Merits and Demerits of Types of Conventional Circuit Breakers

Merits and Demerits of Types of Conventional Circuit Breakers: Having studied the operational principles, the constructional features and fields of application of the bulk oil, minimum oil and air-blast circuit breakers, it would be worthwhile to consider their relative merits and disadvantages of Conventional Circuit Breakers. (a) Bulk Oil Circuit Breakers: The main advantages of […]

Non Linear Resistance Shunts

Non Linear Resistance Shunts: Non Linear Resistance are especially suitable, both from space and reliability considerations for small shunt currents in conditions where wire-wound resistors tend to be less satisfactory on mechanical grounds. Where heavy currents are involved, there may be difficulty in accommodating the relatively large volume of resistor material that is required. Non […]

Linear Resistance Damping

Linear Resistance Damping: By introducing a linear resistance across the circuit breaker during interruption, the restriking transients are damped. Provision has to be made for subsequent interruption of the resistance circuit. Two such ways are shown in Fig. (15.27). In Fig. (15.27a) the resistor R is switched into circuit by the breakdown of the ionized […]

Performance of Circuit Breaker System Requirements

Performance of Circuit Breaker System Requirements: Analysis of circuit interruption and the foregoing discussion of various circuit breakers apply to circuit breakers in practice if they had ideal switching characteristics. The ideal circuit Breaker System has a negligible are vol­tage and has the ability to develop instantaneously infinite arc-gap resistance at natural current zero. In […]

Development of Airblast Circuit Breaker

Development of Airblast Circuit Breaker: The development of Airblast circuit breakers has taken place in three stages shown schematically in Fig. (15.19): Momentarily pressurized Airblast breakers with isomaker in the Momentarily pressurized air-blast breakers with isomaker in separate pressurized chamber. Permanently pressurized air-blast breakers with isomaker in separate pressurized chambers. In the first design air-blast […]