Medium Voltage Distribution Cabinet
This device is indoor metal-clad withdrawable switchgear (hereinafter referred to as switchgear), is a 3.6-12kV three- phase AC 50Hz single busbar and single busbar sectionalized system of the complete set of power distribution equipment is mainly used for power plants, small and medium-sized generators to send power, industrial, mining and industrial enterprises and power distribution and electric system of the secondary substation of the power receiving, sending and large-scale high-voltage motor starter and so on.
The switchgear meets the requirements of IEC298GB3906 and other standards, and has the interlocking functions of preventing pushing and pulling the circuit breaker trolley with load, preventing the circuit breaker from being mistakenly opened and closed, preventing the circuit breaker from being closed when the earth switch is in the closed position, preventing from mistakenly entering into the electrified room, and preventing the earth switch from being mistakenly closed when the electricity is charged,and it can be equipped with both the vacuum circuit breaker of VSI, and the VD4 vacuum circuit breaker of ABB. VD4 vacuum circuit breaker of ABB. It is a kind of power distribution device with superior performance.
| Item | Unit | Date | |
| Matching circuit breaker | |||
| ZN63A-12(VS1)Type | VD4 Type | ||
| Ratedvoltage | kV | 12 | 12 |
| 1min Frequency withstand voltage | kV | 42 | 42 |
| Ratedimpulse withstand voltage(peak) | kV | 75 | 75 |
| Ratedfrequency | Hz | 50 | 50 |
| Ratedcurrent | A | 630、1250、1600、2000、2500、3150、4000、5000 | |
| Branch busbar rated current | A | 630、1250、1600、2000、2500、3150、4000、5000 | |
| Rated short-time withstand current(RMS) | kA | 16、20、25、31.5、40、50 | 16、20、25、31.5、40、50 |
| Rated peak withstand current | kA | 40、50、63、80、100、125 | 40、50、63、80、100、125 |
| Ratedshort circuit duration | s | 4 | |
| Protection class | IP4X for the enclosure, IP2Xwith compartment door and handcart compartment door open. | ||
| Weights | kg | 700-1200 | 700~1200 |
The switchgear is designed according to the armored metal-enclosed switchgear in GB3906-91.The rectifier body is composed of two major parts: the cabinet and the center-mounted withdrawable parts(both handcart), see Fig.1.the cabinet is divided into four separate compartments with shell protection level of IP4, and the protection level of each small compartment and circuit breaker compartment is IP2X when the door is open.it has the overhead inlet and outlet lines, the cable inlet and outlet lines, and other functional programs, and it can be the power distribution device in the form of various programs by arranging and combining them. The switchgear can be installed, commissioned and maintained from the front, so it can be installed back-to-back in a double arrangement and against the wall, which improves the safety and flexibility of the switchgear and reduces the floor space.
A. Busbar room B.Circuit breaker handcart room C.Cable room D.Relay instrumentation room 1.Shell 2.Branching small busbar 3.Busbar casing 4.Main busbar 5.Static contact device 6.Contact box 7.Current Transformer 8.Earth switch 9.Cables 10.Lightning arrester | 11. Connection to the main busbar 12. Base plate 13. Control mini busbar 14. Earth switch operating mechanism 15. Extractable horizontal partition 16. Heating device 17. Circuit breaker hand truck 18. Secondary plug 19. Partitions(flaps) 20. Loading and unloading partition 21.Pressure relief channels |
 | A Handcart B Bus room C Cable room D Relay instrumentation room Pressure relief device Locking structure |
A Handcart
The skeleton of the handcart is made of thin steel plate processed by CNC machine and then riveted and welded. According to the use, the handcart can be divided into circuit breaker handcart, voltage transformer handcart, isolation handcart, metering handcart, etc.the same specifications of the handcart can be easily interchanged. Handcart in the cabinet has a medical position, test when the position and work position, each when there is no positioning device to ensure that the handcart in the dry above position when the extension can not be moved, and move the car must be required to lift the interlock.
B Bus room
The busbar leads from one switchgear cabinet to another and is secured by branch busbars and static contact boxes. The flat branch busbars are bolted to the static contact boxes and the main busbars without any other clamps or insulator connections. When required by the user and the project, the coupling bolts on the busbar rows can be encapsulated with insulation and end caps. Where busbars traverse switchgear bulkheads, they are secured with busbar bushings. In the event of an internal fault arc, the spread of the accident to neighboring cabinets is limited and the mechanical strength of the busbar is safeguarded.
C Cable room
Current transformers, earth switches, surge arresters and cables can be installed in the cable room, and a removable aluminum plate with slits at the bottom is provided to ensure easy on-site construction.
D Relay instrumentation room
The relay and instrumentation room is used for installing all kinds of relays, instruments, signal indication, operation switches and other components. In addition, according to user requirements in the instrumentation room at the top of the increase in small bus room, can be laid sixteen control small bus.
Pressure relief device
A pressure relief device is provided on the top of the trolley room, busbar room and cable room. When an internal fault arc occurs in the circuit breaker or main busbar or cable room, along with the arc,the air pressure inside the switchgear cabinet rises and reaches a certain pressure after which the pressure-release metal plate of the top device will be opened automatically to release the pressure and discharge the gas to ensure the safety of the operator and the switchgear cabinet.
Locking structure
The connection between the center door and the cabinet adopts the locking structure and is equipped with a lifting mechanism, which makes it more convenient to open the center door, and when the center door is in the closed state, the strength of its connection with the cabinet is better, which strengthens the ability of effectively resisting the internal arc failure.
