12kV Outdoor Gas Insulated Ring Main Unit

12kV Outdoor Gas Insulated Ring Main Unit

We have been focusing on the production of high-voltage switchgear and control equipment, Extractable Switchgear, Fixed Type switchgear and pursuing the brand strategy. Our products are sold all over the world, the reliable quality assurance and enthusiastic after-sales service have enabled us to occupy the market. We've got in-house testing facilities where our items are tested on every single aspect at different processing stages. At present our sales network is growing continually, improving service quality to meet customer's demand.

12kV Ring Main Unit RMU Switchgear is expandable, suitable for medium voltage secondary distribution network, with 10 different types of configurations, suitable for switching systems up to 36kV.

One of the main advantages of rmu switchgear is to provide users with higher security. The switchgear is located in the ring network. When the first-line power supply is turned off, the line network is connected to the two-line power supply, and the second-line power supply can be used for power supply.

The 12kV ring main unit can provide 4 ways, 5 ways or 6 ways of standard configuration and other equipment according to customer requirements. All rmu combinations are designed according to the IEC62271 standard.

Air insulated ring network cabinet is a term corresponding to compact gas insulated ring network cabinet. In the early days, air insulated ring network cabinets used VEI vacuum or compressed air load switches, gas producing load switches, and other ring network cabinets. Later, with the widespread use of SM6, it became the main stream of air insulated ring network cabinets. Like other air ring network cabinets, the load switch has been replaced with an SF6 air bag type, which means that the load and grounding three-position switch is installed inside an epoxy resin cast insulation shell. SF6 as arc extinguishing and insulation medium

Air insulated ring network cabinet - expandable SF6 ring network cabinet, can be freely combined, has a small size, is safe and reliable, and does not require maintenance.

SF6 gas is used as insulation and arc extinguishing medium, and the constant magnetic field arc rotation method ensures strong arc extinguishing ability, good breaking performance, low overvoltage, long electrical life, and maintenance free arc extinguishing chamber.

The load switch - fuse combination electrical appliance has a three position function, perfect sealing, reliable operating mechanism and locking.

The grounding switch has a short-circuit closing function.

The cabinet body is formed by stamping and bending with aluminum coated zinc sheet, which is sturdy and reliable.

96 hour salt spray test conducted by the institution.

The insulated busbar of the main busbar shall be separated by metal partitions between cabinets and shall not generate eddy currents. Both ends of the busbar shall be sealed with insulation sealing.

Measures to prevent electric field concentration and partial discharge shall be taken at the junction of main bus.

The fuse grading cover ensures the insulation performance of the switch cabinet, without electric field concentration and partial discharge.

The ring network cabinet includes the following intervals: switch interval, bus interval, cable interval, mechanism interval, and control protection interval

1) Load switch

Load switches have a certain on-load breaking capacity, which means they can be energized to open and close under light loads, but they cannot be operated frequently. Generally, load switches are equipped with fuses and have stronger arc extinguishing ability than isolation switches.

2) Isolation switch

When the circuit breaker disconnects the circuit, the disconnection of the isolation switch allows for a clear separation of the live and dead parts, serving as an auxiliary switch.

Due to the lack of intuitive external indicators for the contact position of circuit breakers, and in some cases, it cannot be guaranteed that its indication is consistent with the position of the contact, it is necessary to use isolation switches to clearly separate the energized and non energized parts.

In addition, the isolation switch has a certain natural arc extinguishing ability, which is commonly used for the input and disconnection of low current equipment such as voltage transformers and lightning arresters, as well as the connection between a circuit breaker and several devices, making the switching of the circuit breaker through the isolation switch more flexible and convenient.

3) Circuit breaker

A switching device that can close, carry, and disconnect the current under normal circuit conditions, and can close, carry, and disconnect the current under abnormal circuit conditions within a specified time.

4) Grounding switch

Mainly used for equipment maintenance, in order to prevent sudden power calls during the maintenance process, both ends of the maintenance equipment must be grounded.

The grounding switch of the high-voltage distribution cabinet is generally grounded on the output load side. When repairing the load side of the high-voltage distribution cabinet (such as tightening bolts, disassembling cables, etc.), we need to disconnect the switch and close the grounding switch of the distribution cabinet at the same time. This can prevent sudden power calls from causing electric shock accidents, and also discharge the remaining charge, which is beneficial for maintenance safety

Features of 12kV RMU Switchgear:

The Ring6 12kV ring main unit (rmu) is designed as a compact switchgear. The completely sealed tank is filled with sf6 gas. All live components are contained in it. A tank can hold up to 6 modules. This advanced design can ensure the stability of the switch cabinet and the safety of the operator.

Ring6 RMU switchgear provides two ways to protect the transformer: load switch fuse protector combination device and circuit breaker with relay protection. Load switch fuse protector combination device is used for transformers of 1600kVA and below.

Circuit breakers with relay protection are used to protect transformers of various capacities. According to customer requirements, Ring6 can be equipped with an integrated remote control and monitoring unit.

In addition, when the rmu of one unit is damaged, other units can be connected to the same function. Although the main power supply is a single-circuit power supply, it is similar to the bidirectional power supply from each distribution branch, so this feature can improve the reliability of the power supply.

Routine tests will be performed on each unit before dispatch, and the installation will be carried out in full accordance with the circuit diagram.

The ring main unit is composed of incoming and outgoing wires. Usually the incoming wire is designed as a vacuum circuit breaker module, and the outgoing wire is connected to the transformer.

•  Adopting a fully assembled structure, it is lightweight and beautiful, and can be installed in any combination, making it easy for unlimited expansion and extension.
• It can be equipped with FN12-12 type compressed air load switch and combination appliance, as well as FZN25-12 type vacuum load switch and combination appliance. Small size, maintenance free, three-phase linkage structure, with obvious isolation fractures.
• The installation method of load switches and combination appliances is flexible, and they can be installed on the left and right sides, front and back (FZN25 cannot be upside down).
• It can be operated manually and electrically, and can have remote control function.
• There is no complete and reliable mechanical linkage and interlocking device, fully achieving the "five prevention" function.

When the load switch is closed, the grounding switch cannot be closed and the front door cannot be opened;

• • When the load switch is opened, the grounding switch can be closed. When the grounding switch is closed, the front door can be opened;
  • When the grounding switch is closed, the load switch cannot be closed and the front door panel can be opened;
  • When the grounding switch is opened, the load switch can be opened and closed, and the front door panel cannot be opened;
  • When the cable enters, the electromagnetic lock controls the front door panel to prevent it from opening, regardless of whether the load switch is in the closed or open position, when the incoming line is energized. (Emergency unlocking with key).
• The load switch adopts a linked protective insulation valve or transparent insulation cover to shield the live contacts.
• Adopting positive operation and maintenance, reliable wall installation.
• The front door is equipped with an observation window, which can clearly observe the working condition of the components inside the cabinet.

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