Resources and Tools

Tuesday, October 4, 2011

How to Bow Fire occurred in Circuit Breaker

How to Bow Fire Occurred in Circuit Breaker? At the time of termination or a circuit linking the power systems (circuit breaker) will occur arc, it happens because at the time of circuit breaker contacts are separated, the potential difference between the contacts will cause the electric field between the contact , as shown in the picture below.

The current that previously flowed to the contact will heat up the contacts and produce thermic emission at the contact surface. While the electric field of high field emissions led to contact the cathode (K). Both of these emissions are produced free electrons are very much and move toward the anode contact (A). These electrons hit the media a neutral molecule of positive isolation of the region, these collisions will cause the ionization process. Thus, the number of free electrons to the anode will be growing and emerging results of ionization of positive ions moving toward the cathode, transfer of free electrons to the anode current rise and heat the anode contact.

Positive ions arriving at the cathode contact will cause two different effects. If contact is made of high melting point materials, such as tungsten or carbon, then the positive ions will be cause heating at the cathode. As a result, emissions increased thermic. If contact is made from low melting point material, eg copper, positive ions will cause high field emission. The results of this thermic emissions and high field emissions will perpetuate the ionization process, so that the charge transfer between the contacts continued and is called the arc.

To extinguish the arc is necessary efforts that could cause deionization process, among others the following manner:

1. Blow air into the sidelines of contact, so the particles ionisai results kept out of contact between.
2. Oil spraying insulation into the arc to give greater opportunities for recombination processes.
3. Arc cutting with a veil of isolation or metal screens, giving greater opportunities for recombination processes.
4. Create a contact separation medium of electronegative gases, so that free electrons captured by neutral gas molecules.

If the reduction of charged particles due to deionization process more than the addition of the charge due to the ionization process, then the arc will be extinguished. When the arc goes out, in between the contacts will remain the electric field exposure. If an exposure occurs when the electric field that is greater than the dielectric strength of insulating media contacts, the arcing will occur again.


Post a Comment

Related Posts Plugin for WordPress, Blogger...