240 likes | 730 Views
Premset 15 kV Compact modular vacuum switchgear Fixed circuit-breakers. Understand the choice of fixed circuit-breakers and the advantages they offer to customers Regarding environmental and installation conditions. Infrastructure Business Training. Expert: Jean-Marc Biasse
E N D
Premset15 kVCompact modular vacuum switchgearFixed circuit-breakers • Understand the choice of fixed circuit-breakers and the advantages they offer to customers • Regarding environmental and installation conditions Infrastructure Business Training Expert: Jean-Marc Biasse Coordinator: Christine Storck Pedagogy & Production: AMEG Duration: 7 min.
Characteristicsof withdrawable circuit-breakers • Disconnection of the main circuit by an extraction table • Equipped with sliding contacts • Circuit-breaker may be extracted using a tool
Characteristics of fixed circuit-breakers • Fixed contacts bolted to the main circuit require no lubrication or servicing • Smaller footprint
Background • Trend toward fixed circuit-breakers • Up until recently, withdrawable circuit-breakers were used because of easy maintenance and replacement. • Innovations eliminated appreciably reduced? the need to maintain and replace circuit-breakers. • The current trend is toward the use of fixed circuit-breakers for reasons that will be presented to you in next chapter.
Schneider Electric ranges examples of fixed CB switchgears SM6 GIS RingmasterGIS Premset GMA GeniEvo
Siemens: 8DJH ABB: Safe Plus Eaton: SVS Other manufacturers • Many competitors offer fixed circuit breakers: • Eaton: SVS • Siemens: 8DJH • ABB: Safe Plus
Historical reasons Maintenance of oil circuit-breaker in the past Sectionalising facility Test position to enable testing of the relay protection chain Maintenance and safety procedures Suitable for installations in electro-intensive industries Oil & Gas, minerals, metals and paper High fault levels due to the presence of MV motors I > 3150 A, Icc > 40 kA Frequency of switching Quick replacement of CB for critical applications High availability of field service personnel Why are withdrawable circuit-breakers challenging the usual established industry logic?
Reasons to move towardsMV fixed circuit-breakers Withdrawable CBs face specific failure risks if maintenance is not sufficient Overheating on sliding contacts if poor alignment between fixed & moving part Mechanical jamming of CB truck, shutters and associated interlock Poor electrical contact in the auxiliary switch connectors Higher reliability of fixed CBs High quality of bolted contacts, less sensitive to environment High reliability of vacuum interrupters Testbox device for periodic maintenance operations without CB removal
Future of MV circuit-breaker panel designchallenging the usual established industry logic Which unnecessary features taken for granted by the industry should be eliminated? Which features should be reduced below the industry standard? Which new values should be created that the industry has never offered? Which features should be raised well above the industry standard ? Withdrawability, O-0,3s-CO, Switch- fuse for MV/LV transformer protection Footprint, Corrective maintenance Harsh environment withstand, operator safety through internal arc withstand, switchgear life expectancy 100 A – 200 A optimized CBs for MV/LV transformer protection, dedicated cable testing devices, screened CTs and VTs
Fixed CB Benefits for customers Reinforced continuityof service • Proven reliability of vacuum interrupters • MTTF > 35,000 years (ceramic insulating body, sealed for life) • With fixed circuit-breakers in GIS and 2SIS systems, service life is longer • No deterioration due to environmental conditions
Modern fixed circuit-breakers with vacuuminterrupters require very low maintenance service. No more need to clean or lubricate contacts. The circuit-breaker is bolted on, avoiding exposure to air of sliding contacts. No more moving mechanisms (disconnecting contacts, shutters, truck), a potential cause of failure. Low maintenance Low cost A real reduction of maintenance requirements Low maintenance cost
Easy testing Testing as easy as with withdrawable devices Testing is done on the front panel, without any dismantling Mimic diagrams facilitate testing and display circuit-breaker status In some cases, an optional accessory may be used for primary injection without disconnecting the breaker Earthing switch operation Circuit-breakeroperation Standard: testing by secondary injection Premset mimic diagram
Normal conditions class Favorable conditions clean and dry trench, absence of dust, stable temperature, no humidity, no vegetation around, not in a coastal area, … > Modular AIS switchgear with withdrawable CB Resistance environment • Depending on • application fields • environmental conditions • installation conditions • Different levels of withstand • Dust • Pollution • Temperature changes causing condensation • Humidity • Aggressive conditions class • Poor installation conditions • combined with special • Environment • humidity-condensation, • dust, other deposit, • water in cable trenches, • salty, polluted atmosphere, … > GIS & 2SIS switchgear with fixed CB • Severe conditions class • Less favourable & more • sensitive conditions • close to sea, • close to dusty area, • … > Modular AIS switchgear with withdrawable CB if decent installation conditions
Main points to remember Fixed circuit-breakers offer many advantages for customers: • Smaller footprint • Simple operating modes and testing • Reduced maintenance requirements • Improved continuity of service • High resistance to difficult environmental conditions Schneider Electric - Energy Business Training - Premset: Fixed circuit breakers – October 2012 18
Infrastructure Business training Thank you! Do you want to know more about Schneider Electric, our offering and solutions? Then take some time to visit our website http://www.schneider-electric.com Schneider Electric - Energy Business Training - Premset: Fixed circuit breakers - October 2012 19