Know in Details about the Air Circuit Breaker

Posted by Meba Electric on February 10th, 2021

Normally, in our office or home, we are not used to seeing fire blazing or accidental explosions when there are any other faults in the electrical system or when the current jumps above the safe level. The circuit breaker cuts the power to the electrical system when these accidental incidents are about to happen.

Because of other mayhem and the potential for fires resulting from simple equipment failures and wiring problems without circuit breakers from DC Breaker Manufacturer, household electricity would be impractical. Either in the electrical distribution systems or in the primary source of electricity, it is one of the most important safety mechanisms from where in our home, electricity is distributed.

Air circuit breaker: Causing an electrical arc to be generated, when the breaker opens the current flow is interrupted. So that the gap between the contacts can again withstand the voltage in the circuit, this arc is extinguished and cooled in a controlled way. To restore power to the interrupted circuit, the contact is again closed when the fault condition is fixed. The circuit breaker is called air circuit breaker (ACB) when to extinguish the arc, a circuit breaker uses compressed air.

Construction: 3 types of contacts are contained in each phase of a three-phase Air Circuit Breaker (ACB), namely; the arcing horn, arcing contacts and main contacts carrying the load current.

Closing cycle: The arcing contacts touch first to make the circuit again in the closing cycle. Then the main contacts enable the circuit to flow electrical current and close.

Arcing Contacts: Since arcing contacts are provided and no arcing must occur at the main contacts, which break or make the circuit current.

The main contacts: The load current is carried by the main contacts under normal operation. Therefore, to prevent overheating, when current is flowing through it, main contact resistance must be low enough. A good conducting material such as copper, silver or copper with silver plating is used to make up the main contacts. They can be damaged if arcing occurs since these metals have relatively lower melting points. The main contacts do not break or make the current to prevent this damage.

Opening cycle: The load current is conducted by the low resistance main contacts when the RCD Circuit Breaker is closed. But, the main contacts transfer the current after opening first and to the arcing contacts when the breaker opens. Across the arcing horns, the arcing contacts open and an arc are established. The arc enters the arc chute and rises to the top of the arcing horns where in the cooling plates; it is rapidly cooled by heat transferring mechanism. Making it unable to conduct electricity, Cooled gas deionizes and arc is extinguished consequently.

Operating mechanism: in the air circuit breaker, to understand the sequence of operation of various contacts one must realize that at the main contacts, arcing must never occur.

Over the other circuit breakers, benefits of Air Circuit Breaker (ACB):

• Simple installation
• Relatively inexpensive
• Simple maintenance requirements
• Simple construction