What is arc in circuit breaker
In a circuit breaker, an arc is a type of electrical discharge that occurs when the breaker's contacts separate and the current flowing through the circuit is interrupted. This can happen when the breaker is tripped or when a fault occurs in the circuit.
When the breaker's contacts separate, the current flowing through the circuit is suddenly interrupted, creating a high-voltage, high-current discharge between the contacts. This discharge is known as an arc.
The arc is a plasma, a hot, ionized gas that is created when the air or other gases in the breaker's contacts are heated to extremely high temperatures (typically in the range of 10,000 to 30,000 Kelvin) by the electrical discharge. The arc is characterized by its bright, glowing appearance and its ability to conduct electricity.
The arc is a critical component of the circuit breaker's operation, as it allows the breaker to interrupt the current flowing through the circuit without causing a significant voltage drop or a spark that could ignite nearby flammable materials. The arc is also responsible for the characteristic "crackling" or "popping" sound that is often heard when a circuit breaker trips.
There are several types of arcs that can occur in a circuit breaker, including:
- Air arc: This is the most common type of arc, which occurs when the breaker's contacts separate and the air in the breaker is ionized.
- Vacuum arc: This type of arc occurs when the breaker's contacts separate and the vacuum in the breaker is ionized.
- SF6 arc: This type of arc occurs when the breaker's contacts separate and the sulfur hexafluoride (SF6) gas in the breaker is ionized.
The characteristics of the arc, such as its duration, voltage, and current, can affect the performance and reliability of the circuit breaker.