High Voltage Complete Switchgear Cabinet
Product Title
Product Details
The KYN28A-12 indoor AC metal-enclosed armored middle-placed switchgear. It is suitable for three-phase AC rated voltage 12kV, rated frequency 50Hz power systems, used for receiving and distributing electrical energy and for controlling, protecting, and monitoring circuits.
Applicable 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 Controlgear for Rated Voltages Above 1kV and Up to 50kV"
DL404-97 "Technical Conditions for Ordering Indoor AC High-Voltage Switchgear"
The switchgear is designed according to GB3906-91 for armored metal-enclosed switchgear. The whole is composed of two main parts: the cabinet and the middle-placed withdrawable component (i.e., the trolley) (see figure). The cabinet is divided into four separate compartments. The enclosure protection level is IP4X, and the level is IP2X when the doors between compartments and the circuit breaker compartment are open. It has various functional schemes such as overhead incoming/outgoing, cable incoming/outgoing, etc. After arrangement and combination, it forms a complete distribution system device. This switchgear can be installed, debugged, and maintained from the front, so it can be placed back-to-back to form double rows or installed against the wall, improving the safety and flexibility of the switchgear and reducing the floor space.
Enclosure and Others
The main frame of the switchgear uses aluminum-zinc plated steel sheet, processed by CNC machines and using multiple folding processes. This gives the entire cabinet not only high precision and strong corrosion and oxidation resistance but also, due to the multiple folding processes, the cabinet is lighter in weight, has higher mechanical strength, and is more aesthetically pleasing than similar equipment cabinets. The cabinet uses an assembled structure, connected with rivet nuts and high-strength bolts. This results in a short processing cycle, strong component interchangeability, small floor space, and easy production organization.
Trolley
The trolley frame is assembled from steel sheets processed by CNC machines. The trolley matches the cabinet insulation, and the mechanism interlocking is safe, reliable, and flexible. Depending on the purpose, trolleys can be divided into circuit breaker trolleys, voltage transformer trolleys, metering trolleys, disconnector trolleys, and so on. Various types of trolleys are modular and interchangeable; trolleys of the same specification can be freely interchanged ****.
The trolley has three positions in the cabinet: disconnected position, test position, and working position. Each position is equipped with a positioning device to ensure reliable interlocking. The interlocking anti-misoperation procedure must be followed. Various trolleys are moved in and out by a nut and screw mechanism, which is light and flexible to operate, suitable for operators. When the trolley needs to be removed from the cabinet, a dedicated transfer truck can be used to easily withdraw it for various inspections and maintenance. Moreover, being a middle-placed type, the entire trolley is compact, making inspection and maintenance very convenient.
Compartments
The main electrical components of the switchgear have their own independent compartments, namely: circuit breaker trolley compartment, busbar compartment, cable compartment, and relay instrument compartment. The protection level between each compartment reaches IP2X. Except for the relay instrument room, the other three compartments each have their own pressure relief channels. Due to the middle-placed design, the cable compartment space is significantly increased, allowing the equipment to connect multiple cables.
a. Circuit Breaker Compartment
Rails are installed on both sides of the partition for the trolley 15 to slide from the disconnected position and test position to the working position inside the cabinet. The partition 13 (shutter) of the fixed contact housing 6 is installed on the rear wall of the trolley compartment. When the trolley moves from the disconnected/test position to the working position, the shutters on the upper and lower fixed contact housings are linked with the trolley and open automatically. When moving in the opposite direction, the shutters close automatically until the trolley retreats to a certain position, completely covering the fixed contact housings, forming effective isolation. Since the upper and lower shutters can be operated separately, the shutter on the live side can be locked during maintenance, ensuring that maintenance personnel do not touch live parts. When the circuit breaker compartment door is closed, the trolley can still be operated. Through the observation window on the middle door, the open/closed position of the trolley switch and the energy storage status can be observed.
b. Busbar Compartment
The main busbar 4 is spliced and connected through each single cabinet. It is fixed via the branch busbar 2 and the fixed contact housing. The main busbar and connecting busbar are copper bars with rectangular cross-sections. For high-current loads, double busbars are used. The branch busbar is bolted to the fixed contact housing 6 and the main busbar without requiring other supports. For special needs, the busbar can be covered with heat-shrinkable sleeves, and the connecting bolts with insulating sleeves and end caps. Adjacent cabinet busbars are fixed with bushing 3. The air buffer retained between the connected busbars can prevent melting in case of an internal fault arc. Bushing 3 can effectively confine the accident within the cabinet without spreading to other cabinets.
c. Cable Compartment
The switchgear adopts a middle-placed design, hence the cable compartment is relatively spacious. Current transformers 7 and earthing switches 8 are installed on the rear wall of the compartment, and arresters 10 are installed at the lower rear part of the compartment. After opening the lower door, workers can enter the cabinet from below for installation and maintenance. The cable connection conductors in the cable compartment can each phase accommodate 1 to 3 single-core cables. If necessary, each phase can accommodate up to 6 single-core cables. The bottom of the cabinet for cable incoming is equipped with slotted detachable non-metallic or non-magnetic metal sealing plates, ensuring construction convenience.
d. Relay Instrument Room
The relay instrument room can accommodate relay protection components, instruments, live monitoring indicators, and secondary equipment for special requirements. Control cables are laid in sufficiently spacious cable ducts with metal covers, isolating secondary cables from the high-voltage compartment. The left-side cable duct is reserved for the introduction and extraction of control small busbars. The internal control cables of the switchgear are laid on the right side. The top plate of the relay instrument room also has small holes for easy installation of small busbars. During wiring, the top cover plate of the instrument room can be flipped for easy installation of small busbars.
Anti-Misoperation Interlocking Device
The switchgear has a reliable interlocking device that fully meets the "five-prevention" requirements.
a. The instrument room door is equipped with a push-button or KK-type selector switch to prevent accidental closing or opening of the circuit breaker.
b. The circuit breaker can only be opened or closed when the circuit breaker trolley is in the test or working position. After the circuit breaker is closed, the trolley cannot be moved, preventing the accidental pushing or pulling of the circuit breaker under load.
c. Only when the earthing switch is in the open position can the circuit breaker trolley be moved from the disconnected/test position to the working position. Only when the circuit breaker trolley is in the test/disconnected position can the earthing switch be closed (the earthing switch can be equipped with a voltage indicating device). This prevents closing the earthing switch with live parts and closing the circuit breaker when the earthing switch is in the closed position.
d. When the earthing switch is in the open position, the lower door and rear door cannot be opened, preventing entry into live compartments.
e. When the circuit breaker trolley is indeed in the test or working position but there is no control voltage, only manual opening is possible, not closing.
f. When the circuit breaker trolley is in the working position, the secondary plug is locked and cannot be removed.
g. Each cabinet can be equipped with electrical interlocking.
This switchgear can also be equipped with an electromagnetic locking device on the earthing switch operating mechanism to improve reliability, subject to the user's choice when ordering.
Pressure Relief Device
Pressure relief devices are installed above the circuit breaker trolley compartment, busbar compartment, and cable compartment. When an internal fault arc occurs in the circuit breaker or busbar, the pressure inside the switchgear increases with the appearance of the arc. The special sealing rings installed on the doors seal the front. The pressure relief metal plates installed on the top will open automatically, releasing pressure and exhausting gases, ensuring the safety of operators and the switchgear.
Secondary Plug and Trolley Electrical Interlocking
The connection between the secondary cables of the switchgear and the secondary cables of the circuit breaker trolley is achieved through a manual secondary aviation plug. The moving contacts of the secondary plug are connected to the circuit breaker trolley via a nylon corrugated伸缩 tube. The secondary fixed contact socket is installed on the upper right side of the trolley compartment. The secondary plug can only be inserted and removed when the circuit breaker trolley is in the test/disconnected position. When the circuit breaker trolley is in the working position, the secondary plug is locked by mechanical interlocking and cannot be removed.
Live Display Device
If required by the user, the switchgear can be equipped with an optional live display device for detecting the status of the primary circuit. This device consists of a high-voltage sensor and a display unit. This device not only indicates the energization status of the high-voltage circuit but can also be used with an electromagnetic lock to achieve forced interlocking of the earthing switch handle and the door, preventing the closing of the earthing switch with live parts and preventing entry into live compartments, thereby improving the anti-misoperation performance of the product.
Anti-Condensation and Corrosion
To prevent the hazards of condensation in climatic environments with high humidity or large temperature variations, heaters are installed in the circuit breaker compartment and cable compartment to prevent corrosion during use in such environments.
Grounding Device
A separate 5×40mm grounding copper busbar is installed in the cable compartment, running through adjacent switchgear and making good contact with the cabinet body. This grounding busbar is used for components that require direct grounding. At the same time, since the entire cabinet is assembled from aluminum-zinc plated sheets, the entire cabinet is in a good grounding state, ensuring the safety of operators touching the cabinet.
| Item | Unit | Value |
|---|---|---|
| Rated Voltage | kV | 3.6, 7.2, 12 |
| Rated Frequency | Hz | 50 |
| Circuit Breaker Rated Current | A | 630, 1250, 1600, 2000, 2500, 3150 |
| Switchgear Rated Current | A | 630, 1250, 1600, 2000, 2500, 3150 |
| Rated Short-time Withstand Current (4S) | kA | 16,20,25,31.5,40,50 |
| Rated Peak Withstand Current (Peak) | kA | 40,50,63,80,100,125 |
| Rated Short-circuit Breaking Current | kA | 16,20,25,31.5,40,50 |
| Rated Short-circuit Making Current (Peak) | kA | 40,50,63,80,100,125 |
| Rated Insulation Level - 1min Power Frequency Withstand Voltage | kV | 24, 32, 42 |
| Rated Insulation Level - Lightning Impulse Withstand Voltage | kV | 40, 60, 75 |
| Protection Level | Enclosure IP4X, between compartments and when circuit breaker compartment door is open IP2X. |
◇ Ambient air temperature: maximum +40C, minimum -15C.
◇ Relative humidity: daily average relative humidity ≤95%; daily average water vapor pressure not exceeding 2.2KPa; monthly average relative humidity ≤90%; monthly average water vapor pressure not exceeding 1.8KPa.
◇ Altitude: below 1000m.
◇ Seismic intensity: not exceeding 8 degrees.
◇ Ambient air should not be significantly contaminated by corrosive or flammable gases, water vapor, etc.
◇ No severe vibration sites.
◇ If the conditions exceed the normal conditions specified in GB3906, the user and our company should negotiate.
| Cabinet Width A | Cabinet Depth B | L1 | L2 | L3 | L4 |
|---|---|---|---|---|---|
| 800 | 1500 Cable | 530 | 630 | 150 | 490 |
| 800 | 1660 Overhead | 530 | 630 | 310 | 650 |
| 800 | 1500 Cable | 730 | 830 | 150 | 490 |
| 1000 | 1660 Overhead | 730 | 830 | 310 | 650 |
The trolley frame is assembled from steel sheets processed by CNC machines. Depending on the purpose, trolleys can be divided into circuit breaker trolleys, voltage transformer trolleys, disconnector trolleys, metering trolleys, etc. Trolleys of the same specification can be easily interchanged. The trolley has three positions in the cabinet: isolated position, test position, and working position. Each position is equipped with a positioning device to ensure the trolley cannot move arbitrarily when in these positions. The trolley must be unlocked to move.
The busbar is routed from one switchgear to another and fixed through branch busbars and fixed contact housings. The flat branch busbar is bolted to the fixed contact housing and the main busbar without requiring any other support or fastening devices. When the user has special requirements for several groups, the mechanical interlocking of the connection bolts in the busbar compartment and the phase分隔板 are fixed with busbar bushings when the busbar compartment partition is opened. If an internal fault arc occurs, it can limit the accident from spreading to adjacent cabinets and ensure the mechanical strength of the busbar.
The cable compartment can accommodate current transformers, earthing switches, arresters, and cables. Its bottom is equipped with slotted detachable plates to facilitate on-site construction.
The relay instrument room is used for installing various relays, instruments, signal indicators, protection switches, and other components. Additionally, small busbars can be added on top of the instrument room according to user requirements for laying test control small busbars.
Pressure relief devices are installed above the trolley compartment, busbar compartment, and cable compartment. When an internal fault arc occurs in the circuit breaker, main busbar, or cable compartment, the pressure inside the switchgear increases with the appearance of the arc. When the pressure reaches a certain level, the pressure relief metal plates installed on the top will be pushed open automatically, releasing pressure and exhausting gases, ensuring the safety of operators and the switchgear.
A specially designed latch structure for interlocking between cabinets, combined with the door mechanism, makes the middle door tighter and more secure. When the middle door is manually closed, its connection strength with the cabinet is good, enhancing the ability to effectively withstand internal arc faults.
KYN28A-12 Armored Withdrawable Metal-enclosed Switchgear|10KV Indoor High-Voltage Switchgear
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