S&C TripSaver Dropout Recloser. For enhanced lateral circuit protection at 15 kv and 25 kv

Transcription

1 S&C TripSaver Dropout Recloser For enhanced lateral circuit protection at 15 kv and 25 kv

2 Introducing S&C s new TripSaver Dropout Recloser: A better solution for overhead lateral circuit protection at 15 kv and 25 kv Conventional lateral circuit protection requires some concessions Over 90% of temporary faults on overhead distribution circuits occur on laterals. Over the years, utilities have dealt with lateral protection a couple of ways. Some utilities employ a fuse blowing philosophy: The substation feeder breaker is properly coordinated with the lateral fuse, so that the fuse will clear any downstream fault within its rating... not the breaker. The problem: Service to customers on the lateral is permanently interrupted even for a temporary fault as shown in Figure 1. And the utility must deal with the high cost of service calls to replace lateral fuses. Feeder breaker Lateral fuse Feeder breaker Figure 2. Fuse saving philosophy. Figure 1. Fuse blowing philosophy. Lateral fuse Other utilities employ a fuse saving philosophy: The first trip of the substation feeder breaker is intentionally miscoordinated so that the breaker operates faster than the lateral fuse to clear a fault downstream of the lateral fuse. The second trip of the breaker is slower so that if the fault is still present, the lateral fuse will operate to clear it. The problem: All customers on the feeder experience a momentary interruption for all faults as shown in Figure 2. TripSaver provides better lateral protection S&C s new TripSaver Dropout Recloser eliminates these problems. It s ideally suited for protection of laterals that experience frequent momentary faults. This self-powered, electronically controlled, singlephase vacuum fault interrupter is available for installation in new or existing current-production ( -R10 ) S&C or MacLean Power Systems Type XS Fuse cutout mountings. A two-insulator, branch-feeder style mounting is also available. TripSaver eliminates the permanent outage which results when the lateral fuse operates in response to a momentary fault. Utilities using fuse blowing will see an improvement in SAIFI without sacrificing MAIFI. And TripSaver eliminates the momentary interruption on the feeder in instances where the breaker is tripped to save the lateral fuse during a momentary fault. Utilities using fuse saving will see an improvement in MAIFI without sacrificing SAIFI. As shown in the following table, TripSaver offers a number of advantages over traditional lateral protection devices. 2

3 Comparison of Lateral Protective Devices Feature/Benefit Single-Phase Hydraulic Recloser Dropout-Style Electronic Sectionalizer TripSaver Easy to install 4 4 Low initial price 4 4 Low installation cost 4 4 Fault-interrupting capability 4 4 Easy to reset 4 4 Electronic control 4 4 No bypass switch required 4 4 Light weight compared to oil reclosers 4 4 No battery backup required 4 4 Fits in cutout mounting 4 4 No momentary outage on the main feeder for lateral faults 4 4 TripSaver s operating sequence TripSaver features an open-close-open-dropout operating sequence with a 5-second reclosing time interval. The interrupter resets five seconds after dropout, ready for the next sequence. The first opening operation features very fast 1.5- to 5.0- cycle clearing time. The second opening operation features a time-current characteristic equivalent to either a K-speed or T-speed fuse curve. This operating sequence provides excellent coordination with the substation feeder breaker and downstream transformer fuses. 3

4 How TripSaver works for a temporary fault Consider a temporary fault downstream of TripSaver, as shown in Figure 3. TripSaver recloses, restoring power to customers served from the lateral, as shown in Figure 5. Since the fault was temporary and has gone away, a second opening operation isn t needed. TripSaver reverts to its fast curve after 15 seconds. Feeder breaker TripSaver Figure 3. Temporary fault. Figure 5. TripSaver recloses. As discussed on page 3, the first opening operation uses the fast curve. TripSaver opens, as shown in Figure 4. Only customers served from the lateral experience a momentary interruption. Figure 4. TripSaver opens. 4

5 How TripSaver works for a permanent fault Consider a permanent fault downstream of TripSaver, as shown in Figure 6. TripSaver recloses, as shown in Figure 8. Feeder breaker TripSaver Figure 6. Permanent fault. Figure 8. TripSaver recloses. As before, the first opening operation uses the fast curve. TripSaver opens, as shown in Figure 7. Again, only customers served from the lateral experience a momentary interruption. Since the fault is permanent, TripSaver opens again per the slow curve. Then TripSaver drops out in the same manner as a standard fuse cutout, providing visual indication that the faulted section of the feeder has been isolated, as shown in Figure 9. Figure 7. TripSaver opens. Figure 9. TripSaver drops out. 5

6 Handling TripSaver Overhead Pole-Top Style Shown TripSaver in dropout position Five seconds after TripSaver drops out, the vacuum fault interrupter closes. Closing TripSaver back into mounting TripSaver can be readily closed back into the mounting using a standard hookstick equipped with a distribution prong. Opening TripSaver with Loadbuster Tool If the lateral circuit needs to be de-energized, TripSaver can be opened using Loadbuster The S&C Loadbreak Tool. Construction Birdproof-design insulator higher insulation characteristics than ANSI distribution-cutout standards. Porcelain insulator shown; compositepolymer silicone insulator also available. NEMA Type B and extended mounting brackets are available too Parallel-groove connector tin-plated cast red brass. For ease of connection, accommodates two conductors, even of unlike size. Other types of connectors are also available Upper contact silver-to-silver; stainless-steel spring provides high contact pressure Rugged attachment hooks for Loadbuster guide TripSaver during closing Vacuum fault interrupter Lower contacts (not visible) silver-to-silver; provide dual current path, independent of hinge pivot Trunnion high-strength cast bronze, silver plated. Surfaces around trunnion bear on broad hinge surfaces to keep TripSaver in alignment during closing Mode selector for selecting automatic reclosing or non-reclosing operation. Non-reclosing mode has one-shot-to-lockout operation, suitable for use when crews are working downstream of the TripSaver Mode selector clip secures the mode selector in the non-reclose position Maintenance Unlike other single-phase reclosers, TripSaver requires no routine maintenance, field programming, or batteries for back-up power. 6

7 Ratings Complete TripSaver For new installations kv 50/60-Hz Ratings System Class Nom. Max BIL Cont. Overhead Pole-Top Style. Includes mounting (less mounting bracket and connectors) /25 a Branch-Feeder Style. Includes mounting (less connectors) /25 a Amperes, RMS1 Interr., Sym.2 Leakage Distance to Ground Minimum, Inches (mm) 8.5 (216) 11 (279) 17 (432) 11 (279) 17 (432) 17 (432)h TripSaver Less Mounting For installation in existing current-production ( -R10 ) S&C and MacLean Power Systems Type XS Fuse Cutout Mountings Item TripSaver For use with S&C Type XS Fuse Cutout Basic Catalog Number 50/60-Hz Ratings kv Amperes, RMS 1 System Class Nom. Max Cont , , 89032, 89042, , 89032, 89042, Minimum trip current is 2.4 times the continuous current rating. 2 Meets applicable sections of IEEE C a Applicable for protection of single-phase-to-neutral circuits only where the leakage distance to ground meets user s requirements. 15/25 a Interr., Sym. 2 h Leakage distance to ground is 24.2 inches (615 mm) for mountings with Cypoxy insulators. 7

8 Styles Catalog Number K100. Complete Overhead Pole- Top Style TripSaver rated 15 kv; 15.5 kv maximum; 110 kv BIL; 100 amperes continuous; 4000 amperes interrupting, RMS symmetrical; 8.5 inches (216 mm) leakage distance to ground. Catalog Number K100-P, featuring composite polymer silicone insulator. Complete Overhead Pole-Top Style TripSaver rated 25 kv; 29 kv maximum, 150 kv BIL; 100 amperes continuous; 4000 amperes interrupting, RMS symmetrical; 17 inches (432 mm) leakage distance to ground. Catalog Number K100. Complete Overhead Pole-Top Style TripSaver rated 25 kv nominal; 29 kv maximum, 150 kv BIL; 100 amperes continuous; 4000 amperes interrupting, RMS symmetrical; 17 inches (432 mm) leakage distance to ground. 8

9 Catalog Number E-K100 Complete Branch-Feeder Style TripSaver rated 15 kv nominal, 15.5 kv maximum, 110 kv BIL, 100 amperes continuous, 4000 amperes interrupting, RMS symmetrical, 17 inches (432 mm) leakage distance to ground. Catalog Number K100-P, featuring composite polymer silicone insulator. Complete Overhead Pole-Top Style TripSaver rated 15/25 kv nominal, 15.5 kv maximum, 125 kv BIL, 100 amperes continuous, 4000 amperes interrupting, RMS symmetrical, 11 inches (279 mm) leakage distance to ground. Ice Hood Option -H1, allows TripSaver to drop open with Z\v-inch ice build up. 9

10 Service soon indicator LED light Service soon indicator LED light gives advance notification that TripSaver is close to requiring service. Contact position indicator Position indicator provides indication of vacuum interrupter contact positions; Open/Closed Indicator (green for open, red for closed). 10

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12 Printed in U.S.A. Descriptive Bulletin May 10, 2010 Offices Worldwide f