Our commonly used 24/40.5kV switchgear contact boxes and through-wall bushings basically use internal and external shielding forms, i.e. capacitive voltage divider bus bushings, which are bus bushings made by utilizing the principle of capacitive equipotential shielding and voltage divider to effectively reduce the size of the bushings and withstand higher lightning impulse withstand voltages and industrial frequency withstand voltages. Sleeving or similar structures are used in medium voltage switchgear to transport conductors from one side of the grounding barrier to the other. Typical uses are roof entrance bushings, which are used to carry conductors from the outside of the switchgear […]

Gas-filled cabinet C-GIS is the abbreviation of gas-insulated switchgear, which is defined according to the form of main switch insulation, corresponding to air-insulated switchgear and solid-insulated switchgear. That is, the switchgear of the switchgear cabinet, circuit breakers and connections and other main circuits are sealed inside the gas box filled with insulating gas, the external main busbar, cable connections, etc. using solid insulation, the current transformer is mounted directly on the outlet casing or cable using a penetrating type, but also epoxy strut-type current transformers are mounted inside the gas box, and the terminals are reserved on the outside of […]

The IEEE standard is a standard developed by the American Institute of Electrical and Electronics Engineers to ensure the correct operation and interoperability of electrical equipment, to promote interconnectivity between different devices, and to improve the reliability and safety of equipment, and it is widely used in North America and other regions. According to statistics, 78% of the world adopts IEC standards, 8% adopts IEEE standards, and 9% adopts GOST (Russian Standard) standards. The countries adopting China GB standard account for 1%, and the remaining 4% of the countries are adopting a mixture of standards. IEEE standards usually include two […]

The current switches commonly used in switchgear are generally categorized as: Disconnect Switches Isolation that is to separate the two parts to achieve the safety requirements, electrical isolation to achieve the two parts of the circuit to achieve a safe electrical gap, even if there are different voltages on both sides, but also do not interfere with each other, their own safe operation, dual power feed to the isolation cabinet to achieve the two sections of the bus respective operation. Isolation switches also require visible breaks, appliances suitable for isolation in the disconnected position must have an isolation distance that […]

The busbar load capacity is a complex issue, which is a systematic project that needs to be considered within the switchgear system, designed to include cabinet dimensions, cabinet ventilation, and other factors. There are several formulas for calculating current-carrying capacity, all of which are based on the balance between heat generation and heat dissipation. The formula for calculating the amount of current carrying capacity in the air of a single copper row: Where I is the rated current. R is the resistance value of the copper row, the width of the copper row b, height is a. A is the […]

Transformers are always rated in kVA and not kW As the name suggests, a transformer only transfers power from one circuit to another without changing the values of power and frequency. In other words, it can only raise or lower the values of current and voltage while keeping power and frequency constant. General data is printed on the transformer nameplate for more detailed information. Examples include VA rating, single phase/three phase (power or distribution transformer), step-up/step-down, connections, etc. In simple terms, transformers have two types of losses; 1. copper loss 2. iron or ferrous losses or insulation losses Copper loss […]

Regarding KYN28A center-mounted cabinet and ring network cabinet, these are two concepts. Both of them are switchgear, and switchgear can be categorized according to application, insulation method, structure type and so on. KYN28A center-mounted cabinet is based on the product structure, center-mounted cabinet is an air-insulated metal-enclosed withdrawable circuit breaker switchgear, is relative to the floor-standing (Floor Standing) circuit breaker switchgear, floor-standing circuit breaker trolley on the ground to move, directly inserted into the interior of the switchgear, advancing or swinging into the working position. Center-standing cabinet structure is compact, make full use of space, circuit breaker trolley in the […]

1. Introduction With the domestic products going out and the construction of the Belt and Road, more and more Chinese switchgear are also actively participating in the competition of the international market, however, due to the lack of understanding and experience of foreign demand, only some large enterprises can really go out and expand their market share. Firstly, the product standards and parameters should meet the requirements of customers, and secondly, foreign customers have higher requirements for product safety. It is necessary to understand the demand comprehensively to be able to stand firm in the market and go out. 2. […]

Internal arc fault test IAC AFLR 31.5kA/1s, 40kA/1s, and even 50kA/1s, although the risk of arc test is high, there are very many uncertainties, but not through any “special treatment”, through the test is not impossible to pass, the key is that the design of the product must be in full accordance with the internal arc requirements, fine-tuning every detail of the production of quality and quantity, you can ensure that each switchgear can pass the test without worrying about any random inspection. The key is that the product design must be completely in accordance with the requirements of the […]

These two days EP exhibition, Schneider, ABB coincidentally show the medium voltage Tubular Busbar Switchgear. 12kV and 40.5kV air insulated switchgear. Abstract: With the development of carbon peak, carbon neutral, the green, energy-saving medium-voltage switchgear has become the trend of development, in which the use of materials can be saved, reduce non-ferrous metals, etc., the comprehensive benefits are significant; 1 Introduction The busbar, also known as the busbar, in the switchgear carries an important role in the conduction of current, while bearing the short-circuit current generated if a short-circuit fault occurs in the distribution system, the busbar current on the […]