Views: 0 Author: Site Editor Publish Time: 2022-07-26 Origin: Site
Miniature circuit breakers have the characteristics of advanced structure, reliable performance, strong breaking capacity, beautiful and compact appearance, etc. They are mainly used in places with AC 50HZ or 60HZ, rated voltage below 400V, and rated working current below 63A.
How many parts does a miniature circuit breaker consist of?
What are the design points of miniature circuit breakers?
What are the advantages of miniature circuit breaker?
The miniature circuit breaker consists of the following main parts:
1. Breakable contact connection. It consists of fixed contacts and movable contacts.
2. Devices consisting of metal cylinders or insulating cylinders, in which disconnectable contact connection and arc extinguishing equipment and transmissions are installed.
3. The transmission device that drives the contact.
4. Arc extinguishing equipment.
When the circuit breaker is commonly used, the moving contact of the miniature circuit breaker is separated from the fixed contact by a mechanical method. When closing, the moving contact and the fixed contact are closed by the opposite mechanical movement. During the operation of making and breaking the load circuit, arcing will be generated between the fixed contact and the moving contact. The arc generated during the opening process is much more severe than the closing process. When the breaking current is very large, especially when breaking a short circuit, the arc is very large, and it is often very difficult to disconnect the circuit.
1) The coordination of miniature circuit breakers should consider the instantaneous release action value of the upper circuit breaker, which should be greater than the maximum expected short-circuit current at the outlet end of the lower circuit breaker. If the difference in short-circuit current value is not large, the upper-level circuit breaker can choose a release with short delay.
2) When the short-circuit current is greater than or equal to the setting value of its instantaneous release, the miniature circuit breaker will trip within a few milliseconds, so the lower-level protection appliances should not use circuit breakers to achieve selective protection requirements.
3) For a miniature circuit breaker with short delay, when its time limit is set at the maximum delay, its on-off capacity will decrease. Therefore, in the selective protection circuit, consider that the short-time delay on-off capacity of the circuit breaker should meet the requirements.
When a fault occurs in the system, the protection of the faulty element acts and its circuit breaker fails to trip, and the protection of the faulty element acts on the adjacent circuit breaker of the substation to trip, and the conditional miniature circuit breaker can also use the channel to make the remote related the wiring in which the circuit breakers trip at the same time. It is called circuit breaker failure protection. Generally, after the phase current element is judged by phase separation operates, two sets of starting contacts are output, which are connected in series with the external action protection contacts to protect the starting failure when the line, bus tie or sectional circuit breaker fails.
For many years, Zhejiang Shilong Electric Technology Co., Ltd. has been a trustworthy supplier in the miniature circuit breaker area. Rich product categories and high-quality after-sales service are the reasons why they are popular with customers.
