◎Overview

Scope and main use

KYN28-24 armored removable AC metal-enclosed switchgear (hereinafter referred to as switchgear), suitable for indoor three-phase 50Hz rated voltage 24kV power system, mainly used in power plants, substations, industrial and mining enterprises and high-rise buildings In order to receive and distribute electrical energy and implement control protection and monitoring of the circuit.

KYN28-24 type switchgear can be equipped with domestic or imported high voltage AC vacuum circuit breakers.

Product reference standard

GB1984 high voltage AC circuit breaker.

GB3906 3-35kV AC metal-enclosed switchgear.

GBT11022 Common technical requirements for high voltage switchgear and control equipment standards

OLT404 indoor AC high voltage switchgear ordering technical conditions.

Technical guidelines for shared ordering of OLT593 high voltage switchgear

Environmental conditions

Normal use condition

Ambient temperature: maximum temperature: +40 ° C minimum temperature: -15 ° C, and the average value measured within 24 h does not exceed 35 ° C

Humidity conditions are as follows

- the average value of daily relative humidity does not exceed 95%; the average monthly relative humidity does not exceed 90%;

- the average value of the daily water vapor pressure does not exceed 22 kPa; the average monthly water vapor pressure does not exceed 18 kPa;

Condensation occasionally occurs under such conditions;

The altitude does not exceed 1000m;

The surrounding air is not significantly contaminated by dust, corrosive and flammable gases, vapours or salt sprays;

Vibration or ground motion from outside the switchgear and control equipment is negligible

The magnitude of the electromagnetic interference induced in the secondary system does not exceed 1.6 kV.

Special use conditions

When used under normal environmental conditions as specified in GB/T11022, the company and the user may negotiate and agree on special operating conditions beyond normal operating conditions.

In order to prevent condensation, the switchgear is equipped with a heater, which should be put into use when the switchgear is in standby mode. Pay attention to the operation of the heater when the switchgear is operating normally.

 

◎Technical parameters

 

◎Structure and working principle

Structure brief

The KYN28-24 switchgear consists of two parts: the cabinet and the removable parts (commonly known as the handcart). The cabinet is divided into multiple functional compartments by metal partitions, such as busbar compartment, circuit breaker compartment, cable compartment and relay instrumentation compartment.

The removable parts of the switchgear can be equipped with a vacuum circuit breaker handcart, a voltage transformer handcart, a lightning arrester handcart, an isolated handcart and a fuse handcart.

 

 

Main structural features

The switchgear can be double-arranged or back-to-back, which improves the safety and flexibility of the switchgear and reduces the floor space.

 

Shell

The outer casing of the switchgear is made of imported aluminum-zinc steel plate, which is processed by CNC machine tool and is made by multiple hemming process. The whole cabinet has high precision and strong anti-corrosion and anti-oxidation performance, and due to the multiple hemming process, the cabinet body is lighter in weight, higher in mechanical strength and beautiful in appearance than other similar equipment cabinets. The cabinet body adopts the armored structure and is connected by the rivet nut and the high-strength bolt, which shortens the processing cycle, has strong versatility of parts, and has less floor space, which is convenient for tissue production.

 

Handcart

The handcart skeleton is assembled by processing the thin steel plate through a CNC machine tool. The handcart and the cabinet have high precision and the mechanical interlock is reliable and flexible. According to the use, the handcart can be divided into circuit breaker handcart, voltage transformer handcart, metering handcart, and isolated handcart. The hand truck of the same specification can be freely interchanged. The handcart has a disconnection, test position and working position in the cabinet, and each position has a positioning device to ensure reliable interlocking. All kinds of hand trucks are driven and withdrawn by screw rods. The operation is light and flexible, suitable for the operation of the on-duty personnel. When the handcart needs to be removed from the cabinet, it can be easily removed with a dedicated transfer vehicle for various inspections and maintenance.

When the hand truck is transported into the cabinet circuit breaker room, it can be reliably locked in the disconnect/test position, and the cabinet position indicator shows its position. Only when the handcart is fully locked can the screw advancement mechanism be shaken and the handcart pushed to the working position. When the handcart reaches the working position, the operating force of the propulsion handle suddenly increases and does not move, and its corresponding position indicator light shows its position. The mechanical interlock of the handcart can reliably ensure that the handcart can only be closed when the handcart is in the working position or the test position; and the circuit breaker can only move when the circuit breaker is in the open state.

 

Compartment

The main electrical components of the switchgear have their own independent compartments, namely: circuit breaker handcart compartment, busbar compartment, cable compartment, relay instrumentation compartment, etc. The degree of protection between each compartment is IP2X. In addition to the relay instrumentation, the other three compartments each have a pressure relief channel. Thanks to the center-mounted form, the cable compartment space is greatly increased, so the equipment can be connected to multiple cables.

a) Busbar compartment A: The main busbar is a single-splicing joint that is connected to each other and fixed by a branch busbar (static contact box) and a main busbar insulating sleeve. The main busbar and the contact busbar are copper bars with a rectangular cross section and are used for double busbars for high current loads. For special needs, the busbars can be covered with heat shrink tubing and custom insulating covers. Insulating bushings are installed between adjacent cabinet busbars. If an internal fault arc occurs, the bushing can effectively limit the accident to the compartment without spreading to other cabinets.

b) Circuit breaker compartment B: Tracks are installed on both sides of the compartment for the handcart to move from the disconnected test position to the working position in the cabinet. The partition (removable door) of the static contact box is installed at the rear wall of the handcart compartment. When the handcart moves from the disconnected test position to the working position, the upper and lower shutters on the static contact box mouth are automatically linked with the handcart. Open; when moving in the opposite direction, the shutter automatically closes until the handcart retreats to a certain position and completely covers the static contact box to form an effective isolation. Since the upper and lower shutters are not interlocked, the valve on the charging side can be locked during maintenance, thereby ensuring that the maintenance personnel do not touch the charged body. The handcart can also be operated when the circuit breaker door is closed. Through the observation window on the door, you can observe the position/closing indication and energy storage status of the handcart in the compartment.

c) Cable compartment C: The switchgear is in the center-mounted type, so the cable compartment has a large space. The current transformer and grounding switch are installed on the rear wall of the compartment (the grounding switch can also be installed in the middle of the switch cabinet according to customer requirements), and the lightning arrester is installed in the lower part of the compartment. After removing the handcart and the extractable horizontal partition, the constructor can enter and install from the front. The cable connection conductors in the cable room can be connected to 1-3 cables in each phase. If necessary, 6 cables can be connected in each phase. The bottom of the cable compartment is equipped with a detachable metal sealing plate or non-magnetic metal. The sealing plate ensures the construction is convenient.

d) Relay instrument room D: The relay instrument room can be equipped with relay protection components, instruments, live display indicators and secondary equipment with special requirements. The control circuit is laid in the wire trough, and the wire trough has a metal cover plate to isolate the secondary wire from the high voltage component. The left front side slot is reserved for the introduction and extraction of the control cable, and the corresponding part of the bottom plate is provided with a secondary cable threading hole. A small busbar crossing hole for easy construction is left on the top plate of the electrical instrument room, and the top cover of the instrument room can be opened during wiring to facilitate the installation of the small busbar.

Pressure relief device

A pressure relief device is arranged above the handcart room, the busbar room and the cable room. When an arc occurs in the compartment, the air pressure inside the switchgear rises, and a special sealing ring installed on the front door closes the door. The top-loaded pressure relief metal plate is automatically opened to relieve pressure and high temperature gases, ensuring operator and switchgear safety.

Interlocking the position of the secondary plug and the handcart

The secondary connection of the switchgear and the handcart is realized by the contact of the secondary plug. The secondary plug is connected to the handcart through a nylon corrugated telescopic tube, and the secondary socket is installed at the upper right of the handcart room of the switchgear cabinet. . When the handcart is only in the test/disconnect position, the secondary plug can be locked when the second plug is inserted or removed. The circuit breaker handcart equipped with the closing and closing electromagnet is locked by the electromagnet before the secondary plug is turned on, and can only be opened and cannot be closed.

Live display device

The switchgear can be equipped with a live display device that detects the operation of the primary circuit. The device consists of a high voltage sensor and a display. The device can indicate the charging condition of the high-voltage circuit, and can also cooperate with the electromagnetic lock to realize the forced locking of the operating handle, the cabinet door and the adjacent cabinet, thereby preventing the mobile vehicle from being isolated from the load, preventing the grounding switch from being electrically connected, and preventing the accidental charging interval. The purpose is to improve the anti-missing performance of the accessory products.

Prevent condensation

In order to prevent condensation from occurring in environments with high humidity or large temperature variations, electric heaters are installed in the circuit breaker chamber and the cable compartment to prevent insulation accidents under the above operating conditions.

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A 5xa0mm grounding copper bar is separately provided in the cable room, and is connected to the adjacent cabinets and is well connected to the cabinet for direct grounding components. Since the entire cabinet is joined by aluminum-zinc plates, the entire cabinet is in a good grounding state, ensuring the safety of the operator when it touches the cabinet.

Prevent misoperation interlocks and working principle

The switchgear is equipped with a safe and reliable interlocking device, which fully meets the requirements of the “five defenses”.

a instrument room door is equipped with an introductory button or a KK-type transfer switch to prevent mis-matching and mis-dividing the circuit breaker;

b) When the circuit breaker handcart is only in the test or working position, the circuit breaker can be combined and operated, and after the closing, the handcart is locked and cannot move, to prevent pushing and pulling the car when the load is loaded;

c) The circuit breaker handcart can be moved from the test/disconnect position to the working position only when the grounding switch is in the open position; the earthing switch can only be closed when the circuit breaker handcart is in the test disconnect position ( The grounding switch can be equipped with a voltage display device), which prevents the grounding switch from closing the circuit breaker when the closing device is closed and prevents the grounding switch from being mischarged;

d) When the grounding switch is in the split position, the lower door and the rear door are blocked to prevent accidental entry into the charging interval;

e) The circuit breaker handcart with the closing and closing electromagnet according to the customer's requirements can prevent the manual or electric closing operation without unlocking the locking device;

f) When the circuit breaker handcart is in the working position, the secondary plug is locked and cannot be removed;

g) Electrical interlocks can be installed in each cabinet;

The switchgear can also be equipped with an electromagnet locking device on the grounding switch operating machine to improve reliability, and a reverse interlocking device for operating the cabinet back door and the grounding switch can be provided according to user requirements, and the order is selected according to the user's requirements.

Transportation, installation and commissioning

Shipping and storage precautions

a) The product is not allowed to tip over, invert and be subjected to severe vibration during loading and unloading, transportation, and the sling should be placed in the designated part of the packaging box or switchgear;

b) prevent rain, so as to prevent the product from getting wet;

c) When the switchgear arrives at the scene, the consignee should check whether the outer packaging of the goods is complete, whether the goods are damaged or short, and if necessary, notify the supplier to go to the site for joint inspection;

d) The shelf of the product should be stable and the electrical components and components must not be dismantled.

Switchgear installation

a) The surface of the base frame should be flat and 2-4 mm above the floor, and the tolerance of the frame flatness and straightness is 1 mm/m;

b) Adjust the position of the switchgear one by one on the basic frame, and the verticality shall not exceed 2mm. When the number of switch cabinets is more than 10, it is best to assemble from the middle. The switch cabinet is bolted or welded to the base frame;

c) In order to facilitate the installation of the main busbar, the installation of the switchgear should be alternated with the installation of the main busbar.

d) Connect the main grounding busbar of the switchgear with the prefabricated grounding busbar to the cabinet, and connect the main grounding busbar of the switchgear to the grounding pole of the power distribution room;

e) After the installation of the secondary cable and the secondary cable is completed, the gap around the cable threading hole should be sealed, and the sealing plate and the partition plate should be installed.

Switching device debugging

a) Check the insertion depth and contact of the isolation contacts are good;

b) After the switchgear is installed, it is necessary to carry out operation test, manually operate the circuit breaker, handcart and grounding switch, etc., and check the operation of all the mechanical interlocking procedures. The action should be accurate and should be flexible without jamming;

c) Check whether the mechanical characteristics of the circuit breaker meet the specified requirements, and conduct the operation test according to the specified maximum and minimum operating voltage. The joint should be normal;

d) performing a quenching test on the secondary circuit to check the correctness of the protection, control and signal loop actions;

e) The main loop resistance measurement, the loop resistance of the circuit breaker should not exceed the standard value;

f) The main circuit phase-to-phase and relative ground-to-power frequency withstand voltage test shall be carried out according to the handover acceptance regulations;

g) Secondary circuit insulation strength test 200V/min, there should be no breakdown flashover phenomenon. In the electronic device part of the secondary circuit, the test voltage is determined by the user and the manufacturer.

Switching device operating procedure

Although the switchgear is designed with the interlocking device to ensure the correct operation of each part, the operator should strictly operate the switchgear according to the operating procedures and the requirements of this technical document. It should not be operated at will, and should not be operated when the operation is blocked. Add analysis and forcibly operate, otherwise it will easily cause equipment damage and even cause accidents.

Circuit breaker cabinet operation without grounding switch

a) Insert the circuit breaker removable parts into the cabinet: install the circuit breaker handcart on the transfer vehicle and lock it, push the transfer vehicle to the front of the cabinet, lift the trolley to the proper position, and position the front of the transfer vehicle. Insert the lock plate into the partition socket in the cabinet and lock the transfer vehicle and the cabinet, open the locking hook of the circuit breaker trolley, and push the circuit breaker trolley into the cabinet and lock it at the same time. After confirming that the handcart and the cabinet have been locked, , unlock the transfer vehicle and the cabinet, and pull the transfer vehicle away.

b) Handcart operation in the cabinet: After the circuit breaker hand truck is installed in the cabinet, it is in the disconnected position. After the secondary plug of the auxiliary circuit is inserted, the handcart is in the test position. If the power is on, the test position indicator on the instrument panel heavy plate is on. At this time, the electric vehicle can be tested for electrical operation when the main circuit is not connected. If you want to continue the operation, you must first close all the doors and lock the door.

Make sure that the circuit breaker is in the open state. At this time, insert the handle handle of the handcart into the operation hole of the panel, turn the handle clockwise until the handle is obviously blocked and hear the clear switch of the auxiliary switch, and work on the instrument panel. The position indicator lights up and the handle is removed. At this time, the main circuit is turned on, and the circuit breaker is in the working position, and can be combined and divided by the control loop.

If you are ready to withdraw the trolley from the working position, first make sure that the breaker is in the open state, insert the handcart to operate the crank, turn counterclockwise until the rocker is blocked and hear the clear auxiliary switch switching sound, the car will return Test location. At this point, the main circuit has been completely disconnected and the metal shutter is closed.

c) Remove the handcart from the cabinet: When removing the handcart from the cabinet, make sure that the circuit breaker is in the open state, then release the auxiliary circuit secondary plug and lock the plug on the handcart frame. At this time, the transfer car will be transferred. Push to the front of the cabinet (same as when the handlebar is loaded into the cabinet) and lock it, then unlock the handcart and pull it out. When the handcart completely enters the transfer vehicle and confirms that it is locked with the transfer vehicle, the lock of the transfer vehicle and the cabinet is released, and the transfer vehicle is pulled back.

If the handcart is to be transported by a transfer vehicle for a long distance, care must be taken in the process of pushing the transfer car to avoid accidents such as tipping during transportation.

d) The circuit breaker hand truck is confirmed in the branching and closing state of the handcart; the branching and closing state can be judged by the dividing and closing signs on the panel of the circuit breaker handrail and the closing and closing indicators on the panel of the instrument room. If the green opening indicator on the handcart panel is seen through the middle panel observation window, it is determined that the circuit breaker is in the open state. At this time, if the secondary circuit of the auxiliary circuit is turned on, the opening indicator light on the instrument panel is illuminated. .

Circuit breaker cabinet operation with earthing switch

The procedure for pushing the circuit breaker trolley into and out of the cabinet is identical to the operation procedure of the circuit breaker cabinet without the grounding switch. The only points to note during the operation of the handcart in the cabinet and the grounding switch are as follows:

a) Handcart operation in the cabinet: When preparing to push the handcart into the working position, in addition to complying with the requirements mentioned in the previous section, it should also be confirmed that the grounding switch is in the open state, otherwise the next operation cannot be completed. .

b) Combined/divided grounding switch operation: If the grounding switch is to be grounded, first make sure that the handcart has been retracted to the test/disconnect position, and remove the propulsion rocker, then press the interlocking bending plate of the grounding switch operating hole to insert Grounding switch operating handle, turning 90° clockwise, will open the grounding switch to separate the operation of the isolation cabinet.

The isolation plug does not have the ability to switch load currents on and off, so it is not allowed to move the handcart under load. When performing the operation of the isolated handcart, it must be ensured that the circuit breaker that cooperates with it is first opened, and the auxiliary contact of the circuit breaker is opened and the electrical interlock on the isolated handcart is matched. Operate the isolated handcart. The specific operating procedures are the same as those for the circuit breaker trolley.

KYN28 switchgear is mainly based on mechanical interlocking, supplemented by electrical interlock to realize its "anti-error" function. If the operational resistance is found to increase during the interlocking operation, the interlocking device should be inspected in time on the premise of eliminating the possibility of misoperation.

Maintenance and maintenance of switchgear

The inspection and maintenance intervals of equipment/components (such as consumables) depend on the length of their operation, the frequency of operation, and the failure of the fault. According to the operating conditions and the on-site environment, the switchgear is inspected and maintained every 3-5 years.

a) Check the operation of the circuit breaker and the operating mechanism according to the requirements of the vacuum circuit breaker instruction manual, and make necessary adjustments and lubrication;

b) Check the working conditions of the whole process of entering and leaving the handcart, and adjust and lubricate if necessary;

c) Check that the interlock is flexible and reliable; adjust and lubricate if necessary;

d) Check whether the contact surface of the moving and static isolating contacts is damaged, whether the insertion depth meets the requirements, whether the spring pressure is weakened, whether the surface plating is abnormally oxidized, and the old conductive sound on the isolation contact is replaced;

e) Check the contact between the busbar and each conductive connection part and fasten the connection, and find that there is heat on the surface to be treated;

f) Check the grounding circuit part, such as the contact of the grounding contact, the main grounding wire and the grounding wire of the door, to ensure the continuity of its conduction;

g) Wipe the dust on the vacuum interrupter and the surface of the insulation with a soft cloth. If partial discharge occurs due to condensation, a thin silicone grease can be applied to the discharge surface as a temporary repair.

random document

a) product certification;

b) factory inspection report;

c) installation instructions;

d) secondary wiring diagram;

e) packing list;

f) special tools;

g) Technical documents and accessories such as the instruction manual of the main components of the switchgear

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a) main wiring plan diagram;

b) switch device arrangement and layout layout of the power distribution room;

c) the type, specification and quantity of the main electrical equipment in the switchgear;

d) secondary circuit diagram;

e) When the switchgear is used under special environmental conditions, it should be stated at the time of ordering;

f) Other special requirements.