Vacuum circuit breakers utilize a unique method to extinguish electrical arcs by separating contacts in a vacuum. This process takes advantage of the vacuum's inherent high insulation properties to quickly quench the arc. When the electrical current reaches zero, the arc naturally dissipates, reinstating the insulation barrier and effectively preventing the re-ignition of the arc. This efficient mechanism is key to their high reliability and performance in managing high-voltage circuits.

1.The performance and applicability of vacuum circuit breakers are mainly defined by the following key technical parameters:
Rated Voltage: The maximum voltage level the breaker can handle safely, typically in kilovolts (kV).

2.Rated Current: The highest current the breaker can carry continuously under standard conditions, usually in amperes (A).

3.Breaking Capacity: Also known as interrupting capacity, it's the maximum fault current the breaker can interrupt safely, measured in kiloamperes (kA). This parameter is vital for evaluating the breaker's capability.

4.Mechanical Life: The number of operations the breaker can perform without significant maintenance.

5.Electrical Life: The number of operational cycles (open and close) the breaker can achieve under defined conditions.

6.Insulation Level: Involves phase-to-ground and phase-to-phase insulation strength, typically assessed through dielectric tests, to ensure operational safety in high-voltage scenarios.

7.Operation Time: The duration from activating the breaker to fully disconnecting the circuit, crucial for the system's protection and stability.

8.Reclosing Time: The time gap between the breaker's opening and subsequent reclosing, significant for systems with automatic reclosing mechanisms.

Selecting the right vacuum circuit breaker for your power system involves careful consideration of several key factors. Begin with the system's voltage level to ensure compatibility with the breaker's rated voltage. Next, assess the system's maximum load current to choose a breaker that can handle this capacity. The breaker's breaking capacity is also crucial; it must be capable of safely interrupting the system's potential maximum short-circuit current. Additionally, take into account the frequency of operation to determine the necessary mechanical and electrical life for long-term reliability. Choose an operational mode (manual, electric, or remote) and installation type (fixed or withdrawable) that best suits your application. Environmental conditions such as temperature, humidity, and altitude also play a significant role in ensuring the breaker's operational stability. Opt for products that meet both international and regional standards. Lastly, evaluate the supplier's technical support, product quality, and cost-effectiveness to find the vacuum circuit breaker that best meets the needs of your power system.

The upkeep and scrutiny of vacuum circuit breakers predominantly revolve around maintaining cleanliness inside and outside the breaker, verifying that the mechanical operations are functioning correctly, periodically assessing the vacuum level within the vacuum chamber, and examining and upholding the control system. Given the unique nature of vacuum circuit breakers, the vacuum chamber, once sealed, is inaccessible for user inspection. Consequently, the evaluation of the vacuum chamber relies on indirect methods such as insulation resistance measurements and the observation of arc extinguishing during breaker operation.