Live Tank Circuit Breaker

Transcription

1 Live Tank Circuit Breaker Auto-Puffer TM SF6 Circuit-breakers for outdoor installation Rated voltages kV Rated currents 4000A Rated breaking currents 50kA

2 Content LTB FAMILY Contents I. Introduction...1 II. Design Feature Auto-Puffer TM...2 III. LTB Design Features and Advantages...4 IV.Technical Data According to ANSI...12 V. Technical Data According to IEC...13 VI. Dimensions-LTB...14 VII. Shipping Data for LTB...16

3 LTB FAMILY Introduction Introduction Exceeding Customer Expectations -ABB Live Tank Circuit Breakers ABB has over a century of experience in developing, testing and manufacturing high voltage circuit breakers. Through the years, our circuit breakers have acquired a reputation for high reliability and long life in all climates and in all parts of the world. ABB s LTB circuit breaker family, with rated voltage kv and breaking current up to 50 ka, satisfies the highest demands. It is based on latest developments in dielectric dimensioning and arc physics research. ABB produced the world s first SF 6 circuit breakers with arc-assisted interrupters in the mid-1980 s - Auto-Puffer TM.The energy required for interrupting short circuit currents is partly taken from the arc itself,significantly reducing the energy required from the operating mechanism. Lower operating energy inherently reduces mechanical stresses, on the circuit breaker itself as well as on the foundation, and increases circuit breaker reliability. For many years, ABB has used operating mechanisms with energy mechanically stored in springs. This solution offers considerable advantages in that the energy in the tensioned springs is always available. The design of the LTB is a well-proven technology (over 20,000 units are in service). = Brief Performance Data: Installation Design Outdoor/Indoor SF6 Auto-Puffer TM interrupter spring operating mechanisms Insulation SF 6 Rated kv Rated Current 4,000 A Breaking Current 50 ka Short Time Current 50 ka/3 s Insulators Composite or Porcelain Creepage Distance 25 mm/kv (longer on request) Service Condition Ambient Temperature - 30 to+40 Operation in temperature down to -55 or up to+70 Design Altitude 1,000 m.a.s.l. Higher altitude on reques Type of Operation Single- or Three- pole 1

4 Auto-Puffer TM LTB FAMILY Design Feature Auto-Puffer TM Design Feature Auto-Puffer TM Interrupters Contact Parting Closed Main Arcing ValveOperation Arc Extinction Open 1. Upper current carrier 2. Stationary arcing contact 3. Moving arcing contact 4. Auto-Puffer TM volume 5. Puffer volume 6. Refill valve 7. Stationary piston 8. Nozzle 9. Stationary main contact 10. Moving main contact 11. Auto-puffer? valve 12. Puffer cylinder 13. Over-pressure relief 14. Lower current carrier When interrupting high currents (e.g. rated shortcircuit current), Auto-Puffer TM interrupters show the advantage they were designed to provide. On opening, the operation of an Auto-Puffer TM interrupter at high current begins the same way as a puffer interrupter. It is not until after arcing begins that a difference in the operation principle is seen between the high and low current interrupting cases. When the arcing contacts part, an arc is drawn between the moving and stationary arcing contacts. As the arc flows, it to some degree blocks the flow of SF 6 gas through the nozzle. The arc drawn is extremely hot and radiates a lot of heat and begins to heat the SF 6 gas in the interrupting gas volume. Thus, the pressure inside the Auto-Puffer TM and puffer volumes increases due to the rise in temperature as well as due to the com-pression of gas between the puffer cylinder and stationary piston. Gas pressure inside the Auto-Puffer TM volume continues to increase until it is high enough to force the Auto-Puffer TM valve to the closed position. All SF 6 gas required for interruption is now trapped in the fixed Auto-Puffer TM volume and any further increase in gas pressure in that volume is due solely to heating from the arc. At about the same time, the gas pressure in the puffer volume reaches a level sufficient to push the overpressure valve open. Since the gas in the puffer volume escapes through the overpressure valve, Design Features Auto- Puffer TM Interrupters there is no need for a high operating energy to overcome the compression of 2

5 LTB FAMILY Auto-Puffer TM Design Feature Auto-Puffer TM Interrupters SF 6 gas while at the same time maintaining the contact speed necessary to withstand recovery voltage. When the current waveform crosses zero, the arc becomes relatively weak. At this point, the pressurized SF6 gas flows from the Auto-Puffer TM volume through the nozzle extinguishing the arc. When interrupting low currents, Auto-Puffer TM interrupters act in much the same way as puffer interrupters. That is, there is not sufficient gas pressure generated to force the Auto-Puffer TM valve closed. Thus, the fixed Auto-Puffer TM volume and puffer volume form one large puffer volume. In such a case, the SF 6 gas pressure required for interruption is built up by mechanical means as in a puffer interrupter. Unlike a puffer nterrupter, however, Auto-Puffer TM need only mechanically generate sufficient gas pressure to interrupt a portion of the rated short-circuit current (i.e. 20% to 30%) In the open position, there is sufficient distance between the stationary and moving contacts to withstand rated dielectric levels. On closing, the refill valve opens so that SF 6 gas can be drawn into the Auto-Puffer TM and puffer volumes.because interruption of low currents requires only moderate build up of SF 6 gas pressure by mechanical means and since high current interruption uses heating from the arc to generate necessary gas pressure in a fixed volume, Auto- Puffer TM interrupters require far less operating energy than puffer interrupters (i.e. about 50% less). ABB Auto-Puffer TM interrupter is also a single motion design. 3

6 Design Features and Advantages LTB FAMILY Design Features LTB Design Features and Advantages LTB is available for single- or three-pole operation. For circuit breakers with one breaking element per pole, both modes of operation are possible. For three-pole operation, the circuit breaker poles and the operating mechanism are linked together with pull rods. On every pole there is an individual opening spring controlled by the pull rod. There is however one exception. In the LTB D three-pole operation case there is only one opening spring cntrolling all three poles and it is mounted on the pole furthest away from the operating mechanism. Each circuit breaker pole constitutes a sealed SF 6 filled unit, which includes the breaking unit, the hollow post insulator and the mechanism housing Circuit Breaker type LTB D 1. Breaking Chamber 2.Support Insulator 3.Support Structure 4.Operating Mechanism type BLK 5. Trip Spring 6.Gas Tube with Protective Beam 7.Gas Supervision (On opposite side) 8. Drilled Holes for Connection to Ground 9. Pull rod with Protective Tube 10. Position Indicator Note: 5, 6,9 are inside the horizontal beam 4

7 LTB FAMILY Design Features and Advantages The three poles of the circuit breaker can be mounted on individual pole supports or in the case of LTB D on a common support frame (pole beam). BLK is used for: LTB D kv LTB E kv Single-pole operation BLG is used for: LTB E kv Three-pole operation The operational reliability and the service life of an SF 6 circuit breaker is very much dependent on the ability to ensure sealing of the SF 6 gas volume and to neutralize the effects of moisture and decomposition products in the gas. The risk for gas leakage is negligible; double nitrile rubber O-rings and X-rings are used with excellent result. Dielectric Strength LTB has high dielectric strength even at atmospheric SF 6 pressure, due to optimized contact gap. Controlled Switching As option LTB circuit breakers can be used for controlled switching by applying our controlling device type Switchsync TM.For further information please see chapter O-1 Controlled Switching. Stable Operating Times For controlled switching it is of the utmost importance that the functional times for closing and tripping operations are constant. We can guarantee 1 ms for all LTB circuit breakers. Each breaking unit is provided with a desiccant, which absorbs the moisture and the decomposition products from the interruption process. Since the interrupting capability is dependent on the density of the SF 6 gas, the LTB circuit breaker is provided with a density monitor.the density monitor consists of a temperature compensated pressure switch. Therefore, alarm signal and blocking function are activated only if the pressure drops due to leakage. The design corresponds with the demands in the standards IEC and ANSI. Special design solutions to meet other standards and/or specifications are also available. Current Switching Capability All LTB circuit breakers are capable of interrupting short-circuit currents in a maximum of 40 ms. We can also guarantee restrike free interruption of capacitive currents due to optimized contact design and movement. For inductive current switching the over-voltages are low as a result of optimum quenching at current zero. 5

8 Design Features and Advantages LTB FAMILY Material Seismic Withstand Strength The selected components of aluminum (mechanism housings, HV-terminals, cubicles) give a high degree of resistance to corrosion, without the need of extra protection. For use in extreme trying environments LTB can be delivered with a protective painting. The support structure and protective tubes for the pull rods are made of hot-dipped galvanized steel Insulators LTB circuit breaker is as standard delivered with insulators that consist of high-grade brown-glazed porcelain or composite insulators (light gray). LTB with light gray porcelain can be delivered on request. LTB is available as standard with long creepage distances. All LTB circuit breakers can in their standard versions, withstand seismic accelerations up to 3 m/s2 (0.3 g), LTBD up to 5 m/s2 in accordance with IEC 1166 and IEEE 693. Rating Plates A rating plate, which includes data for the circuit breaker, is placed on the operating mechanism cubicle. The rating plate is made of stainless steel with engraved text. Operating Mechanism The circuit breaker is operated by motor charged spring operating mechanism(s), which is installed in a compact splash proof and corrosion resistant housing, attached to the structure. Longer creepage distances can be quoted on request. One BLK is used for three-pole operation for LTB D kv. Mechanical Strength The mechanical durability gives a sufficient safety margin for normal wind loads and static and dynamic forces from conductors. Three BLK s are used for single pole operation for LTB D kv. Three BLK s are used for single pole operation for LTB E up to 245 kv. One BLG is used for three-pole operation for LTB E up to 245 kv. 6

9 LTB FAMILY Design Features and Advantages Sealing Systems for SF 6 Volume The sealing system consists of double nitrile rubber O-rings in all static seals and double X-rings in all dynamic seals. This type of sealings has been used in our circuit breakers for more than 30 years with excellent service record at varying climatic conditions. The SF 6 gas leakage is less than 0.5% per year. SF 6 Density Monitoring Since the interrupting capability is dependent on the density of the SF 6 gas, the LTB circuit breaker is provided with density monitor(s). All LTB E circuit breakers have one density monitor per pole. The density monitor consists of a temperature compensated pressure switch. Therefore, alarm signal and blocking function are activated only if the pressure drops due to leakage. The standard version of LTB D for kv has one common density monitor for all three poles. Alternatively LTB D can be provided with one density monitor per pole. Climatic Withstand The LTB circuit breakers are designed for, and are installed in, widely shifting conditions from polar to desert climate throughout the world. For circuit breakers installed in areas with extreme low temperatures there is a risk of condensation of the SF 6 gas. In order to avoid condensation consequences, one of the following gas-mixtures is used: SF 6 and N 2 SF 6 and CF 4 7

10 Design Features and Advantages LTB FAMILY Support Structure Support structures are included in the standard versions of the LTB circuit breakers. The support structures are made of hot-dipped galvanized steel. The standard versions for structures are: LTB D kv One support column per D=14(4X) LTB E all types One support column per pole For detailed information see Dimensions 338 The support structures are prepared for connection to ground by means of drilled holes on each leg. High Terminals Drilled holes for connection The LTB circuit breakers are as standard equipped with flat aluminum terminals with thickness 20 mm for LTB D and 28 mm for LTB E. The drilling pattern is in accordance with IEC and NEMA standards. Other dimensions (e.g. DIN) by means of adapters, are available on request. Circuit breakers with vertically mounted breaking elements have terminals on both sides for connection in either direction. Circuit breakers with horizontal breaking elements have one terminal per breaking element. The terminals are directed upwards Ø14.5(13X)

11 LTB FAMILY Design Features and Advantages Controlled Switching Devices The goal for controlled switching is to increase power quality in the network systems by reducing switching transients. All LTB circuit breakers are suitable for controlled switching with ABB s Switchsync TM device. In order to obtain optimum result the switching instants should be different for the three phases. For three-pole operated circuit breakers this is achieved with mechanically staggered poles. Presently more than 1,000 HV live tank circuit breakers manufactured by ABB are in operation with controlled switching. Type Tests The LTB circuit breakers have been type tested in accordance with IEC and/or ANSI standards. Type test reports can be presented on request. Routine Tests All LTB circuit breakers are routine tested before delivery. Our test program complies with IEC and ANSI standards. Transport The LTB circuit breakers are normally packed and transported in seaworthy wooden crates.the circuit breaker poles with one breaking element per pole are transported as com-plete units. For circuit breakers with two breaking elements per pole, the breaking elements and the support insulators are transported in two separate cases. For detailed information regarding weights and dimensions see Shipping data. Breaking elements as well as support insulators are filled with SF 6 gas at a slight overpressure. Arrival Inspection On arrival the packaging and contents should be checked against packing list. In the event of damage to the goods, contact ABB for advice, before further handling of the goods takes place. Any damage ought to be documented (photographed). SF 6 gas Gas for filling up to rated pressure can be delivered in bottles, each containing 40 kg gas. The quantity required for each type of LTB varies from one circuit breaker type to an-other. This information is given in the tender. The pressurizing equipment can be delivered on request, and is described under Erection and Commissioning. 9

12 Design Features and Advantages LTB FAMILY Erection and Commissioning Assembly instructions are provided with each delivery. Erection work at site can be done in 1-4 days depending on LTB type and size. Filling of SF 6 gas to specified rated pressure is done by using the following pressuri-zing equipment, which can be delivered on request: One special control valve, for connection to the gas bottle, and a 20 m gas-filled hose with connectors. A complementary control valve for connection to CF4 or N2 gas bottle (for mixed gas filling). When using above equipment gas filling can be carried out without gas being released into the atmosphere. For illustration of gas filling equipment see page I-6. Maintenance LTB is designed for a service life of more than 30 years or 10,000 mechanical operations. For current switching the number of operations before service is dependent on the interrupted current and type of application. Inspection, maintenance and overhaul should be carried out at regular intervals de-pending on the ambient conditions and the number of operations. The general actions are described below: 1-2 years: Ocular inspection 7-10 years or 2,000 mechanical operations: Extended ocular inspection and some lubrication of the operating mechanism(s) years or 5,000 mechanical operations Preventive maintenance including general inspection of the circuit breaker and operating mechanism. Operation test including measurement of operating times and possible adjustments. 30 years or 10,000 mechanical operation: A comprehensive inspection is recommended to give increased safety and continued problem-free operation. The inspection methods and scope depend very much on the local conditions. For circuit breakers for special switching duties such as switching of reactor banks overhaul of the breaking chamber should be carried out more frequently, approximately 5,000 operations Overhaul and repair work must be performed by authorized personnel only. The instructions in the manual for operation and maintenance should be observed. ABB is available for discussions and advice. 10

13 LTB FAMILY Design Features and Advantages Recommended Spare Parts High operation frequency (e.g. circuit breakers for reactor or capacitor switching) and/or large quantities of circuit breakers: Complete poles Complete operating mechanisms Sets of contacts Sets of gaskets Density switches SF 6 gas Disposal The disposal of wasted parts should be carried out in accordance with local legal provisions. The SF 6 gas should not be released into the atmosphere when the circuit breaker is scrapped. The SF 6 gas can be recycled. The porcelain can, after it has been crushed, be used as fill. The metals used in the circuit breaker can be recycled. 11

14 Technical Data LTB FAMILY Technical Data According to ANSI LTB 72.5D1/B LTB 145D1/B LTB 170D1/B LTB 72.5E1 LTB 170E1 LTB 245E1 Number of breaks per pole Rated voltage kv Rated frequency Hz Power frequency withstand voltage - To earth (Dry/Wet) kv 160/ / / / / /350 -Across open pole(dry/wet) kv 160/ / / / / /350 Lightning Impulse Withstand - To earth kv Across open pole kv Chopped Wave Impulse Withstand To earth (2 s) kv Across open pole(2 s) kv Switching Impulse Withstand - To earth and/between phases kv Across open pole kv Creepage distance mm/kv Rated normal current A Rated s.c current ka First-pole-to-clear factor Rated closing and latching current ka Duration of short time withstand circuit s Closing time ms < 40 < 40 < 40 < 55 < 55 < 55 Opening time ms Break time ms Dead time ms Rated Standard Operating Duty - O-0.3s-CO-3min-CO or CO-15s-CO 12

15 LTB FAMILY Technical Data Technical Data According to IEC LTB 72.5D1/B LTB 145D1/B LTB 170D1/B LTB 72.5E1 LTB 170E1 LTB 245E1L Number of breaks per pole Rated voltage kv Rated frequency Hz Power frequency withstand level 1) - To earth and between phases kv Across open pole kv Lightning Impulse Withstand Level(LIWL) - To earth and between phases kv Across open pole kv Switching Impulse Withstand Level(SIWL) - To earth and/between phases kv Across open pole kv Creepage distance mm/kv Rated normal current A Rated s.c breaking current ka First-pole-to-clear factor Making current peak ka Duration of short circuit s Closing time ms < 40 < 40 < 40 < 55 < 55 < 55 Opening time ms Break time ms Dead time ms Rated Operating Sequence - O-0.3s-CO-3min-CO or CO-15s-CO 13

16 Dimensions-LTB LTB FAMILY Dimensions-LTB Dimensions -LTBD LTB D1/B Two-Column Stand, Three-pole Operation Rated : kv Dimensions(mm) Rated A B C D E F 72.5 kv kv kv Available dimensions for phase distances and heighes to lowest part of insulator(mm) E F E 267 Rated phase distances B 72.5 kv 1050* 1500* 1750* kv * kv A C *) Standard **)BIL550kV ated Height to lowest part of insulator** D 72.5 kv * *) Standard 2530 **) Other dimensions can be provided LTB D1/B Three-Column Stand, Three-pole Operation Rated : kv Dimensions(mm) Rated A B C D E F 72.5 kv kv F 170 kv E E 267 Available dimensions for phase distances and heighes to lowest part of insulator(mm) B Rated phase distances 72.5 kv 1050* 1500* 1750* kv * kv A C D *) Standard **)BIL550kV Rated Height to lowest part of insulator** kv * *) Standard **) Other dimensions can be provided 14

17 LTB FAMILY Dimensions-LTB Dimensions --LTBE LTB E1 Three-pole Operation Rated : kv Dimensions(mm) Rated A B C D E F 72.5 kv kv kv Available dimensions for phase distances and heighes to lowest part of insulator(mm) Rated phase distances 72.5 kv 1100* kv * kv *) Standard Rated Height to lowest part of insulator** kv * *) Standard LTB E1 Single-pole Operation Rated : kv Rated A B C D E F 72.5 kv kv kv *)Recommended phase distances Available dimensions for phase distances and heighes to lowest part of insulator(mm) Rated Height to lowest part of insulator** kv * *) Standard 15

18 Shipping Data for LTB D LTB FAMILY Shipping Data for LTB Shipping Data for LTBD LTB 72.5D1/B,Three-pole Operated, Three-Column Stand Equipment Number of Dimensions Gross Weight cases L x W x H (m) (Kg) Breaker Poles x 1.78 x Operating mechanism x 1.05 x Support Structure x 0.58 x Total m LTB 145D1/B,Three-pole Operated, Three-Column Stand Equipment Number of Dimensions Gross Weight cases L x W x H (m) (Kg) Breaker Poles x 1.78 x Operating mechanism x 1.05 x Support Structure x 0.58 x Total m LTB 170D1/B,Three-pole Operated, Three-Column Stand Equipment Number of Dimensions Gross Weight cases L x W x H (m) (Kg) Breaker Poles x 1.78 x Operating mechanism x 1.05 x Support Structure x 0.58 x Total m LTB 170D1/B,Three-pole Operated, Three-Column Stand Equipment Number of Dimensions Gross Weight cases L x W x H (m) (Kg) Breaker Poles x 1.78 x Operating mechanism x 1.05 x Pole Beam x 0.57 x Support Structure x 0.58 x Total m LTB 145D1/B,Three-pole Operated, Three-Column Stand Equipment Number of Dimensions Gross Weight cases L x W x H (m) (Kg) Breaker Poles x 1.78 x Operating mechanism x 1.05 x Pole Beam x 0.57 x Support Structure x 0.58 x Total m LTB 170D1/B,Three-pole Operated, Three-Column Stand Equipment Number of Dimensions Gross Weight cases L x W x H (m) (Kg) Breaker Poles x 1.78 x Operating mechanism x 1.05 x Pole Beam x 0.57 x Support Structure x 0.58 x Total m

19 LTB FAMILY Shipping Data for LTB E Shipping Data for LTB Shipping Data for LTBE LTB 72.5 and 170E1,Three-pole Operated, Three-Column Stand Equipment Number of Dimensions Gross Weight(Kg) cases L x W x H (m) LTB 72.5 Breaker Poles 1 on request on request - LTB 170 Breaker Poles x 1.90 x Operating Mechanism x 0.97 x Support Structure x 1.10 x LTB on request on request - LTB m LTB 72.5 and 170E1,Single-pole Operated, Three-Column Stand Equipment Number of Dimensions Gross Weight(Kg) cases L x W x H (m) LTB 72.5 Breaker Poles 1 on request on request - LTB 170 Breaker Poles x 1.90 x Operating Mechanism x 1.17 x Support Structure x 1.10 x LTB on request on request - LTB m LTB 245 E1-Three-pole Operated Equipment Number of Dimensions Gross Weight(Kg) cases L x W x H (m) Breaker Poles x 1.90 x Operating Mechanism x 0.97 x Support Structure x 1.10 x Total m LTB 245 E1-Single-pole Operated Equipment Number of Dimensions Gross Weight(Kg) cases L x W x H (m) Breaker Poles x 1.90 x Operating Mechanism x 1.17 x Support Structure x 1.10 x Total m