乐清市东禾电气有限公司

Summary

KYN28A-12 indoor AC metal armored central switchgear. It is applicable to three-phase AC power system with rated voltage of 12kV and rated frequency of 50Hz. It is used to receive and distribute electric energy and control, protect and monitor the circuit.

Compliance with standards:

GB3906-2006 3.6 ~ 40.5kV AC metal enclosed switchgear and controlgear gb11022-89 general technical conditions for high voltage switchgear

IEC298 (1990) AC metal enclosed switchgear and control equipment with rated voltage above 1kV and below 50kV dl404-97 technical conditions for ordering indoor AC high voltage switchgear

Odel meaning

Functions and features

The switchgear is designed according to the armored metal enclosed switchgear in gb3906-91. The whole is composed of cabinet and middle mounted withdrawable parts (i.e. handcart) (see Figure). The cabinet is divided into four separate compartments. The protection grade of the enclosure is IP4X, and the grade of each compartment and circuit breaker room when the door is opened is IP2X. It has overhead incoming and outgoing lines, cable incoming and outgoing lines and other functional schemes, which form a complete set of power distribution system devices after arrangement and combination. The switchgear can be installed, debugged and maintained from the front, so it can be back-to-back, double arranged and installed against the wall, which improves the safety and flexibility of the switchgear and reduces the floor area.

◆ shell and others

The main cabinet frame of the switchgear is made of aluminum zinc coated steel sheet, processed by CNC machine tool and adopts multiple folding process, so that the whole cabinet not only has the advantages of high precision, strong corrosion resistance and oxidation resistance, but also has the advantages of light weight, high mechanical strength and beautiful appearance compared with other similar equipment due to the use of multiple folding process. The cabinet body adopts an assembled structure, which is connected by riveting nuts and high-strength bolts, so that the processing cycle is short, the parts are universal, the floor area is small, and it is easy to organize production.

◆ handcart

The handcart frame is assembled from thin steel plate processed by CNC machine tool. The handcart is insulated with the cabinet, and the mechanism interlocking is safe, reliable and flexible. According to the purpose, the handcart can be divided into circuit breaker handcart, voltage transformer handcart, metering handcart, isolation handcart, etc. All kinds of handcarts are changed according to module and building block type, and handcarts of the same specification can be exchanged 100% freely.

The handcart has disconnection position, test position and working position in the cabinet. Each position is equipped with positioning device to ensure reliable interlocking. It must be operated according to the interlocking anti misoperation procedure. All handcarts are pushed and exited by shaking nuts and screw rods. Its operation is light and flexible and suitable for the operation of personnel on duty. When the handcart needs to remove the cabinet, it can be easily pulled out with a special transfer car for various inspection and maintenance; Moreover, the central type is adopted, and the whole handcart has small volume and is very convenient for inspection and maintenance.

◆ compartment

The main electrical components of the switchgear have their own independent compartments, namely: circuit breaker handcart room, bus room, cable room and relay instrument room. The protection grade of each compartment shall reach IP2X; Except for the relay room, the other three compartments have their pressure relief channels respectively. Due to the central type, the space of the cable room is greatly increased, so the equipment can connect multiple cables.

a. Circuit breaker compartment

Rails are installed on both sides of the isolation for the handcart 15 to move and slide from the disconnected position and the test position to the working position in the cabinet. The diaphragm 13 (valve) of the static contact box 6 is installed behind the rear wall of the handcart chamber. When the handcart moves from the off position and test position to the working position, the valves on the upper and lower static contact boxes are linked with the handcart and open automatically at the same time; When moving in the opposite direction, the valve will close automatically until the handcart retreats to a certain position and covers the static contact box to form effective isolation. Since the upper and lower valves can be operated separately, the valve on the live side can be locked during maintenance, so as to ensure that the maintenance personnel do not touch the live body. When the circuit breaker room door is closed, the handcart can also be operated. Through the observation window of the middle door, the disposal, closing position and energy storage status of the handcart in the compartment can be observed.

b. Bus compartment

The main bus 4 is a single splicing and mutually penetrating connection. It is fixed through the branch bus 2 and the static contact box. The main bus and connecting bus are copper bars with rectangular section, which are assembled by two bus bars when used for high current load. The branch bus is connected to the static contact box 6 and the main bus through bolts without other support. For special needs, the bus can be covered with heat shrinkable sleeve, connecting bolt insulation sleeve and end cap, and the bus of adjacent cabinets can be fixed with sleeve 3. In this way, the air buffer reserved between the connecting buses can prevent it from melting in case of internal fault arc, and the bushing 3 can effectively limit the accident to this cabinet without spreading to other cabinets.

c. Cable compartment

The switchgear adopts the central type, so the space of the cable room is large. Current transformer 7 and grounding switch 8 are installed on the rear wall of the compartment, and lightning arrester 10 is installed on the lower part of the compartment. After opening the lower door of the cabinet, the construction personnel can enter the cabinet from below for installation and maintenance. The cable connecting conductor in the cable room can be connected with 1 ~ 3 single core cables per phase. When necessary, 6 single core cables can be connected in parallel, and slotted removable non-metallic sealing plates or non-magnetic metal sealing plates are prepared at the bottom of the cabinet connecting the cables to ensure convenient construction.

d. Relay instrument room

Relay protection elements, instruments, live monitoring indicators and special secondary equipment can be installed in the relay instrument room. The control line is laid in a trunking with sufficient space and has a metal cover plate to isolate the secondary line from the high voltage chamber. The left trunking is reserved for the introduction and introduction of control small bus. The control line inside the switch cabinet is laid on the right, and a small bus crossing hole for construction is reserved on the top plate of the relay instrument room. During wiring, the top cover plate of the instrument room can be turned over to facilitate the installation of small bus.

◆ prevent misoperation of interlocking device

The switch cabinet has reliable interlocking device to meet the requirements of "five prevention".

a. The door of the instrument room is equipped with a prompt button or KK type change-over switch to prevent false closing and opening of the circuit breaker

b. When the circuit breaker handcart is in the test or working position, the circuit breaker can be closed and opened. Moreover, after the circuit breaker is closed, the handcart cannot move, so as to prevent the circuit breaker from being pushed and erected by mistake with load.

c. only when the grounding switch is in the open position, the circuit breaker handcart can be moved from the open and test position to the working position. Only when the circuit breaker handcart is in the test and off position, the grounding switch can be closed (the grounding switch can be equipped with voltage display device), so as to prevent the live misclosing of the grounding switch and the closing of the circuit breaker when the grounding switch is in the closed position.

d. When the grounding switch is in the opening position, the lower door and rear door cannot be opened to prevent entering the live interval by mistake.

e. When the circuit breaker handcart is indeed in the test or working position and there is no control voltage, it can only be opened manually and cannot be closed.

f. When the circuit breaker handcart is in the working position, the secondary plug is locked and cannot be pulled out.

g. Each cabinet can be equipped with electrical interlocking.

The switchgear can also be equipped with an electromagnetic lock locking device on the operating mechanism of the grounding switch to improve reliability. Its order is selected according to the needs of users.

◆ pressure relief device

A pressure relief device is set above the circuit breaker handcart room, bus bar room and cable room. When an internal fault arc occurs in the circuit breaker or bus bar, the air pressure inside the switch cabinet increases with the occurrence of the arc, and the front is closed by a special sealing ring installed on the door. The pressure relief metal plate equipped on the top will be automatically opened to release pressure and discharge gas, so as to ensure the safety of operators and switchgear;

◆ the secondary plug is interlocked with the hand position

The connection between the secondary line of switchgear and the secondary line of circuit breaker handcart is realized through manual secondary aviation plug. The moving contact of the secondary plug is connected with the circuit breaker handcart through a nylon bellows, and the secondary static contact seat is installed at the upper right of the handcart room of the switch cabinet. Only when the circuit breaker handcart is in the test and off position can the secondary plug be inserted and released. When the circuit breaker handcart is in the working position, the secondary plug is locked and cannot be released due to mechanical interlocking.

◆ live display device

If required by the user, the switch cabinet can be equipped with an option to detect the operation of the primary circuit, i.e. live display device. The device consists of two units: high voltage sensor and display. The device can not only prompt the power on status of the high-voltage circuit, but also cooperate with the electromagnetic lock to realize the forced locking of the grounding switch handle and the network door, so as to prevent the grounding switch from being closed and entering the charged interval, so as to improve the error prevention performance of the supporting products.

◆ prevent condensation and corrosion

In order to prevent the danger caused by condensation in the climate environment with high humidity or large temperature change, heaters are installed in the circuit breaker room and cable room respectively, so as to use in the above environment and prevent corrosion.

◆ grounding device

There are 5 separate in the cable room × The 40mm grounding copper bar runs through the adjacent switchgear and is in good contact with the cabinet body. This grounding bar is used for directly grounded components. At the same time, because the whole cabinet is connected with aluminum-zinc coated plate, the whole cabinet is in a good grounding state to ensure the safety of operators touching the cabinet.

Main technical parameters of vacuum circuit breaker

Normal service conditions

◇ ambient air temperature: maximum temperature + 40 ℃. Minimum temperature - 15 ℃.

◇ relative humidity: daily average relative humidity: ≤ 95%; The daily average water vapor pressure shall not exceed 2.2kpa; Monthly average relative humidity: ≤ 90%; The monthly average water vapor force shall not exceed 1.8kpa;

◇ altitude: below 1000m. ◇ seismic intensity: no more than 8 degrees.

◇ the surrounding air shall not be obviously polluted by corrosive or combustible gas, water vapor, etc.

◇ places without violent vibration.

◇ when it is used under normal conditions beyond those specified in GB3906, it shall be negotiated between the user and the company.

Outline dimension drawing of switch cabinet

A handcart

The handcart frame is made of thin steel plate processed by CNC machine tool and riveted and welded. According to the purpose, the handcart can be divided into circuit breaker handcart, voltage transformer handcart, isolation handcart, metering handcart, etc. handcarts of the same specification can be easily interchanged. The handcart has isolation position, test position and working position in the cabinet, and each position is equipped with positioning device to ensure that the handcart cannot move freely when it is in the above position, and the interlocking must be released when it is moved.

B bus room

The bus is led from one switchgear to another and fixed through branch bus and static contact box. The flat branch bus is bolted to the static contact box and the main bus without any other clamp or insulator connection. When the user and the project have special needs, the connecting bolts on the bus bar can be encapsulated with insulation and end caps. When the bus passes through the partition of the switch cabinet, it shall be fixed with bus bushing. In case of internal fault arc, it can limit the spread of accident to adjacent cabinets and ensure the mechanical strength of bus.

C) cable room

Current transformer, grounding switch, lightning arrester and cable can be installed in the cable room, and slotted detachable aluminum plate can be prepared at the bottom to ensure convenient construction on site.

Outline dimension drawing of switch cabinet

D relay meter room

The relay instrument room is used to install various relays, instruments, signal indicators, operating switches and other components. In addition, according to the user's requirements, a small bus room can be added at the top of the instrument room, and sixteen control small buses can be laid.

Pressure relief device

A pressure relief device is set above the handcart room, bus room and cable room. When an internal fault arc occurs in the circuit breaker or main bus and cable room, with the occurrence of the arc, the internal air pressure in the switchgear rises to a certain pressure. After reaching a certain pressure, the pressure relief metal plate of the top device will be automatically opened to release pressure and exhaust gas, so as to ensure the safety of operators and switchgear.

Latch structure

The connection between the middle door and the cabinet body adopts the latch structure and is equipped with a lifting mechanism, which makes it more convenient to open the middle door. When the middle door is closed, its connection strength with the cabinet body is better, which enhances the ability to effectively resist internal arcing faults.