Bulk Oil Circuit Breaker Diagram. When the fault occurs in the system the contacts of the circuit breaker are open under the insulating oil and an arc is developed between them and the heat of the arc is. Following types of circuit breakers formerly used in high voltage outdoor substations are no longer in use and are being phased out.
Bulk oil circuit breaker or bocb is such types of circuit breakers where oil is used as arc quenching media as well as insulating media between current carrying contacts and earthed parts of the breaker. Minimum oil circuit breaker or mocb. These can be further divided into.
The oil used here is same as transformer insulating oil.
It is also called a dead tank circuit breaker. The quantity of oil requires in bulk oil circuit breaker depends on the system voltage. The figure below shows the cross section of a single phase minimum oil circuit breaker there are two compartments separated from each other but both filled with oil the upper chamber is the circuit breaking chamber while the lower one is the supporting chamber the two chambers are separated by a partition and oil from one chamber is prevented from mixing with the other chamber. It is also called a dead tank circuit breaker.
