12KV 1250A Ring Main Unit High Current Medium Voltage Switchgear

Step into the future of medium voltage power distribution with Kexunan's 12KV 1250A Ring Main Unit High Current Medium Voltage Switchgear. As a reputable manufacturer equipped with an advanced factory, Kexunan is dedicated to delivering high-quality solutions tailored for medium voltage applications. Our meticulously crafted RMU switchgear, designed for high current scenarios, showcases our commitment to manufacturing excellence. Choose Kexunan as your trusted manufacturer and leverage the capabilities of our cutting-edge factory, ensuring superior standards of durability and performance. Elevate your medium voltage infrastructure with Kexunan's reliable and efficient RMU switchgear solutions, setting a new benchmark in the industry.

In recent years, with the advancement of technology, engineering construction has become increasingly intricate. This is mainly due to the demand for smaller, smarter switch equipment requiring less upkeep. Consequently, switch manufacturing companies, both domestic and international, are actively working on the development of medium voltage gas-filled cabinets, also referred to as gas-insulated switchgear (C-GIS). A gas-insulated switchgear encloses high-voltage elements like busbars, circuit breakers, isolating switches, and power cables within a shell with reduced gas pressure.

1. The switchgear can be made smaller by using sulfur hexafluoride gas as a medium for insulation and extinguishing arcs, resulting in a more compact and reduced design.

2. The main circuit's reliable and safe conductive part is sealed within SF6 gas, ensuring that the high-voltage live conductor remains enclosed and unaffected by external factors. This guarantees the equipment's long-term safe operation and high reliability.

3. There is no risk of electric shock or fire.

4. The switchgear is designed with an independent modular structure, where the air box is made of precise aluminium plates and can be disassembled. The isolation switch uses a linear transmission with three positions. An additional control module with nearly 100 PLC points is included for grounding, isolation switch, and remote operations to minimize control relays and circuit confusion. The modular mechanism switch connects opening and closing points with plum blossom contacts. This eliminates the possibility of non-operation in the original rotary isolation switch and grounding switch, resolves the issue of unstable and excessive contact resistance in the original rotary isolation switch, and includes shielding and voltage equalization covers on each contact's exterior to address partial discharge problems during switch breakpoints production.

5. The gas-insulated switchgear is convenient and flexible to use and arrange. It can be used as an independent unit and meet various main wiring requirements through combination. Delivering it to the site as units can shorten on-site installation and improve reliability.

12KV 1250A Ring Main Unit High Current Medium Voltage Switchgear Execution standards

GB/T11022-1999 Common technical requirements for high-voltage switchgear and control equipment standards

GB3906-2006 3.6kV~40.5kV AC Metal Enclosed Switchgear and Control Equipment

GB311.1-1997 Insulation Coordination of High Voltage Transmission and Transformation Equipment

GB/T16927.1-1997 High voltage testing technology Part: General test requirements

GB/T16927.2-1997 High voltage testing techniques Part 2: Measurement systems

GB/T7354-2003 Partial discharge measurement

GB1984-1989 AC High Voltage Circuit Breakers

GB3309-1989 Mechanical tests of high-voltage switchgear at room temperature

GB4208-2008 Code for Degree of Protection Provided by Enclosures (IP)

GB12022-2006 Industrial sulfur hexafluoride

GB8905-1988 Guidelines for gas management and inspection in sulfur hexafluoride electrical equipment

GB11023-1989 Test method for sulfur hexafluoride gas sealing of high-voltage switchgear

GB/T13384-1992 General technical requirements for packaging of electromechanical products

GB4207-2003 Solid insulation materials - Determination of relative and resistance to electrical trace index under humid conditions

GB/T14598.3-2006 Electrical relays - Part 5: Insulation of electrical relays

GB/T17626.2-1998 Electromagnetic Compatibility Testing and Measurement Techniques - Electrostatic Discharge Reactance Interference Test

GB/T17626.4-2008 Electromagnetic Compatibility Testing and Measurement Techniques - Electrical Fast Transient Pulse Group Immunity Test

GB/T17626.5-2008 Electromagnetic Compatibility Testing and Measurement Techniques - Surge (Impulse) Immunity Test

GB/T17626.12-1998 Electromagnetic Compatibility Testing and Measurement Techniques - Oscillating Wave Immunity Test

12KV 1250A Ring Main Unit High Current Medium Voltage Switchgear Test Type

◆ Insulation test

◆ Temperature rise test

◆ Loop resistance measurement

◆ Short-time withstand current and peak withstand current tests.

◆ Verification of making and breaking capabilities

◆ Mechanical operation and mechanical characteristic testing tests

◆ Protection level detection

◆ Additional tests on auxiliary and control circuits

◆ Pressure tolerance test for inflatable compartments

◆ Sealing test

◆ Internal arc test

◆ Electromagnetic compatibility test

12KV 1250A Ring Main Unit High Current Medium Voltage Switchgear Basic Scheme

Operation Condition

Technical Parameter

Grounding and Separation

The C-GIS gas-insulated high-voltage switchgear is offered in various current levels, such as 630A, 1250A, 1600A, 2000A, 2500A, 3150A, etc. The size of the cabinet can be customized to meet specific needs. The outer casing is made of a plate coated with aluminium zinc, while the gas box is assembled using high-quality stainless steel plates (304 grade). Each unit can be expanded and combined independently based on the design plan. The cabinet is divided into different sections: a secondary control room, busbar room, circuit breaker room, circuit breaker operating mechanism room, and cable room. The height of the cable connection can reach 700mm, enabling easy maintenance and installation. The cabinet is also equipped with a comprehensive grounding protection system. The switchgear comprises isolated functional compartments, including switch rooms, busbar rooms, cable rooms, and secondary circuit channels. A grounding metal partition separates each functional compartment, ensuring separate operation.

Secondary control room

The cabinet is located directly beneath the secondary control room. Inside the cabinet, there are panels where you can add components, as well as brackets for securely attaching terminal blocks. The secondary control room is designed to accommodate various devices, including wiring terminals, small busbar terminals, and comprehensive protection devices. These devices enable the system to perform functions like remote control, telemetry, remote signalling, and local monitoring. Circular openings on the side panels and terminals make connecting the cabinet with small busbars easier.

Busbar Compartment

The upper air box contains both the busbar room and the isolation mechanism. When the cabinet is placed on the ground support, the circuit cabinets and busbars on both sides are connected by merging the cabinets.

Switch Room

The switch cabinet with gas insulation has a flat layout with two chambers stacked on top of each other in the cabinet's centre. The top chamber has a three-position switch for isolation, while the bottom chamber houses a circuit breaker with a vacuum. The busbar, switch, and breaker are arranged vertically. The design of a single chamber is straightforward, cost-effective, and easy to make, but it is less reliable because the components are close together. On the other hand, the multi-chamber structure ensures greater safety by preventing interference between components and allowing for convenient replacement. However, this alternative is more complex, difficult to manufacture, and costly.

Institutional Room

The spring-based arrangement is placed horizontally, clearly separating the isolation and circuit breaker mechanism. It is designed to work with the insulation rod of the vacuum arc extinguishing chamber, both before and after, which helps simplify the transmission process. The mechanism's performance characteristics closely align with the circuit breaker's opening and closing functions, resulting in reduced energy usage and enhanced mechanical reliability and flexibility.

Cable Room

The cabinet is on top of the cable room and includes a path to release pressure. The distance between the ground and the cable connection terminals can be as high as 700mm. To comply with regulations, the cable room has grounding interlocks, allowing for the installation of two cables and lightning arresters in each circuit. Moreover, the internal cone insertion method connects the incoming and outgoing cables and the lightning arresters.