Important considerations in choosing the right vacuum circuit breaker for your equipment
In the power system, the vacuum circuit breaker is an important role, it can not only distribute electricity, but also start asynchronous motors, protection of power lines and motors. Once a serious overload, short-circuit or under-voltage faults, it will automatically cut off the circuit, it is simply the power system "little guardian". Today, we will talk about how to choose the right vacuum circuit breaker.
In order to ensure the safety of high-voltage appliances in normal operation, maintenance, short-circuit and over-voltage, the following conditions have to be considered when selecting:
1.Normal operating conditions: including voltage, current, frequency and mechanical load. For example, you have to make sure that the rated voltage and current of the circuit breaker can match the demand of your circuit.
2.Short-circuit conditions: including short-term withstand current, peak withstand current, and closing and breaking current. These parameters directly affect the performance of the circuit breaker during a short circuit.
3.Environmental conditions: temperature, humidity, altitude, earthquakes, etc. all affect the performance of the circuit breaker. For example, in a high temperature or high humidity environment, the selection of circuit breakers requires special attention.
4.Voltage resistance: This includes the level of insulation. The higher the insulation level, the safer the equipment.1. Rated opening distance: This refers to the distance between the dynamic and static contacts of the vacuum circuit breaker in the opening state. It is related to the rated voltage, service conditions, the nature of the breaking current, the contact material and the compressive strength of the vacuum gap. The choice of rated opening has significant influence on insulation performance.
5. Contact stroke: This parameter ensures that the contact can maintain a certain pressure after wear, and obtain a certain initial kinetic energy at the opening of the switch to improve the initial opening speed of the switch and the speed of medium recovery.
6. Contact working pressure: The working pressure has an important impact on the performance of the vacuum circuit breaker, and should meet the contact resistance, dynamic stability test requirements, inhibition of closing bounce and reduce the requirements of opening spring vibration.
7. Opening speed and closing speed: opening speed affects the speed of dielectric strength recovery between contacts after the current crossing zero, while closing speed affects the electrical wear and closing impact of contacts during the closing process.
8. Contact closing bounce time: The bounce time is an important sign to measure the performance of the vacuum circuit breaker, which is related to the contact bouncing pressure, closing speed, opening distance and contact material.
9. Tripolar homogeneity : indicates the degree of simultaneous closure or separation of the three extreme, affecting the breaking ability of the switch.
10. Coaxiality of dynamic and static contacts: coaxiality has specific requirements for vacuum switch tubes, which affects the installation of switch tubes and the type of operating mechanism.
11. Rated current and breaking capacity: Select the appropriate rated current and breaking capacity according to the maximum short-circuit current and transformer capacity of the system.
12. Environmental and safety requirements: Consider the special requirements of the use of the environment (such as chemical plants, military facilities), such as fire safety characteristics, environmental characteristics, etc.
13.Operating mechanism: Select the appropriate operating mechanism according to the frequency of operation and the reliability of the operating mechanism, such as electric spring operating mechanism or permanent magnet operating mechanism.
Vacuum circuit breaker working properly :
In order for the vacuum circuit breaker to work properly, you have to choose the rated voltage of the high voltage electrical equipment based on the operating voltage to ensure that it meets the nominal system voltage of the circuit in which it is located. Also, the rated current should not be less than the continuous operating current of the circuit.
Shaanxi West Power Tongzhong Electrical Co., Ltd. produces ,JN15-12 Indoor Grounding Switch ,which is a product with advanced level developed based on the latest technology of grounding switch at home and abroad. It is applicable to AC power systems of 12kV and below, and can be used with various standard high-voltage switchgear as grounding protection.
JN15-12 Indoor Grounding Switch has many advantages:
1. Smaller product size, matching with a variety of phase spacing;
2. Simple and compact structure, light weight;
3. Flexible operation and easy installation;
4. Good dynamic and thermal stability, which can be stabilized up to 4s;
5. Closing speed and splitting speed are independent of human operation;
6. Standard structure for manual operation, can also be equipped with electric operation mode.
