Air Circuit Breakers - Industrial Products

Tech Articlesintered metal tips of 50% silver and 50%tungsten on copper conductors. The maincontact tips thus provide a high degree ofconductivity and desired hardness, resultingin low temperature rise at the same timeretaining a high mechanical and electricalendurance capability.Flexible ConnectorsIt has been observed that the flexibleconnectors made out of copper braidedwires plated with tin or silver often loosetheir flexibility or get welded together whenexcessive heating is caused by short circuitcurrents. Also the rubbing of braided wirescauses deterioration in flexibility andconductivity. In TITANIA-ACB, a bunch ofcopper strips (foils) having 99.96 % purity,with their ends fuse welded is used asflexible connectors. Since the melting pointof pure copper is very high , the chances offlexible connectors loosing there flexibilityor getting welded are totally eliminated,while maintaining desired rigidity to achievefull advantage of compensation principle.Arc ChuteThe arcing time and consequently breakingcapacity of a breaker also depends on thedesign of the arc chutes. It is the design ofarc chute which determines as to howquickly and effectively the arc can bequenched and the energy released in theform of hot ionized gases can be dissipatedand removed without influencing otherparts of the breaker.The design of de-ion grids in arc chute ofTITANIA-ACB has been so arranged thatthese engulf the triangular shape arc hornfrom two sides and thus arc is scattered in amuch larger area.Isolating BarriersFurther the arc chute and the insulatedbarrier around the contact mechanismpractically seals the arcing area and thus thehot ionized gases escape only in upwarddirection at a great speed. The othermechanism of the breaker thus remains unaffectedfrom these ionized gases andbreaker is complete by free from shockhazards.Auxiliary Isolating ContactsIn TITANIA-ACB design, the auxiliaryisolating contacts are located on top of thebreaker providing full accessibility evenwhen breaker is in housed condition. Theterminal block on the front side, facilitatingeasy inspection and termination of wires.This unique design of auxiliary isolatingcontacts of TITANIA-ACB not onlyguarantees the fault less control supply tothe breaker but completely eliminatesservicing and maintenance problems.Microprocessor based over current trip devices.The trip device is located right in front of theACB providing precise current and timesetting facility. It requires no extra powerand has a built in operation check function.One piece rigidly mounted polyester resinmoulded current transformers adds to itsreliable tripping operation. Due to its mostaccurate and reliable operation, the highestdegree of system protection co-ordinationcan be achieved.Microprocessor based OCR providesfacilities for over load, short circuit,instantaneous trip and earth faultprotection.ACCESSORIES OF THE BREAKERELECTRICAL ACCESSORIES:Charging Motor:It is provided in anelectrical operatedACB to charge theclosing springsautomatically.These areavailable in 110Vand 220V AC/DC.The VA burden of this motor is 150 VA onlyand the charging time is 3 to 4 seconds.Shunt Trip Coil / Closing CoilThese coils are used for electrical trippingand closing of ACB. These coils are144 PURCHASE December 2012