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SIEMENS

Type-3AFVacuum Circuit Breakers5-3AF-250A, 5-3AF-350A, 7-3AF-500A15-3AF-500A, 15-3AF-750A and 15-3AF-1OOOA

InstructionsInstallationOperationMaintenanceSG-3158-01

www.nationalswitchgear.com

Courtesy of NationalSwitchgear.com

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.

A DANGER

h Power 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, aqualifiedperson 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 or

substantial 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 Data

Interrupter/Operator - DescriptionDescription—GeneralDescription and Operation

ConstructionBreaker PoleCurrent-Path AssemblyVacuum InterrupterThe Arc-Quenching PrincipleSwitching Operation

Operating MechanismConstructionIndirect ReleasesMotor Operating MechanismAuxiliary Switch

Mode of OperationChargingClosingTrip Free OperationOpeningRapid Auto-Reclosing

Manual OperationManually Charging The Closing SpringManual Closing

Interrupter/Operator (con’t)Manual Opening

Elementary DiagramIndirect Releases

Shunt ReleaseUndervoltage ReleaseConstruction and Mode of Operation. .

Interrupter/Operator - MaintenanceGeneralInspection ChecklistHand Tools Recommended

GeneralMetricEnglish

Minimum Maintenance ScheduleBarrier CleaningLubrication 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

Vehicle - DescriptionDescriptionAlignmentInterlocks

Closed Breaker Racking Interlock. . . .Trip-Free InterlockAutomatic Closing Spring Release. . . .

Connection to Secondary Disconnects. .Vehicle - Maintenance

Vehicle LubricationWarranty

21002102

03 2222224234

5245246242482492492592510252711

11 2711 2713 281313 2913 3013 3315 331515 3415 3415 3415 3715 3816 3916 391616

401717 4121

NOTEThe instructions contained within this manual arenecessary 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.



General Page 1

*

Figure 1a. Type 3AF Vacuum Circuit Breaker—Front View.V*



General Page 3

Figure 1c. Type 15-3AF-500A Circuit Breaker in Test/Disconnect Position.



Interrupter/Operator - Description Page 13

Descriptions Cont.Breaker Pole The rapid build-up of he dielectric strength in the break enables

the arc to be safely extinguished even if contact separation oc-curs immediately prior to current zero.The vacuum interrupter (30) is rigidly connected to the upper pole

support (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

The arc drawn inthe vacuumbreaker 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 teh break isvery small. This also accounts for the long electrical life expectan-cy of the vacuum interrupter.

(28).

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. 7) within a matter of micro-seconds.As a result, the dielectric strength in the increasing contact gapbuilds up very rapidly.

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 OperationWhena 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).

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.

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.

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.

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 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.

"'X




Manual OperationManually Charging the Closing Spring (Fig.12)Electrically operated vacuum breakers can be operated man-

ually if the control supply should fail. Insert the hand-crank, (50), in hole, 50.1, and turn it clockwiseuntil the indicator, (55), shows Closing spring “CHARGED”.

50.3 Charging FlangeDriverClose buttonTrip buttonClosingspring"Charged-Discharged’Open-Close indicatorOperation CounterShock AbsorberClosing springCamLeverPaw* tollerPaw.Breaker ShaftTripping Spring

50.3.1535455585961.86262.362.562.5.162.5.2636464.2 Pawl64.3 Lever

Pawl rollerTrip Free Actuator (T4.5)

64.3.162.8.8

Figure 10. Operating Mechanism Open Position—Closing Spring Charged

Figure 11. Breaker Shaft in Open Position—Closing Springs Discharged



Interrupter/Operator - Description Page 19i

Figure 12d. Operating Mechanism Section DiagramOperating Mechanism Closed, Closing Springs Charged(Callout items changed from 12c on 'Closing Spring Charge'Operation)

Figure 12c. Operating Mechanism Section DiagramMechanism Closed, Closing Springs Discharged(Callout items changed fron 12b on 'Breaker Close' Operation)




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" andthe 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 15 for DC closeand trip control power. Optional auxiliary switches are shown.

Figure 14. Front View of Mechanism Enclosure Arranged for Manual Operation\




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 ahousing, (3) (Fig. 16) 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. 17c), 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. 17a.), 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).

2723 25

eIf 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).

O& u/

21

Figure 17a. 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. 17b.). 23 25 27

Bja3

Figure 17b. Latch Detail Undervoltage Release(Shown Charged)

Position A‘Locked’

PositionB‘Unlocked’

(Operating Position)23^ It4

23-^ kA29

29Cancel the lock for undervoltage release bymovinglocking screw (29) from *A* to *B'

Figure 16. Construction of Shunt Release (Shown Released) Figure 17c. Undervoltage Blocking Feature



Interrupter/Operator - Maintenance Page 25

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.

POPULAR CLEANING AND DEGREASING AGENTS SUCH ASTHE CHLORINATED HYDROCARBONS TRICHLOROETHY-LENE, PERCHLORORTHYLENE, AND CARBON TETRA-CHLORIDE, MARKETED UNDER A LARGE NUMBER OFTRADE NAMES, MAY CRACK, CRAZE OR OTHERWISE ATTACKTHE BARRIER. THEY MUST NOT BE USED FOR CLEANINGOR DEGREASING. NOR SHOULD AROMATIC COMPOUNDSSUCH AS BENZENE, XYLENE, OR TOLUENE BE USED.Recommended for cleaning the Barrier are soap and water;No.1 and No.3 denatured alcohol; white kerosene; Varsol No. 2;VM&P naphtha; heptane; hexane; isobutyl and isopropylalcohol.

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

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

When these parts are changed, locking devices must also be) removed and replaced. These include lockwashers, retaining

rings, retaining clips, spring pins, cotter pins, etc.

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

Close OperationType Breaker Lubrication Overhaul

5-3AF-2505-3AF-3507-3AF-500

15-3AF-50015-3AF-75015-3AF-1000

10000 300001000030000300003000010000

Molded Barrier and Interphase Barrier Mounting3000100001000010000 Lubrication of the Operating

Mechanism3000

A WARNINGBarrier Cleaning

* 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.

A CAUTIONh The Barrier has been molded in a phenyleneether copolymer alloy. This high quality elec-trical grade polymer requires special care inthe choice of cleaning agents. Please ob-serve the following advisory.




Hydraulic Shock AbsorberThe 3AF mechanism is equipped with a hydraulic shock ab-sorber and a stop bar that functions when the breaker opens.See item 61.8 Figure 11. The shock absorber should requireno adjustment. However, at maintenance checks, the shock ab-sorber should be examined for evidence of leaking. If evidenceof fluid leakage is found, the shock absorber must be replacedto prevent damage to the vacuum interrupter bellows.

Life = Interruptions x CurrentThey 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 Figure 19 are offered.

Vacuum Interrupters3AF BreakerDesignation

Volts kV 5- 5- 7- 15- 15- 15-Nom.mVA 250 350 500 500 750 1000Life Expectancy

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

Rated Max. Volts, kV 4.76 8.25 15.0Rated Short-CircuitCurrent, kA

29 41 33 18 28 37

Rated ContinuousCurrent, A

b1200 d fea cb2000 d fea cb3000 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 thenumber 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 20.

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 19. Typical Primary Interrupter Contact Life Curves




Figure 21b. 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 21c. Primary Contact Forced Open by ManualPressure

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.

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-terrupterscanemit 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 CAUTIONh 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,andapplying the voltages listedbelow between a primary conductor of each pole and ground.

Breaker Max. KV A.C. Potential D.C. Potential5 KV

7 & 15KV14KV27 KV

2038



Interrupter/Operator - Vacuum Interrupter Page 31

\

/ Figure 22. Vacuum Tube Replacement Illustration



1nterrupter/Operator - Vacuum Interrupter Page 33

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. The

interrupter 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 (XT - X2) between the measure-ments made under items 3.3 (X^ and 3.5 (X^. Your resultshould be:• Type 5-3AF-250 Breakers 5 to 7mm (0.20 to 0.27

inches)

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

• Type 5-3AF-350, 15-3AF-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, Loctitite

type 222 recommended.

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



Vehicle - Description Page 35

/I

'

Figure 24A. Drawout Truck Sub-assembly Showing Major Cubicle Interface Items




Closed Breaker Racking Interlocks Inside the cubicle, the raised blocking arm is held by the rec-tangular slot of the interlock plate assembly and the closed cir-cuit breaker cannot be moved out of either the ‘connect’ or‘test/disconnect’ positions, with the circuit breaker closed, theinterlock plate assembly holds a shield (42 Fig. 26) over the hex-head drive nut (43 Fig. 26) on the shaft of the screw rackingmechanism. When held in place, the shield prevents the rackingcrank from being engaged and the breaker can not be moved.

The racking interlock is the combination of a block arm (T5) onthe right side of the circuit breaker and an interlock plateassembly (55 Fig. 25) mounted on the right side of the cubicle.This combination blocks engagement of the racking screw drivemechanism unless the circuit breaker is open and preventsmovement of a closed circuit breaker in its cubicle.

When the circuit breaker closes, a lever (T5.3) on the breakershaft (63) causes the blocking arm (T5) to be raised, where itremains until the circuit breaker is opened, if the circuit breakeris closed outside of its cubicle, the raised blocking arm allowsonly partial insertion into the cubicle.

Three holes (44 Fig. 26) for padlocks are included on the rackinginterlock assembly, which can keep the shield over the hex-headdrive nut on the shaft of the screw racking mechanism. With apadlock in place, racking of the circuit breaker will be prevented.This may be desired during maintenance or other operations.

41 55

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i + [LED jSs cz~yffl 43m c.ff i

•4— * T

Ly{ i

3 II1 © 44

e±Le

25

-0-^^ ^Ip- i -frn i iiUi u/•?*

LJVIEW OF RIGHT SIDEOFCUBICLE

1. Screw racking mechanismassembly

4. Racking Latch25. Racking Key Interlock29. Racking Interlock Plate

42. Shield43. Hex Head Drive nut44. Padlock hole.55. Racking Interlock Plate

Assembly

*s

Figure 25. Closed Breaker Racking Interlock Plate Assembly (Superimposed over screw racking mechanism)




Connection to SecondaryDisconnects

Automatic Closing Spring ReleaseRecommended normal procedure for circuit breaker withdrawalfrom the test/disconnect positon includes:(1) Disconnect control power supply, and then (2) Dischargestored energy springs in the circuit breaker (pushing trip, thendose and then trip pushbuttons).

The 3AF type circuit breakers employ a cable which completesall standard circuit breaker electrical connections between theplug in cable connector “XO" at the mechanism housing andthe vehicles secondary disconnects. ‘SDA’ (and ‘SDB’ whenused). Figure 28 provides the detail of the control cable wiringfor the typical schematic diagram shown in Figure 15. TypicalElementary Diagram’, when 64 contact plug is used.

Where the recommended normal withdrawal procedure is notfollowed, and automatic closing spring release feature will func-tion. This is to ensure that all spring energy in the mechanismhas been discharged prior to the circuit breakers removal from(or insertion into) the cubicle.

Refer to the contact drawing for specific details.

"XO"A c 0B

Stored energy springs are discharged if withdrawal is attemp-ted prior to performing the steps in the recommended normalprocedure listed in the first paragraph of this section. The follow-ing actions will occur as the circuit breaker moves past thetest/disconnect' position:

)1rz

V Jr

3y \'I

‘4 V > vS yv1. Secondary disconnects immediately open. The sliding secon-

dary disconnect is at the end fo its stroke and the contactsautomatically separate upon further withdrawal.

2. Circuit breaker moves to trip-free condition and then closingsprings are discharged. Spring discharge is caused by theroller arm (T4.1) moving out the ‘vee’ groove and up an ac-tuating angle on the wall of the cubicle to the high rail. Thehorizontal movement of the roller arm (about .62 in./16mm)is amplified by the lever arrangement (T4) to a vertical move-ment of the trip-free push rod and cam assembly (62.8.5)(approximately 1.25in./32mm).The vertical movement of thetrip-free' push rod and cam assembly first operates the trip

latch (62.8.3) and then the spring release latch (53.2) to com-plete the spring discharge action. (See Figure 24 & 26).

r6

“7

8

<><r9Nr-S

16 V >r

117"

12r.13

14 ^ > y

*6?IS

s. v —./i

16

X 24 conductor cable

"SOB""SDA"The tripping springs are always discharged when the circuitbreaker is open and a special discharge mechanism is notnecessary.

o o o o oo o o3 6 9 12

61 04 07 O103 6 9 12

01 07 O10048 112 S 2 11S 8

O o o o o o o o

Secondary Disconnect

Figure 27. Secondary Disconnect Wiring

i



Warranty Page 41

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 produces), 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.



Vehicle - Maintenance Page 40

Vehicle LubricationReference Figures 1B and 24.

Primary contacts (multi-fingered clusters) and secondary discon-nects (Plugs—SDA and SDB) are to be wiped clean and a filmof Siemens contact lubricant applied, 15-171-370-002. Controlconnectors are normally not disconnected and lubrication shouldnot be required. They may be lubricated in the same manneras secondary control contacts.

Sliding surfaces such as shutter cam, rail plunger, etc., maybe wiped clean and treated with "Molycote Penelube",15-171-270-002.

Nylon sliding and rotaitonal bearings require no lubrication.

Pivots thru out the interlocking linkages should be treated witha light oil (SAE #10) which includes rust inhibitors. The lubricantrecommended on page 26 may be applied.




Trip-Free Interlock (Fig. 12a, 24 & 26) circuit breaker frame, the ‘trip-free actuator’ (T4.5/62.8.8) risesinto the operator mechanism enclosure. This movement rotatesthe 'trip-free interlock levers’ (62.8.6 & 7) which in turn elevatethe ‘trip-free push rod and can assembly (62.8.5). Cam T en-counters the trip-free coupling lever (62.8.3) and after typically(0.3 to 0.5 inch) 8 to 12mm fo motion forces the mechanism,through the trip latch lever (64.2), to the ‘trip-free’ state.

The trip-free interlock is the combination of a roller arm(T4.1) onthe circuit breaker and the tirp-free interlock rail assembly (56)mounted on the right side of the cubicle. This combination oper-ates to hold the circuit breaker ‘trip-free’ unless the roller armcan extend from the low rail into the ‘vee’ groove at the ‘connect’to ‘test/disconnect’ positions. The high rail functions to dischargethe stored energy springs when the circuit breaker is withdrawnfrom the'cubicle and proper procedures were not followed. When the roller arm is extended into a ‘vee’ groove the ‘trip-

free’ push rod and cam assembly is lowered and and the cir-cuit breaker can be closed.When the roller arm is moved onto the low rail and closer the

42456

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mi Ai-4J 7&TIi

A V©i44I i&View of Right

Side of Cubicle © 25

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1A

(A

nf\r~n1. Screw racking mechanismassemblyRacking Latch

29. Racking InterlockPlateRacking key interlock

26. Trip-Free key interlock42. Shield43. Hex Head Drive nut44. Padlock hole.56. Trip-Free Interlocking Assembly

TI4.

25. i . ©-© U© %:© W-1L T

! : L JU-—56

J.Coni Test/DisconnectT4.1

hBreaker HeldTrip Free-

26Breaker Held—Trip Free—

Spring Discharge(Dump)Position—

VEE* GrooveTi mii k56 i F r-©SQ--" —>

LOW RAIL...c-' -̂ l HIGH RAILT4.1KVI/

% Front of CeltJ BreakerI j Spring DischargeTest Disconnect (Dump) Position

Position

(Connect PositionTop View

Section A-A

Figure 26. Trip-Free Interlock Assembly (Superimposed over screw racking mechanism)




Figure 24b. Drawout Truck Sub-assembly Showing Major Cubicle Interface items (Bolt Truck Type)




InterlocksDescriptionThe Siemens 3AF vacuum circuit breaker is comprised mainlyof the interrupter/operator sub-assembly fitted to a drawout trucksub-assembly. This interrupter/operator sub-assembly is an in-tegral arrangement of operating mechanism, dieletric system,vacuum interrupters, and means of connecting the primary cir-cuit. The drawout truck sub-assembly supports the inter-rupter/operator sub-assembly,providing mobility and fully coor-dinated application in Siemens type H2 switchgear.

A WARNINGInoperative or by-passed interlocks cancause death, serious personal injury and pro-perty damage.Mechanical and electical interlocks are pro-vided as integral components of this equip-ment to ensure safe use. Interlocks must bein operation at all times.Read this instruction manual. Know andunderstand correct interlock function.Check interlock function prior to insertingbreaker into switchgear cubicle.

Successful coordinated application of the fully assembled 3AFvacuum breaker is achieved thru precise fixtured alignment andimportant functional interlocking.

AlignmentElements of the vehicle structure, which are assembled underfixture control and then are secured, include the following (noadjustments are required):

• Cam roller guide wheels on truck assembly.• The primary circuit conductors are fixtured to appropriate

elevation, phase spacing and alignment to the racking blockand guide wheels.

• Secondary disconnects are fixtured and secured in place.• Shutter cam which raises and lowers protective primary

bushing barriers, is fixtured.• Breaker grounding bar is aligned and securely bolted in

place.• “TOC” switch actuator is located and secured.Thus, all those features which must align with elements of theswitchgear “drawout” enclosure, are precisely set and, firmlysecured while the complete breaker is located in a rigid fixture.

The H2 switchgear is designed for open of closed door screwracking of type 3AF vacuum circuit breakers between the ‘con-nect’ and ‘test/disconnect’ positions, only when the circuitbreaker is open. It is also designed to ensure that the closingsprings are discharged upon insertion of ‘withdrawal’ of the cir-cuit breaker from its cubicle if the proper procedures were no,followed. A system with racking and the trip-free movement in-terlocks is employed to perform these functions.

The circuit breaker primary circuit is closed by means of thevacuum interrupter contacts. The circuit breaker primary circuitis open (released) by means of the electrical or mechanicalreleases. These conditions are caused by the rotation of the cir-cuit breaker shaft (63).




POSITION OF TORQUE VVRENCH TO AVOID UNDUE STRESSINGOF MOVING TERMINAL 36.1

Figure 23. Illustration Showing Required Technique For Fastening Terminal Clamp Hardware

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 o*tube, and fasten securely.On some breaker a one pietring is used, and this is simply fastened in place.

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.

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




Vacuum Tube ReplacementReplacement 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.

1.6 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

It is recommended that one interrupter be removed and 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 5, 6, 22& 23.1. 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 thefactory 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 Figure23 and employ technique illustrated to fasten terminal

1.2 Loosen the lateral bo!t(s) on terminal clamp. 29.2. Referto Figure 23 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.




Interrupter Vacuum Check—Mechanical(Refer to Figures 21a. 21b, & 21c)

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:

>•

m

14 .48.6 48.5 48. 16.4 (

48 Insulated coupler48.6 Lever48.5 Pin

Cross ArmPort InsulatorLower pole support

141640

Figure 21a. Lower Pole Support With Insulated Coupler

Open and isolate the breaker and detach the insulated coupler,48, from lever, 48.6, Fig. 21a.

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. 21b.

Figure 20. 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°/o of expectedlife under full high fault current interruptions. The type 5-3AF-350and type 15-3AF-1000 circuit breakers should be checked atapproximately 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. 21c. 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 th^insulated coupler 48.




Lubricating Materials:Bearings and Sliding Surfaces

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

Grenier Industrial Park, Manchester, N.H. 03103

The main points to be lubricated with grease (bearings andsliding surfaces) are indicated in Fig. 18. All the points notmarked (bearings, articulated joints and auxiliary switch) shouldbe treated with light machine oil with rust inhibitor.

To 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 AshlandOil 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 18. Operator Lubrication Points




General Inspection Check List1. Check vacuum, procedures follows.2. Check contact erosion, procedure follows.3. Clean circuit breaker, especially post insulators and in-

sulating couplers.4. Lubricate all bearings and sliding surfaces, procedure and

materials follow.5. Check all terminal screws.6. Check all screw connections and locking devices on

mechanism parts.7. Check all control cables and connections.8. 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.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.

Hand Tools RecommendedThe 3AF breakers employ both English adn 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 toot 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"Metric

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.

• Sockets and Open-end Wrenches:7mm, 8mm, 9mm, 10mm, 11mm, 13mm, 17mm,19mm, 24mm

• Hex Key:THE USE OF UNAUTHORIZED PARTSIN 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 WARNING • 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.




i

— — — --SYMBOL LIST—*•- SPR1N® CHAR6INB MOTOR52SRC- SPRING RELEASE COIL ( CLOSE )52Y- CLOSINB RELAY ( AMTI-RUMP )S2T- SHUNT TRIP COILL$- SPAIN® CHARSED SWITCH32o- AUX SV - OPEN WHEN BAR IS OPEN52b- AUX SV - CLOSED VHEN BAR 1$ OPEN

REO JK0ICAT1N6 LI6HT ( CLOSE )a , 6- BREEN 1NOICATIN® LI6HT ( TRIP)I W- WHITE 1NOICATIN® LIGHT ( SPRINGS CHAR6EDI1 fl /C- CONTROL SV1TCK ( CLOSE )•1/T- CONTROL SWITCH ( TRIP)

2-FU

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2-FU 1 1

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tcNOTE •SHOWN AS TYPICAL. FOR ACTUAL CONTROL

SCHEMATIC SEE CONTRACT ORAWINBS.DEVICES AND WIRES SHOWN DASHED AREEXTERNAL TO THE BREAKER.I

54 154ISDB3

112C: >XOA11 6X0C12

58137

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j(sDAI0 j[sDA5A A

SDB 1 SOBSA A

1 1A 1 2A9 AX0A12

C 52 413 - b

SV A62

74 ,81;fb

>82

57A i X0A 2> AUX ±: QX0A7 1SD«> X 0A 1

2 i ::LS2ISOAI 7341 ' r 4A.

<L 52b133 42“LS4 1 C i iXOB 1 1 QXODI 2 pXOBl 2t/i T22 21±±LS3 ~52Y

**T 13:1 4 11B 120 12BIX0C 7 X 0C2u 22

YSDB2 YS034 IX0B7o 52 YBLUE 23.31 52 SDB4> 21 52o52bto SDAt 132 24 53<s» MOTOR 55 5731 1 1 C52Y OX0D7"A»

«yv7B GREEN AI32 ' 'xoci i70

A 1 9D5 ZUSR4..

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T .54~ 52o

LS22 SDfl3 «YT2 1CC 40 42 64.53'X0O 14 S0B7 S0B9 S0B1 1i X0B2 34 > XOO11

11 D

YSDA 12

4A 52o14 13C 13A 1 4C“T,mr\ '? XOC 14 |V

f XOC13 X0A13Y SDA4SDA9 SDA 9 52 ,93AUX ^SV 194

1 0 1 1 1351 f,b« ^ o

1 1 4SDA2

.1 1XOD1 3 AX0B13 1X 0 0 1 4130 13B I140

YSDB12>63

YSOBS YSDB10L.* _ LVN—'59 61

J L. I1 2-e m—Secondary

Disconnect—SDB(Optional)

Standard:Fuses in Close CrtSlugs In Trip Ckt (Fuses Optional)

18-607-583-41!3AF

Figure 15. 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 toa 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 16 and 17

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.

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

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. \

!



Interruptor/Operator - Description Page 20

Closing)C Contioi voltage applied

Anti-pumping feature {Device 52y)Care must be taken to see that a continuously applied closing command doesnot cause the breaker to reck»e after a has topped out on a fault, otherwiseit may sustain damage by the pumping effect

f ISpring ChargingMotor 88Energized

UndervoltageDevice 27*

Picks up

Closing SpringFully Charged ( Continuous closing commandi TI

LS21 andLS22 operTo de-energize springcharging motor 88

LS3 opens in serieswith anti-pump relay

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_ open

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

No action!Open52btnserieswithspring release solenoid(52SRC) blocks springrelease

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

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

Breakerdosed

Closing springnot charged T

No action!Belay $2y 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.

IContactsLS21 andLS22 close to energizemotor 88. LS3 dosesand LS4 opens tocancel closing springsignal

52acontactsinserieswith the trippingsolenoid dose 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.

L JThe dashed line shows theoperating sequence initiated byimpairing the closing command.

Rapid auto-reclosingThaciosmg spnng is recharged aulomaiicany asdescnbadabovt Therefore,when the breaker >s dosed both its springs are charged (the closing springcharges the tnppmg springduringc<os*gi As a-itsufl. thebreaker <scapableof anO-t-CO operating cycle (dead time t 03sl .

•Optional items Tripping

( )Trip command•Optional device

I TUndervoltage device.«27.is activatedbydosing NO contact,shorting the 27boil.The NO contact isconnected across 27 by52a contact thus theNO contact isonlyeffective with breakerdosed

*Undervoltage device.27.is activatedbyopening a NC contact inseries with 27 or byloss or reduction oftripping voltage

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

Opening solenoid.S2T.canonly be activatedwhen the seriesconnected 52a contactisclosed

I IUndervottage deviceOpening solenoid Secondary release *(27)52T

. . unlatches the trippingspring



I IlCircuit-breaker trips

Figure 13. Operator Sequential Operation Diagram




Legend Figures 12A-D 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

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

48 Insulated coupler53 Close pushbutton53.1 Closing solenoid, 52SRC53.2 Spring release latch54 Trip pushbutton54.1 Tripping Solenoid, 52T

64

63

0

Figure 12a. Operating Mechanism Section DiagramOperating Mechanism Open, Closing Springs Discharged(Starred items changed from 12c on ‘Trip* Operation) (Underlineditems changed from 12b on 'Closing Spring Discharge’ Operation)

Figure 12b. Operating Mechanism Section DiagramOperating Mechanism Open, Closing Springs Charged(Starred Items Changed From 12d on ‘Trip’ Operation) (Underlineditems changed from 12a on ‘Closing Spring Charge’ Operation)

*4




Figure 9. Details of Closing Spring Charging Components—Closing Spring Dischargedat the other end of the charging shaft is securely locked by the action by trip command or by means of the racking interlocks,latching pawl. When the closing spring is being charged, camdisc,(62.3), follows idly,i.e. it is brought into position for closing. The trip free coupling rod (62.8) forms a link between the drive

lever (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. 8, 9, 10, and 12)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).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

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 commandbeing given, the tripping solenoid52T,(54.1)unlatches the tripping spring (64).

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.




/

Figure 5. Section Through A Vacuum Breaker Pole31 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

' AX

32CHr IJ31

33 33.5

u 36 i

HS34m. 35SIiw36.1

36.2TEUTypical for

other ratings Typical for 5-3AF-250b.a

Figure 6. Section Through A Typical Vacuum Interrupter Figure 7. Section Through the Typical Vacuum Breakers




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 close-open indicator (58) closing spring charge indicator55, and the operation counter (59) are fitted on the front of themechanism housing. (Fig. 8)

Teh control connector (68.7) for the control and signalling cablesis a 64 contact plug or 24 point terminal block applied internal-ly to the drawout unit. (Fig 8)

Legend Figure 4

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

Figure 4a. Typical Interrupter/Operator Subassembly For5-3AF-250

Figure 4c. Typical Interrupter/Operator Subassembly For OtherRatings

Figure 4b. Typical Interrupter/Operator Subassembly For15-3AF-500, 1200A



Technical Data Page 10

i

General Performance DataTable 3. Operating Times - Typical Values Table 5. Typical Spring Charging Motor CharacteristicsCharacteristic Cycles 60 Hz Control Voltages

ANSI C37.06 Tbl. 10CurrentAmps

Charge TimeSeconds

msClosing TimeOpening TimeArcing Time at 60HzInterrupting Time

4.5 7548 VDC

125 VDC250 VDC120 VAC 60Hz240 VAC 60Hz

8 102.0 336 81 153 85036 83 8

Table 4. Typical Closing and Tripping Solenoid CharateristicsControl VoltagesANSI C37.06 Tbl. 10 Ohms

Close Coil Trip CoilAmps Ohms Amps Table 6. Auxiliary Switch Ratings

48 VDC125 VDC250 VDC120 VAC 60Hz240 VAC 60 Hz

23 2.1 2.4 20.0 Characteristic Rating1.0121 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

750 VA

‘



Technical Data Page 8

Rating Plate ContentClose (Solenoid)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.

TypeRequired range of control voltage appliedto 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.

VoltRange

AmpsNominal

Amps

Trip (Solenoid)Required range of control voltage appliedto 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.

VoltRated MaxVolts kV

Range

AmpsNominal

Volt RangeFactor (K)

Manual

LBSBIL kV

Serial No.

DateMfg.

Rated ShortCircuit kA

Close & Latch kA SIEMENS Raleigh, NC

A.C. High Voltage Circuit BreakerInter Time Cyc.

AMPS _VOLTAGE RANGE

_FACTOR KCLOSE &LATCH kA

TYPERATED MAXVOLTS kVRATED SHORTCIRCUIT kA

BILkV

INTERTIME CYCHz

WIRINGDIAGRAMHz

AMPSNOMINALAMPSNOMINALAMPSNOMINAL

VOLTSRANGEVOLTSRANGEVOLTSRANGE

Wiring Diagram MOTOR

CLOSE

Motor (Spring Charging) TRIPRange of control voltages required toserve the motor which stores energy in theclosing springs.

Volt LBS.MANUALRange DATEMPG.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



General Page 6

Installation CheckoutThe following agenda provides a convenient check list of activ-ities to be performed while withdrawing and preparing the cir-cuit breaker for use prior to reinsertion into the cubicle.

If the breaker is shipped separately from the switchgearcarefully remove the packaging using proper tools. Vacuumbreakers are normally supplied with their primary contactsopen and stored energy springs discharged. Press trip (54),close (53), and again trip push buttons to confirm this istrue. See Fig 3 Front Elevation. Breaker may now be careful-ly moved onto the transfer truck (or lift device).Refer to "Receiving” section for lifting alternatives.Carefully note and check rating plate (51) per Figure 2 toensure maximum voltage, continuous current,- interruptionrating, and control voltages are compatible with the systemand the cubicle into which the breaker is to be inserted.

1B.

The agenda may also be used for circuit breakers shippedseparately from the cubicles.

A DANGERh 2.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.

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

Using procedures described in the maintenance sectionof this manual, carry out a vacuum check.Complete a manual spring charge, close and trip operation.

Reinstall any barriers removed during inspection.Check primary contact assemblies. Fingers should be ful-ly engaged, spring loaded and arranged with symmetryabout the primary stud.De-energize cubicle control power,and install plug jumperbetween cubicle secondary disconnects and those of thebreaker. Upon re-energizing control power, closing springsshould automatically charge. Then close and trip the cir-cuit breaker with the local control switch.

3.

Refer to cubicle Instruction Book SG-3148 for important addi-tional information about the cubicle. 4.1A. If breaker is shipped in the switchgear withdraw the circuit

breaker from its cubicle as follows:

a) Confirm control power is de-energized by openingdisconnect device.

b) Confirm the vacuum circuit breakers primary contactsare open and the stored energy closing springs aredischarged, by pressing the trip (54) (red), then theclose (53) (black) and then the trip pushbuttons. SeeFig.3 Typical Operator Housing.

c) Operate screw racking mechanism to withdraw circuitbreakers from "connected” to "test/disconnect”position.

d) Push the two thumb levers on the latch disconnects(T3) while pulling forward on the handles T1.4.1 onbreaker front panel.This releases the breaker from theracking mechanism and moves it forward to thewithdrawal position.

e) Position accessory transfer truck (or lift truck) in frontof breaker cell with transfer truck’s guide pins insertedinto round alignment hole on each side of breaker celland then turn handies on transfer truck to lock it to thecubicle. The guide pin insertion releases the breakerwithdrawal interlock.

5.

6.

7.

8.

Note that with the breaker closed, the racking interlockblocking arm(T5 Fig. 24) on the right side of the truck hous-ing is raised. This interfaces with the cubicle and preventsthe movement of a closed circuit breaker.

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

11. De-energize control power and remove plug jumper. Presstrip (red), then close (black) and then trip pushbuttons toconfirm breaker is open and springs discharged.

12. Coat movable primary and secondary disconnects with alight film of Siemens contact lubricant, 15-171-370-002.

13. Observe location of secondary disconnect handle in cubi-cle (lower right side of breaker cell). Slide toward front ofcell and back. Note spring detent in toward position.

9.

f) Pull the circuit breaker forward onto the transfer truck.Rotate the transfer truck handles into position to releaseit from the cubicle and lock the breaker on the transfertruck.



General Page 4

Introduction ReceivingType 3AF vacuum circuit breakers are normally shipped fromthe factory completely assembled, inspected, tested andmounted in their respective switchgear cubicles. Immediatelyupon receipt of the switchgear and circuit breakers, check eachitem with the shipping manifest and make an examination forevidence of any damage that may have occurred duringshipment.

The 3AF 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 circuitbreakers. Performance requirements of these standards aremetor exceeded by these designs.

Specific Standards which apply include:

C37.04 IEEE Standard Rating StructureC37.06 Preferred Rating and Related Required

CapabilitiesC37.09 IEEE Standard Test ProceduresC37.010 IEEE Standard Application Guide

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.The successful performance and application of these vacuum

circuit breakers depends as much on proper installation andmaintenance as it does on good designandcareful manufacture.

NOTEThe 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.

Damage 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.

In some cases, Type 3AF vacuum circuit breakers are shippedseparate from their cubicles. In those cases, check and examineupon receipt and report any problems as indicated above.Carefully remove the packaging using the correct tools. The cir-cuit breakers may be carefully lifted using the lift holes on theupper rear side of the operator housing. See table 1 for weights.Care should be taken not to damage the insulators or circuitbreaker during and lifting or moving operations.

By carefully following these instructions, difficulties should beavoided. Flowever, 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.

NOTECircuit breakers with the letter A suffix indicates abolted truck assembly.



General Page 2

lb.15-3AF-250

1200A

1b.25-3AF-250A

1200A

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



Contents 03

Table of IllustrationsFigure 1a.Figure 1b.Figure 1c.Figure 2.Figure 3.Figure 4.Rgure 5.Figure 6.Rgure 7.Figure 8.Figure 9.Figure 10.Rgure 11.Figure 12.Figure 13.Rgure 14.Rgure 15.Rgure 16.Rgure 17a.Rgure 17b.Figure 17c.Rgure 18.Figure 19.Figure 20.Figure 21a.Figure 21b.Figure 21c.Rgure 22.Rgure 23.Figure 24a.Figure 24b.Rgure 25.Figure 26.Rgure 27.

Type 3AF Vacuum Circuit Breaker Front View :Type 3AF Vacuum Circuit Breaker Rear ViewType 15-3AF-500 Circuit Breaker in Test/Disconnect PositionRating PlateTypical Operator HousingTypical Innterrupter/Operator Sub-assemblySection Through a Vacuum 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 Discharged. . .Operating Mechanism Open Position - Closing Springs ChargedBreaker Shaft in Open Position - Closing Springs DischargedOperating Mechanism Section Diagrams: a, b, c, dOperator Sequential Operation DiagramFront View of Mechanism Enclosure Arranged for Manual OperationTypical Elementary DiagramConstruction of Shunt ReleaseLatch Detail Shunt ReleaseLatch Detail Undervoltage ReleaseUndervoltage Blocking FeatureOperator Lubrication PointsTypical Primary Interrupter Contact Life CurvesContact Erosion CheckLower Pole Support with Insulated CouplerPrimary Contact Closed - Free PositionPrimary Contact Forced Open by Manual PressureVacuum Tube Replacement IllustrationIllustration Showing Required Technique for Fastening Terminal Clamp HardwareDrawout Truck Sub-assemblyDrawout Truck Sub-assembly (Bolt Truck Type)Closed Breaker Racking Interlock Plate AssemblyTrip-Free Interlock AssemblySecondary Disconnect Wiring

1238

111214141415161717182021222323232326272828292931323536373839

Table 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

99

1010101025

Copyright 1987 - Siemens Energy & Automation



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