20 amp 2 pole Miniature Circuit Breaker

Circuit Breaker Information

• Rated Current: 20 amp
• Rated Voltage: 230/400V AC, 50Hz
• Number of pole: 2 poles
• 6 kA short circuit breaking capacity
• Compliance with IEC standard
• C curve trip characteristic for short circuit and overload protection for different applications

Technical Data

Circuit Breaker Dimensions (Unit: mm)

Details

Tips: Arc extinguishing principle of the circuit breaker
Arc extinguishing is also one of the important applications of the circuit breaker, because arc not only damages the equipment circuit, but also affects human safety. Generally, there are four conventional arc extinguishing means, including the mechanical arc extinguishing, magnetic quenching and so on.

1. Mechanical arc extinguishing
   The arc is stretched long rapidly through the limitation equipment. Such a means is mostly used in the switch equipment.
2. Magnetic quenching
   Under an action of the magnetic field generated by the magnetic coil connected with the contact head in series, the arc is pulled long because of the electromagnetic force. It will be blown into the arc extinguishing cover constituted by the solid medium to contact with the solid medium. Then the arc is cooled and extinguished.
3. Narrow slit (longitudinal slit) arc extinguishing
   Under the electrodynamic force of the magnetic field formed by the arc, the arc will be pulled long and enter into the narrow (longitudinal) slit of the arc extinguishing cover. Several longitudinal slits will cut the arc into several segments and contact with the solid medium directly. As a result, the arc is extinguished soon. Such a structure is mainly used for the AC contactor.
4. Grid-plate arc extinguishing
   When the contact heads separate, the generated arc will be pushed into a group of metal grids, so as to be cut into several segments under the electrodynamic force. Every piece of mutually insulated metal grid is equivalent to an electrode. Therefore, there are many pressure reductions of positive and negative poles. As to the AC arc, there will be a dielectric strength of 150V~250V approaching to the negative pole when the arc exceeds zero, so that the arc will be extinguished instead of continuing to maintain. Therefore, AC apparatus usually employs the grid-plate arc extinguishing.