Eco-friendly Gas-Insulated Ring Main Unit

Product Overview

Environmental-friendly gas-insulated AC metal-enclosed switchgear and control equipment (hereinafter referred to as “switchgear”) features green and environmentally friendly operation, reliable performance, enhanced safety, a compact structural design that minimizes space requirements, maintenance-free operation, long service life, and strong environmental adaptability.

The switchgear is a fully sealed system in which all live primary components and switches are enclosed within a stainless-steel enclosure, ensuring protection from environmental influences. The product features a modular design that allows for flexible arrangement according to different configuration schemes, enabling combinations of common-casing and expandable units to meet the compact switchgear requirements of various secondary transmission, distribution, and substation applications.

The switchgear has successfully passed type tests conducted by the National High-Voltage Electrical Apparatus Testing Center and is widely applicable in small secondary distribution substations, packaged switchgear stations, industrial and mining enterprises, airports, railways, commercial districts, high-rise buildings, expressways, subways, tunnels, and other environments with harsh natural conditions.

Implementation Standard

GB/T 311.1 Insulation Coordination — Part 1: Definitions, Principles, and Rules

GB/T 1984 High-Voltage AC Circuit Breakers

GB/T 1985 High-Voltage AC Isolating Switches and Earthing Switches

GB/T 3804 3.6 kV to 40.5 kV High-Voltage AC Load Switch

GB/T 3906 3.6 kV to 40.5 kV AC Metal-Enclosed Switchgear and Control Equipment

GB/T 4208 Degrees of Protection Provided by Enclosures (IP Code)

GB/T 11022 Common Technical Requirements for Standards of High-Voltage Switchgear and Control Equipment

DL/T 404 3.6 kV to 40.5 kV AC Metal-Enclosed Switchgear and Control Equipment

DL/T 402 High-Voltage AC Circuit Breaker

DL/T 593 Common Technical Requirements for Standards of High-Voltage Switchgear and Control Equipment

Standardized Design and Customization Scheme for 12kV Ring Main Units (Enclosures) (2020 Edition)

Product Features

1. Green and environmentally friendly

Zero greenhouse gas emissions; stringent control over the content of harmful chemical elements in raw materials across all components and manufacturing processes to minimize the generation of hazardous substances during production; and a material recycling rate of over 90% at the end of the product’s life cycle.

2. Strong environmental adaptability

All high-voltage components are sealed within an inflated metal enclosure, making them particularly suitable for harsh environments such as high altitudes, extreme cold, high humidity, salt spray, and pollution.

3. Minimal maintenance

High-voltage insulation is unaffected by external environmental conditions and is resistant to aging; the use of a vacuum arc-extinguishing chamber in place of a grounding switch for making short-circuit currents eliminates the limitations of conventional grounding switches, which cannot repeatedly and rapidly make short-circuit currents and require subsequent maintenance after such operations; furthermore, on-site SF6 gas leak detection and protection are unnecessary, thereby reducing the equipment’s total life-cycle cost.

4. Small size

Employing environmentally friendly gas insulation, it retains the dimensional advantages of gas-insulated switchgear, resulting in a compact cabinet design that saves floor space.

5. Safe and reliable

Micro-positive-pressure gas insulation is employed, which reduces the probability of gas leakage. Even if a gas compartment experiences a leak, sufficient dielectric strength is maintained at the minimum operational pressure (zero gauge pressure), ensuring uninterrupted normal operation.

Both the live parts and the switch body are sealed within a stainless-steel gas compartment and connected to the external circuit via bushings, thereby eliminating direct contact with live components. The equipment is equipped with a reliable pressure-relief device and pressure-release channels to ensure the safety of personnel and equipment in the event of a fault. In addition, it features a comprehensive mechanical interlocking system that effectively minimizes the risk of misoperation.

6. Modular Design

Switchgear equipment includes load switch units (C), circuit breaker units (V), metering cabinet units (M), busbar PT units, and more. Utilizing dedicated fully insulated and fully shielded busbar connectors, these components can be configured in a wide variety of combinations—up to four units can be housed within a single N2-insulated gas compartment—thereby maximizing flexibility to meet the diverse requirements of different regions, application scenarios, and customer needs and delivering a broad range of power supply and distribution design solutions.

7. Fully insulated and fully sealed design

The live primary components of the switchgear (the main busbar) and the switch unit itself are both sealed within a gas-insulated enclosure fabricated by welding stainless steel plates. The main circuit is connected to external equipment via bushings installed on the enclosure, which comply with the DIN 47636 standard. Connection to incoming and outgoing cables is achieved through fully insulated, fully shielded, and fully sealed separable connectors. The enclosure meets an IP67 protection rating, ensuring that the internal environment remains unaffected by external conditions and providing short-term resistance to flooding and condensation.

8. New Mechanism

The new spring-operated mechanism features optimized components and a simplified transmission design, resulting in greater overall stability and more flexible actuation, while also enabling scalable intelligent control. The interlocking system employs rigid connections, which are more reliable than flexible ones. Components, microswitches, and circuit boards are integrated in a modular fashion, facilitating maintenance and troubleshooting.