Instruction Manual 15kV KVAN-1125M 1200/2000A Maxi-Vac Medium-Voltage Vacuum Circuit Breaker

Transcription

1 Instruction Manual 15kV KVAN-1125M 1200/2000A Maxi-Vac Medium-Voltage Vacuum Circuit Breaker Circuit Breaker Sales, Inc Columbine Drive Gainesville, TX (940) Revision 2 March 2012

2 FIGURE 1 - CBS KVAN-1125M, 1200A KVAN-1125M 2 Rev. 2

3 CONTENTS 1.0 INTRODUCTION SAFETY RECEIVING, HANDLING, AND STORAGE RECEIVING AND HANDLING STORAGE DESCRIPTION AND OPERATION INTRODUCTION DESCRIPTION (Figure 4) MOVABLE FRAME STORED ENERGY OPERATING MECHANISM (Figure 6) OPERATION CHARGING OPERATION (Figure 10) CLOSING OPERATION (Figure 11) OPEN (TRIPPING OPERATION) (Figure 12) TRIP-FREE OPERATION RAPID AUTO-RECLOSE OPERATION CONTROLS AND INDICATIONS PREVENTATIVE MAINTENANCE AND ADJUSTMENTS GENERAL RECOMMENDED HAND TOOLS PREVENTATIVE MAINTENANCE RECOMMENDED ANNUAL INSPECTIONS PRIMARY POWER PATH CHECKS STORED ENERGY OPERATING MECHANISM CHECKS HIGH-POTENTIAL TESTS KVAN-1125M 3 Rev. 2

4 FIGURES Figure 1 - CBS KVAN-1125M, 1200A... 2 Figure 2 - CBS KVAN-1125M CIRCUIT BREAKER... 5 Figure 3 - CIRCUIT BREAKER LIFT POINTS... 7 Figure 4 - CIRCUIT BREAKER FRAME AND COMPONENTS... 8 Figure 5 - CIRCUIT BREAKER RATINGS NAMEPLATE... 9 Figure 6 - STORED ENERGY OPERATING MECHANISM Figure 7 - DISCONNECT ASSEMBLY Figure 8 - VACUUM INTERRUPTER, DETAIL Figure 9 - WIRING DIAGRAM Figure 10 - OPERATING MECHANISM, CIRCUIT BREAKER OPEN, CHARGING OPERATION Figure 11 - OPERATING MECHANISM, CIRCUIT BREAKER OPEN AND CHARGED - CLOSING OPERATION Figure 12 - OPERATING MECHANISM, CIRCUIT BREAKER OPEN AND CHARGED - OPENING OPERATION Figure 13 - CIRCUIT BREAKER CONTROLS Figure 14 - VACUUM INTERRUPTER EROSION MARK... Error! Bookmark not defined. Figure 15 - CONTACT WIPE GAP MEASUREMENT... Error! Bookmark not defined. Figure 16 - OPERATING MECHANISM COMPONENTS AND LUBRICATION POINTS Circuit Breaker Sales circuit breakers are tested and certified to ensure they are free of partial discharge. Circuit Breaker Sales recommends CBS ArcSafe remote racking solutions. KVAN-1125M 4 Rev. 2

5 FIGURE 2 - CBS KVAN-1125M CIRCUIT BREAKER 1.0 INTRODUCTION This manual covers the description; installation, operation, and maintenance of Circuit Breaker Sales (CBS ) Maxi-Vac type KVAN-1125 medium voltage vacuum circuit breakers. Personnel responsible for the operation of this equipment should be familiar with the procedures for the CBS type KVAN. 2.0 SAFETY Each user is responsible for maintaining a safety program to ensure the protection of personnel and equipment from the hazards associated with electrical equipment. The following basic industrial safety requirements apply to all major electrical equipment such as switchgear or switchboards. The following requirements are intended to augment the user s safety program but NOT supplant the user s responsibility for devising a complete safety program. CBS assumes no responsibility for practices that deviate from the following: ALL CONDUCTORS MUST BE ASSUMED TO BE ENERGIZED UNLESS THEIR POTENTIAL HAS BEEN MEASURED TO GROUND AND ADEQUATE CAPACITY GROUNDING ASSEMBLIES HAVE BEEN APPLIED TO PREVENT ENERGIZING. Many accidents have been caused by unplanned energization from unforeseen back feeds, equipment malfunctions, and other sources. VACUUM CIRCUIT BREAKERS ARE NOT TO BE CONSIDERED AS AN ISOLATING MEANS FOR PROVIDING SAFETY TO PERSONNEL UNLESS FULLY WITHDRAWN TO THE TEST POSITION. In the CONNECTED position with the breaker open, small leakage current with high voltage can flow across the open contacts. Also, leakage current can flow across the vacuum bottle or interrupter assembly if dirt or high humidity provides a path for tracking. It is strongly recommended that all equipment be completely de-energized, verified to be dead, and then grounded with adequate capacity grounding assemblies prior to performing any maintenance or troubleshooting. The grounding cable assemblies must be able to withstand energizing fault levels such that protective equipment may clear the circuit safely. See Chapter 20 of ANSI/NFPA 70B, Electrical Equipment Maintenance, for further information. Specific hazards throughout this instruction manual are presented in red danger call-outs, such as the following example: RED boxes contain information that point out potential hazards to personnel and equipment. KVAN-1125M 5 Rev. 2

6 While personnel should pay particular attention to the hazards presented in red danger call-outs, it would be impossible to alert the operator to every potential hazard. It is the responsibility of knowledgeable operators to rely on safe work practices to protect them from the inherent risks associated with industrial electrical equipment. Important information throughout this instruction manual is emphasized with green attention call-outs, such as the following example. ATTENTION GREEN ATTENTION boxes contain useful information to which the reader will want to pay particular attention. Circuit Breaker Sales Maxi-Vac circuit breakers are equipped with high-energy/high-speed mechanisms. The design includes several interlocks and safety features which help to ensure safe and proper operating sequences. To ensure the safety of personnel associated with the installation, operation, and maintenance of these circuit breakers, the following recommendations MUST be followed: Always ensure the circuit breaker displays OPEN/OFF prior to insertion to or removal from the connected position. Only qualified persons who are familiar with the installation and maintenance of medium-voltage circuit breakers should be permitted to work on these circuit breakers. Read this instruction manual before attempting any installation, operation, or maintenance of these breakers. DO NOT work on an energized circuit breaker DO NOT work on a circuit breaker unless all components are disconnected by means of a visual break and secure ground. DO NOT work on a circuit breaker while power is applied to the control power receptacle. DO NOT work on a closed circuit breaker; doing so may result in bodily injury. DO NOT work on a circuit breaker with a charged closing spring; doing so may result in bodily injury. DO NOT use a circuit breaker as the sole means of isolation of a high-voltage circuit. DO NOT install or remove circuit breakers without adequate personal protective equipment and/or a specifically designed remote racking device (contact CBS for remote racking solutions). 3.0 RECEIVING, HANDLING, AND STORAGE 3.1 RECEIVING AND HANDLING Every circuit breaker is carefully tested and inspected then packaged securely to ensure the breaker arrives safely. Immediately upon recipient, the circuit breaker should be examined to ascertain if any damage was sustained during transit. If damage or evidence of rough handling is present, or the Tip n Tell indicator is missing or disturbed, file a damage claim immediately with the transportation company and contact the Circuit Breaker Sales sales office. Remove all traces of packing, crating, and foreign material carefully. Exercise care while uncrating the circuit breaker so that no damage will occur from careless or rough handling or from exposure to moisture or dirt. Save the shipping material for storing the circuit breaker when not in use. Verify the order with the packing list to ensure that no components have been overlooked or misplaced, such as racking and charging tools, test reports, and instruction booklets. The circuit breaker is normally shipped in the CLOSED position with the springs DISCHARGED to KVAN-1125M 6 Rev. 2

7 prevent damage from occurring to the vacuum interrupter during shipment. Verify the indicator flags (Figure 13-5) on the front of the circuit breaker display OPEN and DISCHARGED prior to uncrating, moving, installing, or removing. When lifting the circuit breaker, use of lift rigging is recommended. Two lift locations, one per side, are provided on the right and left sides of the circuit breaker housing (Figure 3). When lifting, ensure a properly rated lifting apparatus is used, lift and lower the circuit breaker slowly, and avoid abrupt movements. completely covered and protected from rain, snow, dirt and all other contaminants. If the breaker is stored for any length of time, it should be inspected periodically to ensure that rust is not present and that the breaker is in good mechanical condition. Should the breaker be stored under unfavorable atmospheric conditions, it should be cleaned and dried out prior to being placed into service. DO NOT improperly lift the breaker via the primary disconnects. The circuit breaker, strapped to a pallet, can be moved with a properly rated forklift. The circuit breaker weight is 300 lbs., 350 lbs. crated). 3.2 STORAGE After inspection it is recommended that the circuit breaker be put into service in its permanent location immediately. If the circuit breaker cannot be placed into service ensure the following storage criteria are met: Store the breaker unpacked, OPEN, and DISCHARGED. FIGURE 3 - CIRCUIT BREAKER LIFT POINTS The breaker should be carefully protected against condensation, preferably by storing it in a warm, dry room of moderate temperature such as 5 37⁰C (41 98⁰F). An environment high in humidity may have an adverse effect on the circuit breaker insulation and should be avoided. The breaker should be stored in a clean location, free from corrosive gases or fumes; particular care should be taken to protect the equipment from moisture and cement/mineral dust, as this combination has a very corrosive effect on many breaker components. Cover the circuit breaker with a plastic sheet to protect from dust, dirt and small animal or insect infestation. Outdoor storage is not recommended. When no other option is available, the breaker must be KVAN-1125M 7 Rev. 2

8 FIGURE 4 - CIRCUIT BREAKER FRAME AND COMPONENTS 1. Faceplate 4. Insulating Phase Barriers 6. Movable Frame (Truck) 2. Operating Mechanism 5. Primary Disconnects 7. Fixed Wheels (x4) 3. Ratings Nameplate 4.0 DESCRIPTION AND OPERATION 4.1 INTRODUCTION This section provides basic descriptions of the circuit breaker components and its operation. A thorough understanding of the KVAN-1125M circuit breaker hardware must be reached prior to installation, operation, and maintenance of the equipment. The circuit breakers described in this manual are designed and tested to operate within their nameplate ratings. OPERATION OUTSIDE OF THE RATINGS MAY CAUSE EQUIPMENT TO FAIL, RESULTING IN PROPERTY DAMAGE, BODILY INJURY, AND/OR DEATH. 4.2 DESCRIPTION (Figure 4) The KVAN-1125 circuit breaker is comprised of a movable frame (truck) (6), on which is mounted the stored energy operating mechanism (2) and the disconnect assembly (4, 5), ATTENTION All descriptions of circuit breaker operations and component locations assume the operator/reader is viewing the circuit breaker from the front unless otherwise stated MOVABLE FRAME The movable frame is constructed of heavygauge steel and is the main support structure of the circuit breaker. The frame includes of the steel wheels (Figure 4-8), and the faceplate (Figure 4-1, 2). Steel Wheels Four non-pivoting steel wheels provide a means repositioning the circuit breaker in the switchgear and removing the breaker from the cubicle for circuit isolation and maintenance. Operating Mechanism Faceplate The circuit breaker mechanism faceplate protects the operator from both the control voltage and the high-energy moving parts of the operating mechanism. The circuit breaker ratings nameplate (Figure 5) is mounted to the operating mechanism faceplate. KVAN-1125M 8 Rev. 2

9 FIGURE 5 - CIRCUIT BREAKER RATINGS NAMEPLATE KVAN-1125M 9 Rev. 2

10 FIGURE 6 - STORED ENERGY OPERATING MECHANISM 1. Auxiliary Switch 5. Operations Counter 9. Closing Spring 2. Anti-Pump Relay 6. Trip (Open) Coil 10. Motor Cut-Off Switch (LS1) 3. Charging Motor 7. Close Coil 11. Closing Spring Charged Switch 4. Aux. Switch Operating Linkage (LS2) STORED ENERGY OPERATING MECHANISM (Figure 6) The stored energy operating mechanism is the main electrical and mechanical control assembly of the circuit breaker. The mechanism consists of the following components: the charging motor (3), the closing and tripping springs (10), the dashpot assemblies, the close (9) and trip solenoids (6), the anti-pump relay (2), the auxiliary (1) and limit switches (11, 12). The stored energy operating mechanism provides for the opening and closing of the circuit breaker both mechanically and electrically. All elements of the stored energy operating mechanism are contained in the circuit breaker mechanism housing. A detailed explanation of the stored energy operating mechanism is described in Section 4.3. Charging Motor (3) The charging motor drives the operating mechanism which converts the rotational energy of the motor to compress (charge) the closing spring whenever control power is available and the spring is discharged. The operating mechanism can also be charged manually via the charging screw and handle. Closing and Tripping Springs (10) The closing and tripping springs are compressed to store energy for future breaker operation. The closing spring is located on the right side of the housing. The closing spring is charged and discharged via the rotation of the crank arm mounted on the rotating main KVAN-1125M 10 Rev. 2

11 camshaft. The fixed end of the closing spring is attached to a support arm which in turn is bolted to the structure of the circuit breaker. The tripping spring is located on the bottom rear side of the housing. The tripping spring is connected to the jackshaft. When the closing spring is discharged, closing the circuit breaker, rotation of the jackshaft causes the tripping spring rod to extend and charge the tripping spring. Consequently, the tripping spring is automatically charged when the breaker is closed by the closing spring. Dashpot Assemblies The circuit breakers are equipped with a dashpot assembly on phases A and C, located on the rear of the housing. The dashpots are pistons, vented to oil. The dashpot piston absorbs the opening energy of the circuit breaker, limiting the force on the operating mechanism during an opening operation. Close Solenoid (9) Mechanically or electrically activating the armature of the close solenoid triggers the release of the energy stored in the closing spring, which in turn forces the three insulating push-rods to reposition the movable vacuum interrupter contacts vertically, closing the circuit breaker. Limit Switches (11, 12) In addition to the main auxiliary switch, the circuit breaker contains two limit micro-switches for use in the circuit breaker control circuitry. The motor cutoff switch (LS1) (11) is used to sense the position of the operating mechanism. The switch energizes the charging motor when the closing spring is discharged and opens once the closing spring is fully charged. The closing spring charged switch (LS2) (12) operates in conjunction with the motor cutoff switch (LS1). The closing spring charged switch allows the closing solenoid to be energized only when the closing springs are fully charged. The switch is also used in the anti-pump circuit DISCONNECT ASSEMBLY The disconnect assembly is the primary current path of the circuit breaker. The disconnect assembly is comprised of the primary (Figure 4-5) disconnects, the vacuum interrupters (Figure 8), insulating pushrods, and the phase barriers (Figure 4-4). Trip Solenoid (6) Mechanically or electrically activating the armature of the trip solenoid allows the energy stored in the tripping spring to rotate the jackshaft. Rotation of the jackshaft pulls the pushrods attached to the movable contacts within the vacuum interrupters downward, opening the circuit breaker. Anti-pump Relay (2) The anti-pump relay electrically isolates signals to the close solenoid so that a single close signal cannot cause multiple closings of the circuit breaker. The circuit breaker must be tripped, the closing springs recharged, and the close signal removed (interrupted) to reset the anti-pump relay, allowing the close solenoid to be reenergized and thus the breaker to be closed. Auxiliary Switch (1) The breaker-mounted auxiliary switch provides auxiliary contacts for the control circuitry of the circuit breaker and contacts for use in relaying and external logic circuits. The auxiliary switch is actuated by linkage connected to the jackshaft. The auxiliary switch contains both normally open (A) and normally closed (B) contacts. To clarify, when the circuit breaker is closed, A contacts are closed, while B contacts are open. FIGURE 7 - DISCONNECT ASSEMBLY Vacuum Interrupters (Figure 8) Each circuit breaker contains three vacuum interrupters (commonly known as vacuum bottles), one bottle per phase. The vacuum interrupters are essentially a KVAN-1125M 11 Rev. 2

12 movable and stationary contact enclosed within a vacuum chamber. The upper, stationary terminal of the vacuum interrupter is connected to the upper disconnect stud of the stored energy operating mechanism which in turn is connected through a copper bus-bar to the upper primary disconnect. The interrupter lower, movable terminal passes through the ring contactor of the lower disconnect stud and connects to the driving mechanism of the circuit breaker via an insulated push-rod; the lower disconnect stud is connected to the lower primary disconnect of the circuit breaker via a copper busbar. A metal bellows assembly provides a secure seal around the movable contact, preventing a loss of vacuum while permitting vertical motion of the movable contact. Insulated Push-rods There are three insulated push-rods. Each push-rod connects the movable terminal of one of the vacuum interrupters to the jackshaft of the stored energy operating mechanism. The push-rods transfer the work from the stored energy operating mechanism to the movable terminals while insulating the high voltage potential present on the primary disconnect assembly from the circuit breaker frame and operating mechanism. Primary Disconnects (Figure 4-5, Figure 7) The circuit breaker has three sets of primary disconnects, one set per phase. The three upper primaries are connected to the stationary terminals of the vacuum interrupters, the three lower primaries attach to the movable terminals. When the circuit breaker is in the CONNECTED position, the female primary disconnects connect with male, stationary disconnect studs in the cubicle. Phase Barriers (Figure 4-4) Each vacuum interrupter assembly is insulated via its vacuum interrupter phase barrier. FIGURE 8 - VACUUM INTERRUPTER, DETAIL KVAN-1125M 12 Rev. 2

13 FIGURE 9 - WIRING DIAGRAM KVAN-1125M 13 Rev. 2

14 FIGURE 10 - OPERATING MECHANISM, CIRCUIT BREAKER OPEN, CHARGING OPERATION 4.3 OPERATION This section introduces and explains the modes of CBS Maxi-Vac Type KVAN-1125 circuit breaker operation. The status conditions of the circuit breaker are the charging, closing, opening (tripping), trip-free, and rapid auto-reclosing modes of operation. Also included in this section is an explanation of the circuit breaker interlocks, spring dump and MOC actuator mechanisms CHARGING OPERATION (Figure 10) In charging operation it is assumed that the breaker is OPEN and inserted in the compartment in the TEST or CONNECTED position. When the secondary disconnect is connected, the motor disconnect switch is in the ON position and control power is applied to auxiliary disconnect pins 2 and 5, the charging motor will energize. Rotation of the charging motor rotates the bevel gear and offset shaft which translates the rotational work of the motor to the vertical, reciprocating motion of the driving pawl. As the driving pawl is lowered and raised, the lower end of the pawl engages the ratchet wheel on the operating main camshaft (6). ATTENTION All explanations assume that the reader/operator has read and understands the descriptions of the circuit breaker components in Section 4.2 and the breaker control schematic presented in Figure 11. Through ratcheting, the reciprocation of the driving pawl is converted to rotation of the main camshaft. As the camshaft is rotated the closing spring crank arm rotates and charges the closing spring. When the closing spring is charged, two cams on the mechanism camshaft open the motor cutoff limit switch (LS2), and close the closing spring charged switch (LS1). Opening the motor cutoff switch deenergizes the charging motor. The closing spring is now charged. The close hook (12-9) latches the energy stored in the closing spring from continuing to rotate the camshaft and close the breaker. The circuit breaker can also be charged manually. The circuit breaker is manually charged by inserting the charging handle into the charging screw. The charging screw is accessible through an opening in the housing faceplate. Clockwise hand rotation of the charging handle rotates the charging pinion, which charges the closing springs as previously described. ATTENTION The circuit breaker cannot be over-charged if the charging screw is excessively operated. KVAN-1125M 14 Rev. 2

15 FIGURE 11 - OPERATING MECHANISM, CIRCUIT BREAKER OPEN AND CHARGED - CLOSING OPERATION CLOSING OPERATION (Figure 11) In an effort to simplify the explanation of circuit breaker operation, the initial conditions for the closing operation assume that the charging operation has occurred; the breaker is inserted in the TEST or CONNECTED position and the breaker status is OPEN and CHARGED. The charging operation ensures that the closing spring charged switch (LS2) is closed, completing a path for the closing signal For the purpose of explaining the circuit breaker closing operation it is assumed that the anti-pump circuit is satisfied. A closing signal applied to auxiliary disconnects pins 7 or 6 and 4 energizes the closing coil (52C) which forces the solenoid armature against the close hook (Figure 10-9); pushing the green close pushbutton (I) on the circuit breaker faceplate accomplishes the same task to manually close the breaker. Mechanically or electrically activating the armature of the close solenoid releases the close hook, discharging the energy stored in the closing spring which rotates the operating mechanism main camshaft. Levers on the jackshaft rotate upward, forcing the three insulating push-rods (Fig ) to reposition the movable vacuum interrupter contacts vertically (Figure 10-8), closing the circuit breaker. The trip hook (Figure 10-5) latches the trip hook roller (Figure 10-4), holding the mechanism in the closed position. During the closing operation the closing springs are discharged; thus, a charging operation will occur (Figure 10). Anti-pump circuit The anti-pump circuit electrically isolates signals to the close solenoid so that a single close signal cannot cause multiple closings of the circuit breaker. The circuit breaker must be tripped, the closing springs recharged, and the close signal removed (interrupted) to reset the anti-pump relay, allowing the close solenoid to be reenergized and thus the breaker to be closed. As discussed in the previous section, when the circuit breaker closes, the A contacts of the auxiliary switch close while the B contacts open. When the circuit breaker closes, the normally closed, auxiliary contact (52B) opens, preventing the closing coil from being energized until the circuit breaker is tripped. The anti-pump relay (52Z) is energized by closing of the normally open (52A) contacts in the closing circuit. The anti-pump relay closes a maintaining contact, keeping the relay energized until the operator removes (interrupts) the closing signal to the breaker. The relay also opens a contact in series with the closing coil (52C), removing power to the closing coil (52C). The anti-pump circuit is reset by removing power from the closing circuit. KVAN-1125M 15 Rev. 2

16 FIGURE 12 - OPERATING MECHANISM, CIRCUIT BREAKER OPEN AND CHARGED - OPENING OPERATION OPEN (TRIPPING OPERATION) (Figure 12) In an effort to simplify the explanation of circuit breaker operation, the initial conditions for the opening operation assume that the closing operation has occurred; the breaker is inserted in the TEST or CONNECTED position, and the breaker status is CLOSED and CHARGED. The closing operation rotates the jackshaft Figure 10-11) which causes the tripping spring rod to extend and charge the tripping spring. Consequently, the tripping spring is automatically charged when the breaker is closed by the closing spring. Closing the circuit breaker closes the normally open auxiliary contact (52A) in series with the tripping coil. A tripping signal applied to auxiliary disconnect pins 3 or 10 and 9 energizes the tripping coil (52T), which activates the solenoid armature against the trip hook (Figure 10-5); pushing the red trip pushbutton (O) on the circuit breaker faceplate accomplishes the same task to manually trip the breaker. Mechanically or electrically activating the armature of the trip solenoid releases the trip hook roller (Figure 10-4). Releasing the trip hook roller allows the operating mechanism to rotate; discharging the energy stored in the tripping spring, and consequently rotating the operating mechanism jackshaft. Levers on the jackshaft rotate downward, forcing the three insulating push-rods to reposition the movable vacuum interrupter contacts vertically, opening the circuit breaker TRIP-FREE OPERATION The KVAN-1125 circuit breaker is mechanically and electrically trip-free ; this important function enables the breaker to be tripped prior to, during, or after a closing operation. Whenever the circuit breaker trip hook is released and held either manually or electrically: A circuit breaker will open. A circuit breaker in the process of closing will not complete the closing operation and will remain open. An open circuit breaker will not be able to be closed RAPID AUTO-RECLOSE OPERATION As explained in Section and 4.3.2, the closing springs are recharged by the charging motor when the circuit breaker is closed, thus the circuit breaker can be closed immediately following an opening operation. The operating mechanism is capable of the OPEN CLOSE OPEN duty cycle required for rapid auto-reclosing. The trip hook prevents the release of the closing springs if the trip hook roller is not in its reset position, ensuring the mechanism does not operate trip-free on an instantaneous re-closure. KVAN-1125M 16 Rev. 2

17 1. Operations Counter 2. Manual Charging Mechanism 3. Manual Close Button 4. Manual Open Button 5. On/Off Breaker Contact Status Indicator 6. Charged/Discharged Stored Energy Operating Mechanism Indicator 7. Nameplate 5.0 CONTROLS AND INDICATIONS The controls and indications are located on the front of the circuit breaker housing; see Figure 13. FIGURE 13 - CIRCUIT BREAKER CONTROLS KVAN-1125M 17 Rev. 2

18 6.0 PREVENTATIVE MAINTENANCE AND ADJUSTMENTS 6.1 GENERAL Periodic inspections and maintenance are essential to obtain safe and reliable operation of the circuit breaker. When the circuit breaker is operated infrequently (fewer than 20 times per week), and is located in a clean and dry indoor location, annual inspections are generally satisfactory. However, when the circuit breaker is operated more than 20 times per week, or when adverse environmental conditions exist, it is likely that more frequent inspections are required. The maintenance section of the operations manual is designed to provide general guidance for maintenance practices to supplement, not supplant, maintenance programs. It is the responsibility of technical personnel to adapt the following maintenance guidelines to the specific operating conditions that are present. Only qualified persons who are familiar with the installation and maintenance of medium-voltage circuit breakers should be permitted to work on these circuit breakers. Read this instruction manual before attempting any installation, operation, or maintenance of these breakers. DO NOT work on an energized circuit breaker. DO NOT work on a circuit breaker unless all components are disconnected by means of a visual break and secure ground. DO NOT work on a circuit breaker while power is applied to the control power receptacle. DO NOT work on a closed circuit breaker; doing so may result in bodily injury. DO NOT work on a circuit breaker with a charged closing spring; doing so may result in bodily injury. The circuit breaker housing protects the operator from both the control voltage and the high-energy moving parts of the operating mechanism; removing the circuit breaker housing will expose the operator to these hazards RECOMMENDED HAND TOOLS CBS Maxi-Vac KVAN-1125 circuit breakers utilize metric and standard fasteners. The following hand tools, materials and test equipment are those normally used in disassembly, re-assembly, and testing procedures: Torque Wrench, Nm (0-100 ft-lbs) Socket and Combination Wrenches 6, 8, 10, 12, 16 mm Screwdriver Set, Phillips and Standard Pliers Dry, lint-free cloths Mobil 28 Contact Grease (or equivalent) Nye RHEOLUBE 363 Grease (or equivalent) No. 1, No. 2, Isopropyl, or Isobutyl Alcohol Mobil 1 or SAE 10 Motor Oil with rust inhibitors HIGH-Potential Test Set 2500 and 500VDC Megger Micro-ohmmeter (Ductor) 6.2 PREVENTATIVE MAINTENANCE RECOMMENDED ANNUAL INSPECTIONS Periodic inspections occurring at annual, or more frequent, intervals should include all of the following tasks: Checks of the primary power path Checks of the vacuum interrupter Checks of the mechanism Checks of the control power High-potential test Inspection and cleaning KVAN-1125M 18 Rev. 2

19 As Found Tests Some users perform As Found insulation tests using a Megger or Doble testing to give an As Found value for future comparative indication of insulation change. This is especially desirable for new circuit breakers if they are to be stored for extended periods, and may absorb moisture or contaminants. Since wide variations can occur in insulation values because of atmospheric conditions, contamination, and test equipment, discrete values cannot be given. However, making and recording test values on new equipment and at regular intervals will give a comparative indication of insulation condition. Maintaining a permanent record of these values for each circuit breaker should be part of the Maintenance Program. *Always open and close breakers installed in energized switchgear by remote means PRIMARY POWER PATH CHECKS The primary power path consists of the three vacuum interrupters and the six primary disconnects. These components are checked for cleanliness and condition. The vacuum integrity of the vacuum interrupters is also verified. 1. Inspect the primary disconnect insulators for physical integrity and cleanliness, and verify they are free of marring or damage. 2. Check the fasteners of the primary power path for tightness. 3. Perform the vacuum integrity verification detailed in the high-potential test section STORED ENERGY OPERATING MECHANISM CHECKS The operating mechanism checks are divided into mechanical and electrical checks. Mechanical Checks The first series of checks determines if the mechanism operates smoothly without control power, is clean, and is adequately lubricated. A vacuum interrupter contact erosion measurement is also performed. The circuit breaker operating mechanism contains high-energy moving parts. Use caution when the circuit breaker is closed and the springs are charged. 1. Discharge the stored energy mechanism by pressing the trip button, the close button, and the trip button again in succession. 2. Remove the circuit breaker housing faceplate. 3. Inspect the circuit breaker mechanism for signs of excessive wear and general cleanliness; place special attention upon the closing spring cranks, closing camshaft, jackshaft and the various pushrods and linkages. 4. Clean the entire stored energy operating mechanism with a dry, lint-free cloth. 5. Under normal service conditions, the KVAN circuit breaker should be lubricated every 2,000 closing operations. See Figure 16 for lubrication points. 6. Lubricate all non-electrical moving or sliding surfaces with a light coat of machine oil containing a rust inhibitor: Bearing and sliding surfaces use Nye RHEOLUBE 363 grease or equivalent. Pivots and articulated joints use Mobil 1 or SAE 10 motor oil with rust inhibitors. Electrical Fastener Torque Requirements BOLT HEAD SIZE TORQUE (ft-lbs.) TORQUE (N-m) 5/ /2" / /4" ATTENTION Clean but DO NOT lubricate the dashpot assemblies. 7. Perform a fastener check. Inspect all fasteners for tightness. Both lock-nuts and retaining devices are used. Replace any fasteners that KVAN-1125M 19 Rev. 2

20 appear to have been frequently removed and replaced. 8. Visually inspect the dashpot assembly for leaks or signs of wear. 9. Manual Operation Check Check the vacuum circuit breaker operation manually. a. Manually charge the closing spring with the manual charging handle. b. Once fully charged, close the circuit breaker via the CLOSE pushbutton. c. Open the circuit breaker by pressing the OPEN pushbutton. d. Operate the circuit breaker several times successively. e. Verify the circuit breaker operates smoothly and free of defects. f. Close the circuit breaker to perform the contact erosion check. 10. Check contact wear of the vacuum interrupters. Replace the vacuum interrupters when the wipe gauge will not insert to the specified gap. 11. Perform the Spring Discharge Procedure. 12. Clean the barriers and primary insulators with a clean, lint-free cloth and No. 1 or No. 2 denatured alcohol or isopropyl or isobutyl alcohol. If the insulation material is exceptionally contaminated, clean with a mild soap with water and follow with alcohol. ATTENTION If As Found testing is desired, delay the cleaning of the insulation until testing is performed. 13. Replace all barriers, ensuring all fasteners are tight and in adequate condition. Electrical Checks The electrical controls of the KVAN-1125 circuit breaker should be tested annually after it is verified the circuit breaker is free of mechanical faults. The electrical control check verifies proper operation of the automatic spring charge, close, trip, and anti-pump circuits. Unless otherwise noted, all tests are performed without control power applied to the circuit breaker. 1. Check circuit breaker wiring and terminals. Physically check all wiring of the circuit breaker for evidence of abrasion, cuts, burning, or other physical damage. Ensure all terminals are securely attached to their respective devices. ATTENTION A temporary source of control power and test leads is required to verify the electrical circuits of the circuit breaker if a control power test plug is unavailable. 2. Energize the control power source, and verify the closing spring charged. 3. Electrically operate the circuit breaker several times to verify it is functioning properly. 4. To check the anti-pump circuits, with the circuit breaker open, apply and maintain power to the closing circuit; the breaker will close. With power applied to the closing circuit, power the trip circuit to open the circuit breaker. The circuit breaker should open and remain open. Interrupt the power applied to the closing circuit and the breaker will close. 5. The spring charge motor brushes require inspection every 7,000 operations. Use the circuit breaker operations counter to determine if brush inspection/replacement is necessary HIGH-POTENTIAL TESTS The next series of tests involve the use of highvoltage test equipment. The voltages for highpotential tests are: Equipment kv Rating 15kV Maximum Test Voltage 36kV DC HIGH-POTENTIAL tests employ HAZARDOUS VOLTAGES which will cause SEVERE PERSONAL INJURY AND/OR DEATH. Follow safe procedures, exclude unnecessary personnel and use safety barriers. Maintain a safe distance from the circuit breaker while test voltages are applied. KVAN-1125M 20 Rev. 2

21 Vacuum interrupters may emit X-RAY RADIATION which can cause BODILY INJURY. X-rays can be produced when a high voltage is placed across two circuit elements in a vacuum. Keep personnel more than six (6) DO NOT use DC HIGH-POTENTIAL test devices incorporating half-wave rectification; these devices produce HIGH PEAK VOLTAGES. High peak voltages will produce X-ray radiation; these devices also show erroneous readings of leakage current when testing vacuum circuit breakers. 1. Vacuum Interrupter Integrity Verification A high-potential test is used to verify the vacuum integrity of the circuit breaker. a. Observe safety precautions listed in the danger call-outs. b. Ensure the circuit breaker is OPEN. c. Ground each pole not under test. 2. Apply test voltage across each pole for one minute. 3. The vacuum integrity is verified if the pole sustains the test voltage for the duration it is applied. 4. As-found Insulation Tests Insulation tests verify the integrity of the breaker insulation system. Megger and/or Doble tests performed on the circuit breaker at the factory prior to installation provide a basis for future comparison to detect changes in the protection afforded by the insulation system. A permanent record of as-found tests enables the maintenance organization to determine when corrective actions are required by watching for sudden deterioration in insulation resistance or increases in contact resistance. a. Observe safety precautions listed in the red danger call-outs. b. Manually charge and close the circuit breaker using the procedures detailed in Section 1.2. c. Ground each pole not under test d. Apply a 2500VDC high-potential test voltage between a primary conductor of the pole and ground for one minute. e. If no disruptive discharge occurs over the duration of the applied voltage and/or insulation resistance levels are >1,000MΩ, the insulation system is satisfactory. f. After the test, ground each end and the center of each vacuum bottle to dissipate any static charge. Repeat the test pole-topole and across open poles. g. Disconnect the leads to the charging motor. h. Connect all points of the control power plug to a shorting wire(s). Connect the shorting wire(s) to the high-potential lead of a 500VDC Megger set and the breaker housing to ground. i. If no disruptive discharge occurs and/or insulation resistance levels are >50MΩ, the control power wiring insulation level is satisfactory. j. Remove the shorting wire(s) and re-attach the charging motor leads. k. Using a micro-ohmmeter (Ductor), perform contact resistance test of the primary contacts. Investigate any values which deviate from other poles and historical data by more than 50 percent of the lowest value. l. Make a permanent record of all tests performed for trending/analysis. KVAN-1125M 21 Rev. 2

22 FIGURE 14 - OPERATING MECHANISM COMPONENTS AND LUBRICATION POINTS KVAN-1125M 22 Rev. 2

23 KVAN 23 Rev. 9 Notes:

24 KVAN 24 Rev. 9

25