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KYN28A-12 Kai-mounted removable metal-enclosed switchgear

Category: Medium Voltage Switchgear

Description: It mainly produces all kinds of high, medium and low voltage switchgear. Since its establishment, it has developed rapidly with the support of the majority of users. At present, it has a number of advanced machinery and equipment production lines and a scientific research and management team composed of middle and senior talents with rich experience and strong technical force. Technological level and product quality, to better serve our customers.

Keywords: high-voltage switchgear, medium-voltage switchgear, low-voltage switchgear, box-type substation, integrated distribution station

Product Details


KYN28A-1 2 armored removable metal-enclosed switchgear (referred to as switchgear) is a new product designed and developed by Hefei Liyuan Power Equipment Co., Ltd. on the basis of foreign advanced design and manufacturing technology. It can replace various old products. Type armored metal-enclosed switchgear, its products have the following obvious advantages: the shell of the product is completely made of aluminum-zinc sheets processed by CNC machine tools and assembled with bolts, which has high mechanical strength, effectively guaranteeing The neatness and beauty of the product. The cabinet door is coated with plastic spray, which has strong resistance to impact and corrosion. The product shell has a Confucian 4X level of protection.

The main switch of this product can be equipped with 3AH of S Renmens, VD4 vacuum circuit breaker of ABB, C3 series fixed load switch, and various domestic series vacuum circuit breakers (such as VSl, ZNl2) Wait.

No matter what kind of circuit breaker is selected, its circuit breaker has the unique advantages of long life, high parameters, less maintenance and small size.

KYN28A-12 armored center-mounted metal-enclosed switchgear is suitable for 3.6-12kV three-phase AC 50Hz power grid, which is used for receiving and distributing power, and for controlling, monitoring and protecting circuits. Can be used for single busbar sectional system and double busbar sectional system. The switchgear meets the requirements of GB3906 "3-35kV AC Metal-enclosed Switchgear" and DL404 "Technical Conditions for Ordering Indoor AC High Voltage Switchgear", and has a complete and reliable "five-proof" locking function.

Model Description


KYN28A-12 Kai-mounted removable metal-enclosed switchgear


Use ambient conditions

Normal use conditions:

Ambient temperature: the highest temperature is +40°C, the lowest temperature is -15°C, and the average temperature within 24 hours is not higher than +35°C.

Ambient humidity: The daily average relative humidity is 95% and below, and the monthly average relative humidity is 90% and below.

The maximum altitude does not exceed 1000m.

The earthquake intensity should not exceed 8 degrees.

No fire, no explosion hazard, no serious pollution, no chemical corrosive gas and violent vibration. Special Conditions of Use:

When the switchgear is installed in an area with an altitude greater than 1000mm, you must negotiate with the manufacturer to take necessary strong insulation measures when ordering.

When the maximum ambient temperature exceeds +40°C, the rated current carrying capacity of the switchgear will be reduced by a certain factor, which must be confirmed by the manufacturer when ordering.

Special Note:

In many areas of China, the humidity is high, and the temperature fluctuates rapidly and greatly. The switchgear operates in this climate environment, and there is a danger of condensation. Therefore, when the switchgear is in standby and running state, the user should The heater is guaranteed to be put into operation all day long, but the heater may not be put into operation when the switchgear with a load current above 1250A is in operation.

Main technical parameters of switchgear


KYN28A-12 KYN28A-12 Removable Metal Enclosed Switchgear


Introduction to the main components of the primary circuit

The main electrical components of the primary circuit selected in the switchgear are for reference when selecting models. For more detailed instructions, please refer to the relevant product manuals.

The vacuum circuit breaker is the most important electrical component in the primary circuit of the switchgear. The main types are VD4 vacuum circuit breaker produced by ABB company, 3AH vacuum circuit breaker produced by SIEMENS company, and VS1 vacuum circuit breaker produced by Senyuan company. Circuit breaker, etc., here is only a brief description of VD4 vacuum circuit breaker. VD4 vacuum circuit breaker VD4 vacuum circuit breaker is the most important electrical component in the primary circuit of the switchgear (see Figure 1). It is provided by ABB Group and fully meets the requirements of international and national standards.

The VD4 vacuum circuit breaker can operate frequently and break short-circuit current many times within the working current range. Mechanical life can be up to 30,000 times, full capacity short-circuit current breaking times can be up to 100 times. It is suitable for reclosing operation and has extremely high operational reliability. Under normal working conditions, the circuit breaker is used within the allowable technical parameters to ensure safe and reliable operation. During use, the VD4 vacuum circuit breaker only needs a small amount of maintenance work such as cleaning and lubrication.

When the circuit breaker is used to control the 3.6-12kV motor, if the starting current is less than 600A and the starting is frequent, it is recommended to install a zinc oxide arrester to limit the operating overvoltage. The specific requirements shall be determined by the user and the manufacturer when ordering Negotiated.

The operating mechanism matched with the VD4 vacuum circuit breaker is a flat coil spring operating mechanism with compact structure and stable performance. The operating mechanism operates the three-phase arc extinguishing chamber at the same time. The scroll spring can be equipped with both manual and electric energy storage methods. The operating mechanism is suitable for automatic reclosing operation.

The basic configuration mode of the operating mechanism can meet the requirements of most users, and it has complete and reliable electrical and mechanical auxiliary components. The VD4 vacuum circuit breaker trolley can be operated electrically.

For specific technical parameters, please refer to the relevant product manual.

Load Switch

The main types of load switches are NAL12 load switch and NALF12 load switch-fuse combination, FN12-12 D/630-20 AC high voltage load switch, FN12-12(R)D/100-31.5 type AC high voltage load switch - fuse combination appliances, etc.

The load switch should be reasonable in design, simple in structure, convenient in operation and stable in performance. It is suitable for a wide range of medium voltage switchgear, and can be used in transformers, capacitors, cables, overhead lines, feeders and ring network systems.

The load switch can operate when the door of the switch cabinet is closed, and the load switch and grounding switch have reliable mechanical locking.

Under normal working conditions, the load switch can operate for a long time under the rated parameters and only needs a small amount of maintenance.


KYN28A-12 Kai-mounted removable metal-enclosed switchgear


Gapless Zinc Oxide Surge Arrester

The main types of arresters in the switchgear are MWD non-gap zinc oxide arresters produced by ABB and domestic HY5WS arresters

Earthing switch

The main types of earthing switches are the EK6 type earthing switch produced by ABB and the domestic JN15 type earthing switch. The earthing switch has auxiliary contacts, which provide signals of the opening and closing status of the earthing switch.

Current/Voltage Transformers

With the application and development of digital technology in measurement and protection, the requirements for measuring components in medium voltage systems have also changed. Compared with traditional measuring elements, today's measuring elements only need small electrical signals to meet the requirements. The technical parameters of the current/voltage transformer are shown in the following table:


KYN28A-12 Kai-mounted removable metal-enclosed switchgear



KYN28A-12 Removable Metal Enclosed Switchgear


Introduction to the main components of the secondary circuit

Protection Relay

User-specified protection relays can be configured according to user requirements.

Measuring instrument

The configuration of the measuring instrument is mainly based on the user's requirements and meets the requirements of the international standard measuring instrument guidelines. The company is mainly equipped with components from domestic advanced manufacturers, and can also be equipped with domestic instruments designated by users according to the requirements of users.

Other secondary components

The protection of the operating power supply of the switch cabinet adopts a miniature air switch or a fuse.

The secondary terminal blocks of the switch cabinet are all phoenix terminals.

Auxiliary switches and secondary plug-ins of the switchgear are made of well-known company products with simple structure, excellent performance and reliable operation.

Switchgear structure


The switch cabinet consists of two parts: a fixed cabinet body and a removable part (referred to as a handcart). According to the function of the electrical equipment in the cabinet, the cabinet is divided into four different functional units with partitions. As shown in Figure 2, the busbar room A, circuit breaker room B, cable room C, and low-voltage room D. The outer shell of the cabinet and the partitions between the functional units are all made of aluminum-zinc-coated steel plates after bending and bolting.


KYN28A-12 Removable Metal Enclosed Switchgear


The removable parts of the switch cabinet can be equipped with VD4, VS1, 3AH and other vacuum circuit breaker handcarts, current transformer handcarts, voltage transformer handcarts, isolation handcarts, etc.

A live display device (selected by the user) to detect the operation of the primary circuit can be installed in the switch cabinet. The device consists of a high-voltage sensor and a display. The sensor is installed on the feeder side, and the display is installed on the low-voltage room panel of the switch cabinet.

The protection level of the switchgear enclosure is IP4X, and the protection level of the circuit breaker door when it is opened is IP2X.

The switchgear considers the influence of arc fault inside the switchgear from the structure, and according to the PEHLA regulations No. 4 Sections 1-3 and 6 and IEC60298 Section 6.108, GB3906 Section 7.15, VDE0670 Section 601 Strict arc ignition test is carried out according to the regulations, which can effectively ensure the safety of operators and equipment.

Since the installation and debugging of the switch cabinet are carried out on the front, the switch cabinet can be installed on the wall to save the floor space. However, if conditions permit, it is still recommended to leave a certain installation and maintenance channel between the back of the switch cabinet and the partition wall , the width is about 800mm.


KYN28A-12 Removable Metal Enclosed Switchgear


Housing, bulkhead and pressure relief

The shell and clapboard of the switchgear are assembled and bolted on a special fixture after machining and bending of the aluminum-zinc plate coated by the educational affairs with the CNC machine tool. Therefore, the assembled switchgear can ensure the uniformity of size and the High mechanical strength.

The door panel paint of the switch cabinet is baked after electrostatic spraying, and the surface is impact-resistant, corrosion-resistant and ensures a beautiful appearance.

The top of the switchgear is equipped with pressure relief devices above the circuit breaker room, busbar room and cable room. When an internal fault arc occurs, with the appearance of the arc, the air pressure inside the switchgear will increase, and the pressure installed on the top will increase. The release metal plate will be automatically opened to release the pressure and exhaust gas, and the special sealing ring installed on the door closes the front of the cabinet to ensure the safety of the operator and the switchgear.

Circuit Breaker Room

A handcart guide rail is installed in the circuit breaker compartment (Fig. 3) for the handcart to travel electrically or manually in the compartment. The handcart can be moved between the "work" position and the "test/isolation" position. The valve is made of metal plate by spraying and is installed on the rear wall of the handcart room. When the handcart moves from the "test/isolation" position to the "work" position, the valve is automatically opened, and the valve is automatically closed when the handcart moves in the opposite direction, so as to ensure that the operator will not touch the charged body.


KYN28A-12 KYN28A-12 Removable Metal Enclosed Switchgear


The handcart can be operated when the door of the switch cabinet is closed. Through the observation window, you can see the position of the handcart in the cabinet, and you can also see the ON/O F F button and the circuit breaker on the circuit breaker handcart. Mechanical position indicator, and spring charge/discharge status indicator.

The connection between the secondary line on the switch cabinet and the secondary line of the handcart is realized through the manual secondary plug. The moving contact of the secondary plug is connected to the handcart through a nylon bellows. The secondary socket is installed at the upper right of the circuit breaker room of the switchgear. Only when the handcart is in the "test/isolation" position, can the Plug and unplug the secondary plug. When the handcart is in the "working" position, the secondary plug is locked and cannot be removed due to the mechanical interlocking effect. The circuit breaker handcart can only be manually opened before the secondary plug is connected, but because the closing and blocking electromagnet of the circuit breaker handcart is not energized, it cannot be manually closed. handcart

The frame of the handcart is made of cold rolled steel sheet by bending and welding. According to the purpose, the handcarts arranged in the circuit breaker room can be divided into V D 4, V S 1, 3 A H vacuum circuit breaker handcarts, V C fuse-vacuum contactor handcarts, current transformer handcarts, voltage transformer handcarts, Isolate handcarts, etc. All types of handcarts have the same height and depth, and handcarts of the same specification can be interchanged.

According to needs, the voltage transformer handcart can also be configured in the cable room.

The circuit breaker handcart has a "work" position and a "test/isolation" position in the cabinet, and each position is equipped with a positioning locking device to ensure that the handcart is only allowed to operate when it is in a specific position.

The mobile handcart must meet the interlocking conditions, and the circuit breaker must be disconnected before the handcart is moved.

When the circuit breaker handcart is pushed into the switch cabinet from the service trolley, it is first in the "test/isolation" position, and then the handcart is moved into the "work" position by the crank handle or electric operating mechanism.


KYN28A-12 Removable Metal Enclosed Switchgear


Low Pressure Chamber

The panel and room of the low-voltage room (Figure 5) can be equipped with relay protection components, instruments, live displays, analog bus bars, operation switches and secondary equipment with special requirements.

The standard grid board is used to install secondary equipment indoors, which can flexibly arrange various secondary components and facilitate wiring.

Control cables and secondary wires are laid in wire troughs with sufficient space on both sides, and have metal cover plates. The left wire trough is reserved for the control cable connected to the outside of the cabinet, and the secondary wire inside the switch cabinet is laid in the right wire trough. There are also small busbar passing holes on the side plate of the low-voltage room, which is convenient for on-site installation.

Prevent misoperation and interlock device

Mechanical locking function

The switchgear has a reliable interlocking device to ensure the personal safety of operators and equipment safety, and meets the requirements of SD 318 "Technical Conditions for High Voltage Switchgear Locking Devices". When the grounding switch and circuit breaker are in the off position, the handcart can move from the "test/isolation" position to the "work" position: and when the grounding switch is in the closed position, the handcart cannot move from the "test/ Quarantine”location moved to “work”location:

The earthing switch will only operate when the trolley is in the “test/isolated” or removed position:

The circuit breaker can only be closed when the circuit breaker trolley is properly in the "Test/Isolation" position or the "Work" position:


KYN28A-12 Kai-mounted removable metal-enclosed switchgear


Main circuit scheme


KYN28A-12 Removable Metal Enclosed Switchgear



KYN28A-12 Kai-mounted removable metal-enclosed switchgear



KYN28A-12 Kai-mounted removable metal-enclosed switchgear



KYN28A-12 Removable Metal Enclosed Switchgear



KYN28A-12 Kai-mounted removable metal-enclosed switchgear



KYN28A-12 Kai-mounted removable metal-enclosed switchgear



KYN28A-12 Kai-mounted removable metal-enclosed switchgear


Scheme application example


KYN28A-12 Kai-mounted removable metal-enclosed switchgear


Switchgear Layout

Since the installation, commissioning and operation of the switchgear are carried out at the front, the switchgear can be installed against the wall to save floor space. However, if conditions permit, it is still recommended to leave appropriate longitudinal passages between the rear cover of the switchgear and the wall and between the two sides of the switchgear and the wall. Figure 6 shows the reference plan for the layout of the power distribution room. This layout can be referred to regardless of whether the power distribution room is installed in the cable trench, installed under the cable layer, or installed on the cable. Figure 6 shows that the switchgear is arranged in a single row. If the switches are arranged in two rows face to face, the distance between the two rows of switchgear is not less than 2300mm.


KYN28A-12 Removable Metal Enclosed Switchgear


Switchgear foundation buried

The construction of the switchgear foundation shall comply with the provisions of the relevant clauses in the technical specifications for electric power construction, construction and acceptance.

No matter which way of incoming and outgoing lines is adopted, it is recommended to use a pre-processed frame base for the foundation of the switchgear.

As shown in Figure 7, the foundation frame of the switchgear generally requires the method of secondary watering. After the civil construction is completed, the electrical installation unit will bury the foundation frame. Drawings are made.

If the power distribution room is placed upstairs, please refer to Figure 8 for installation.


KYN28A-12 Kai-mounted removable metal-enclosed switchgear



KYN28A-12 Kai-mounted removable metal-enclosed switchgear


The foundation elevation of the timing switchgear for civil construction should consider the reserved height of the channel steel of the foundation frame, with a slight allowance, as shown in Figure 9, and pre-embed and anchor the switchgear at intervals of 1 to 1.5m along the longitudinal direction of the frame on the foundation of the switchgear steel plate. Figure 9 is a schematic diagram of the processing dimensions of three basic frames with different cabinet widths of 1000, 800, and 650 mm.

The basic frame is composed of welded channel steel and angle steel. The basic size requirements of the frame and the layout of the cable channel are shown in Figure 10. There is no strict requirement for the height of the channel steel, and C5 or C8 channel steel can be selected. The extension distance of the basic frame channel steel should be consistent with the size of the switchgear body frame, and its value is 1175 (1375) mm. The total length of the frame is determined according to the layout of the switchgear and the number of switchgears in each row.

The horizontal calibration should be carried out when the foundation frame is pre-buried. The horizontal error and straightness should not exceed 1mm per meter, the total error should not exceed 2mm, and the top surface of the foundation frame should be higher than the final floor of the power distribution room by about 3 to 5mm. The foundation should preferably be terrazzo. If it is cement, the cement label should not be lower than 500#.

The depth of the cable trench should be determined according to the type of cable and the requirements of the regulations.


KYN28A-12 Removable Metal Enclosed Switchgear


Switchgear Installation

Armored metal-enclosed switchgear should be installed in a dry, clean, and air-ventilated power distribution room. During installation, it is required that the basic frame and indoor floor of the switch cabinet in the power distribution room have been completed and accepted, and the door and window decoration and indoor lighting and ventilation projects in the power distribution room should be basically completed.

Use hooks or sticks to move the switchgear to the foundation in place, then screw down the foot adjustment screws to make it support the entire switchgear, then remove the sticks to reset the foot adjustment screws and adjust each To determine the verticality of the cabinets, arrange them neatly according to the arrangement diagram and screw on the cabinet screws to fix the entire arrangement.

Ordering Instructions

1. Provide the main wiring plan number, purpose and single-line system diagram, rated voltage, rated current, rated short-circuit breaking current, distribution room floor plan and switchgear arrangement diagram, etc.

2. Indicate the specifications of incoming/outgoing cables;

3. Requirements for switchgear control, measurement and protection functions, as well as requirements for other locking and automatic devices.

4. Models, specifications and quantities of main electrical components in the switchgear:

5. If bus bridge connection is required between switch cabinets or incoming cabinets, specific requirements data such as the rated current carrying capacity of the bus bridge, the span of the bus bridge, and the height from the ground should be provided;

6. When the switchgear is used in special environmental conditions, please specify in detail when ordering:

7. When other or more accessories and spare parts are needed, the type and quantity should be proposed.