Oil Circuit Breaker (ocb) – Types, Construction, Working and Applications ocb – Oil Circuit Breaker – Construction and Working Principle

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Cross Jet Explosion Pot
Such type of explosion pot is a modified form of plain explosion pot. It includes channels on one side of the pot that also acts as arc splitters. The arc splitter splits the arc increasing its length that helps in quenching the arc. The side channels are used for allowing a path for cool oil to enter the chamber and cool off the arc.

During fault conditions, the contacts start to separate and an arc is struck at the top portion of the pot. The arc heat vaporizes the oil generating pressure that exerts a force on the oil through the passage. When the moving contact moves further down, it unblocks the channel arc splitters. It splits the arc increasing its length that helps in quenching the arc at zero crossing.
Cross jet explosion pot is used for a very high current with a very low arcing time. it is not suitable for low current because low current cannot generate enough pressure to quickly quench the arc.
Self-Compensated Explosion Pot
This type of explosion pot is made from a combination of plain and cross jet explosion pot. It has two chambers; the upper chamber is a cross-jet explosion pot while the lower chamber is a plain explosion pot as shown in the figure.

If the fault current is very high, the pressure generated will be high. As soon as the moving contacts unblock the arc splitter ducts, the oil rushes out and the arc is split and extinguish.
If the fault current is low, the pressure builds slowly. As the moving contacts take time to pass through the throat, the pressure build-up inside the chamber. There is a little leakage through the arc splitter ducts. The arc successfully extinguishes in the lower chamber when the moving contact completely passes through the throat.
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