Jagannath Electricals

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Circuit breakers are classified into various types based on the arc quenching medium used. Jagannath Electricals initially manufactured miniature circuit breakers which used only air as the quenching medium. Bulk Oil circuit breakers, which are high voltage circuit breakers use oil as the arc quenching media.

The fixed contact, the moving contact, gas expansion chamber and arc chamber are the main components of the circuit breaker and they are composed of small metallic parts. Jagannath Electricals used oxidized aluminium particles for making of its contacts. These particles of aluminium are mixed within a non-conductive binder like silicon cements, Bakelite or rubber based on the rating of the circuit breaker to be manufactured. A curing catalyst is added to this mixture to harden it and increase its life so that it can withstand more number of overcurrents without damaging the contacts.

The moving contacts are connected by a piston and piston moves with the tension rod. The tension rod and piston are immersed in oil completely. The fixed contact is connected with copper conductor and the bushings are made by insulator that are connected in series with each other. The insulating oil was required in large quantities for BOCB as it had to cover both the contacts and piston. From moving to BOCB to MOCB, technology upgradation to the tune of was required but it would include substantial savings in oil as oil is used only for arc quenching and not for insulation purposes in MOCB.

While, moving from manufacturing of BOCB to SF6 , design changes in the manufacturing process of circuit breaker were not required but a facility for producing SF6 through electrolysis process was required. It is manufactured by reaction of fluoride, obtained by electrolysis, with sulphur. This was the only additional fixed cost that had to be incurred by Jagannath Electricals to fulfil F&T’s proposal. SF6 circuit breakers use the SF6 gas as the arc quenching medium and were extremely efficient and effective in their operation. The probability of the circuit catching fire in short circuits was almost nil with the usage of this type of circuit breaker.

But, SF6 was identified as a greenhouse gas and many countries were in the process of banning its release in the atmosphere for safety reasons. Although, Indian market was not very stringent in pollution norms, chances of the regulations being imposed by Indian authorities on circuit breaker manufacturers could not be discarded.