunder. Siemens shall have theright of disposal of parts replaced by it.

Any separately listed item of the product(s) which is notmanufactured by Siemens is not warranted by Siemens, andshall be covered only by the express warranty, if any, of themanufacturer thereof.

This states purchaser’s exclusive remedy against Siemensand its suppliers relating to the product(s), whether in con-tract or in tort or under any other legal theory, and whetherarising out of warranties, representations, instructions, installa-tions or defects from any cause. Siemens and its suppliers shallhave not obligation as to any product which has been improperlystored or handled, or which has not been operated or main-tained according to instructions in Siemens or supplier furnishedmanuals.



Siemens Energy& Automation, Inc.P.O. Box 29503Raleigh, NC 27626(919) 365-6660

SIEMENS

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SG3398 1M 4/91 PRINTED IN U.S.A.



Documents

Type-3AFS Instructions Installation VacuumCircuitBreakers