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Air Circuit Breaker                                                                             intelligent



                                 Wrinciple of KperaƟon of Air Circuit Breaker



              The working principle of Air Circuit breaker is rather dif-   LJ ƐƉůŝƫŶŐ ƚŚĞ ĂƌĐ ŝŶƚŽ Ă ŶƵŵďĞƌ ŽĨ ƐĞƌŝĞƐ ǁŝůů ŝŶĐƌĞĂƐĞƐ
              ferent from other types of circuit breaker. The main aim   the arc voltage.
              of circuit breaker is to prevent reestablishment of arcing   Arc voltage can be increased by lengthening the arc path.
              ĂŌĞƌ ĐƵƌƌĞŶƚ njĞƌŽ ǁŚĞƌĞ ƚŚĞ ĐŽŶƚĂĐƚ ŐĂƉ ǁŝůů ǁŝƚŚƐƚĂŶĚ   As soon length of arc path is increased the resistance
              the system recovery voltage. It does it same work, but in   path will increase more arc voltage is applied across the
              Ă ĚŝīĞƌĞŶƚ ŵĂŶŶĞƌ͘  ƵƌŝŶŐ ŝŶƚĞƌƌƵƉƟŽŶ ŽĨ ĂƌĐ͕ ŝƚ ĐƌĞĂƚĞƐ   arc path hence arc voltage is increased.
              an arc voltage instead of supply voltage. Arc voltage is   It is operated within voltage level up to 1 KV. It contains
              ĚĞĮŶĞĚ ĂƐ ƚŚĞ ŵŝŶŝŵƵŵ ǀŽůƚĂŐĞ ƌĞƋƵŝƌĞĚ ĨŽƌ ŵĂŝŶƚĂŝŶ-   two pairs of contact. The main pair carries the current
              ing arc .The circuit breaker increases the voltage in three   ĂŶĚ ƚŚĞ ĐŽŶƚĂĐƚ ŵĂĚĞ ŽĨ ĐŽƉƉĞƌ͘  Ŷ ĂĚĚŝƟŽŶĂů ƉĂŝƌ ŽĨ
              ĚŝīĞƌĞŶƚ ǁĂLJƐ͗                                         contact is made of carbon. When the breaker is opened,
              Arc voltage can be increased by cooling arc plasma. As   ƚŚĞ ŵĂŝŶ ĐŽŶƚĂĐƚ ŽƉĞŶƐ ĮƌƐƚ͘  ƵƌŝŶŐ ŽƉĞŶŝŶŐ ŽĨ ƚŚĞ ŵĂŝŶ
              ƐŽŽŶ ĂƐ ƚŚĞ ƚĞŵƉĞƌĂƚƵƌĞ ŽĨ ĂƌĐ ƉůĂƐŵĂ ŵŽƟŽŶ ŽĨ ƉĂƌƟĐůĞ   contact, the arc contact remains in touch with each other.
              in arc plasma is reduced, more voltage gradient will be   dŚĞ ĂƌĐŝŶŐ ŐĞƚƐ ŝŶŝƟĂƚĞĚ ǁŚĞŶ ĂƌĐ ĐŽŶƚĂĐƚƐ ĂƌĞ ƐĞƉĂƌĂƚĞĚ͘
              required to maintain the arc.                          The circuit breaker is obsolete for medium voltage.


              Advantages of Air-Blast Circuit Beaker


               ŝƌ ďůĂƐƚ ĐŝƌĐƵŝƚ ďƌĞĂŬĞƌ ŝƐ Ă ƐƵŝƚĂďůĞ ŽƉƟŽŶ ƚŽ ƵƐĞ   ^ƉĞĞĚ ŽĨ ĐŝƌĐƵŝƚ ďƌĞĂŬĞƌ ŝƐ ŵƵĐŚ ŚŝŐŚĞƌ ĚƵƌŝŶŐ ŽƉĞƌĂ-
              ǁŚĞƌĞ ĨƌĞƋƵĞŶƚ ŽƉĞƌĂƟŽŶ ŝƐ ƌĞƋƵŝƌĞĚ ďĞĐĂƵƐĞ ŽĨ         ƟŽŶ ŽĨ ƚŚĞ Ăŝƌ ďůĂƐƚ͘
              lesser arc energy                                      Arc quenching is much faster
              dŚĞ ƌŝƐŬ ŽĨ ĮƌĞ ŝƐ ĞůŝŵŝŶĂƚĞĚ ŝŶ ƚŚĞ ŽƉĞƌĂƟŽŶ ŽĨ  ŝƌ   dŚĞ ĚƵƌĂƟŽŶ ŽĨ ƚŚĞ ĂƌĐ ŝƐ ƐĂŵĞ ĨŽƌ Ăůů ǀĂůƵĞƐ ŽĨ ĐƵƌ-
              blast circuit breaker.                                 rent.
              Air blast circuit breaker is small in size, because of the   ^ƚĂďŝůŝƚLJ ŽĨ ŽƉĞƌĂƟŽŶ ĐĂŶ ďĞ ŵĂŝŶƚĂŝŶĞĚ ĂŶĚ ĚĞƉĞŶĚƐ
              ŐƌŽǁƚŚ ŽĨ ĚŝĞůĞĐƚƌŝĐ ƐƚƌĞŶŐƚŚ ŝƐ ƐŽ ƌĂƉŝĚ ;ǁŚŝĐŚ ĮŶĂů   ŽŶ ƐƉĞĞĚ ŽƉĞƌĂƟŽŶ ŽĨ ĐŝƌĐƵŝƚ ďƌĞĂŬĞƌƐ͘
              ĐŽŶƚĂĐƚ ŐĂƉ ŶĞĞĚĞĚ ĨŽƌ ĂƌĐ ĞdžƟŶĐƟŽŶ ŝƐ ǀĞƌLJ ƐŵĂůůͿ͘    It requires less maintenance.

                                                                               Disadvantages of Air-Blast

                                                                                        Circuit Breaker



                                                                             ͻ  dŚĞ Ăŝƌ ƐƵƉƉůŝĞƌ ƉůĂŶƚ ƌĞƋƵŝƌĞƐ ĂĚĚŝƟŽŶĂů
                                                                                 maintenance.
              /nternal ConstrucƟon                                           ͻ  It contains high capacity air compressor.
                                                                             ͻ  There is a chance of air pressure leakage
              of Air Circuit Breaker                                             ĨƌŽŵ ƚŚĞ Ăŝƌ ƉŝƉĞƐ ũƵŶĐƟŽŶ͘
                                                                             ͻ  There is chance of a high rate rise of re-strik-
                                                                                 ing voltage and current chopping.
              1.   ^ŚĞĞƚ ^ƚĞĞů ^ƵƉƉŽƌƟŶŐ ^ƚƌƵĐƚƵƌĞ
              2.   ƵƌƌĞŶƚ dƌĂŶƐĨŽƌŵĞƌ ĨŽƌ WƌŽƚĞĐƟŽŶ                          ͻ  dŚĞ Ăŝƌ ŚĂƐ ƌĞůĂƟǀĞůLJ ůŽǁĞƌ ĂƌĐ ĞdžƟŶŐƵŝƐŚŝŶŐ
                  Trip Unit                                                      ƉƌŽƉĞƌƟĞƐ͘
              3.  WŽůĞ 'ƌŽƵƉ ŝŶƐƵůĂƟŶŐ ďŽdž
              4.  Horizontal rare terminals
              5.  ϱĂ͘ WůĂƚĞƐ ĨŽƌ ĮdžĞĚ ŵĂŝŶ ĐŽŶƚĂĐƚƐ
              6.  ϱď͘ WůĂƚĞƐ ĨŽƌ ĮdžĞĚ ĂƌĐŝŶŐ  ŽŶƚĂĐƚƐ
              7.  ϲĂ͘ WůĂƚĞƐ ĨŽƌ DĂŝŶ ŵŽǀŝŶŐ ĐŽŶƚĂĐƚƐ
              8.  ϲď͘ WůĂƚĞƐ ĨŽƌ DŽǀŝŶŐ  ƌĐŝŶŐ ĐŽŶ-
                  tacts
              9. Arcing Chamber
              10. dĞƌŵŝŶĂů ďŽdž ĨŽƌ ĮdžĞĚ ǀĞƌƐŝŽŶ ʹ
                  ^ůŝĚŝŶŐ  ŽŶƚĂĐƚƐ ĨŽƌ ǁŝƚŚ ĚƌĂǁ ĂďůĞ
                  version
              11.  WƌŽƚĞĐƟŽŶ dƌŝƉ hŶŝƚ
              12. Circuit breaker Closing and Opening
                  Control
              13.  ůŽƐŝŶŐ ^ƉƌŝŶŐƐ


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