**Basic Consideration for Design of Circuit Breakers:**

**Basic Design of Arc Extinction Chamber :** The considerations for design for the Arc Extinction chamber used in oil circuit breakers and air-blast circuit breakers would naturally be different. As far as the oil circuit breakers are concerned, the Basic Consideration for Design of Circuit Breakers of the arc extinguishing chamber would involve: Calculation of the arc voltage at various instances of time. A clear analysis of the process of gas formation under the influence of the arc. Calculation of pressure inside the Arc Extinction chamber due -to liberation of the gases. Velocity with which the gases move in the zone around the arc. Calculation of recovery voltage in the gap between …

**Basic Steps for Design of Circuit Breaker Types**** :** It is well known that a Circuit Breaker Types in an electrical power system has to perform the following four major operations. When the contacts are closed and the rated current passes, there should be least voltage drop across the contacts. When the contacts are open it should behave almost like an insulator. When under closed condition it is required to open its contacts, it should do so within the least possible time and without causing any dangerous disturbances like overvoltages to the system. Basic Consideration for Design of Circuit Breakers …

**Design of Current Carrying Capacity Systems**** :** The Current Carrying Capacity Systems of a circuit breaker consists not only of electrical conductors but also of mechanical devices like springs which do the dual job of passing the current as well as making and breaking contacts. In designing Current Carrying Capacity Systems it is, therefore, necessary to consider both the thermal problems like overheating and the electrodynamic problem due to the forces between conductors carrying current. For calculating the electrodynamic forces we require information of linear dimensions of each element in the current carrying system, their physical location with respect to each other and …

**Insulation Design of Circuit Breaker**** :** Insulation Design system of a circuit breaker requires solution of the following problems: Choice and calculation of the various clearances to be provided between the live parts and the dead parts in a circuit breaker. Calculation of voltages that will appear across each of the gaps in a multibreak system. Calculation of the minimum insulating levels to be provided for current carrying parts. The choice of clearances to be provided around the live parts in a circuit breaker depends upon a study of the probable paths of electrical discharge. Care must be taken in defining these parts to take into …