Oil circuit breaker OCB

An Oil Circuit Breaker (OCB) is a type of circuit breaker used to interrupt or break an electrical circuit in case of an overload or fault in the system. It operates by using oil as the insulating and quenching medium to cool down and extinguish the electric arc that occurs during the interruption of the current.

The OCB consists of a tank filled with oil, which acts as the dielectric material to insulate the contacts of the breaker. The oil also helps to dissipate the heat generated during the interruption process. The contacts of the OCB are made of copper or silver alloy, and are designed to open or close the circuit automatically or manually.

When a fault occurs in the circuit, the current passing through the contacts increases, which creates an electric arc between them. The electric arc produces heat, which ionizes the oil, making it conductive. This, in turn, causes a large amount of energy to be released, which is absorbed by the oil, leading to the quenching of the electric arc and interruption of the circuit.

OCBs are commonly used in high-voltage power systems and industrial applications due to their high breaking capacity, reliable performance, and ability to interrupt short-circuit currents. However, due to environmental concerns regarding the use of oil as an insulating medium, newer technologies such as Vacuum Circuit Breakers (VCBs) and Gas Insulated Switchgears (GIS) have become more popular in recent years.