HXGN 口-12 (SF6) Unit Type AC Metal-Enclosed Ring Main Unit Switchgear | 12kV SF6 RMU

HXGN 口-12 (SF6) Unit Type AC Metal-Enclosed Ring Main Unit (RMU) Switchgear

The HXGN□-12 (SF6) unit type AC metal-enclosed ring main unit, also known as the ring network cabinet, is a new-generation high-voltage electrical product independently designed and developed based on domestic agricultural electricity and urban grid transformation needs. By introducing advanced overseas technology, this RMU meets and exceeds the technical performance requirements of IEC 298 and GB3906 standards.

Technical Features and Configuration

The main switch, operating mechanism, and key components of the ring main unit use ABB original parts or imported SFL-12/24 switchgear, ensuring high reliability and stable operation. Depending on user requirements, HAD/US type SF6 switches from ABB can also be installed. The circuit breaker operation is available in both manual and electrical modes, with optional VD4-S vacuum circuit breakers.

The cabinet body is manufactured with precision CNC processing and riveted for superior strength. It provides IP3X protection level and features complete mechanical interlocking and misoperation prevention. The product is compact, lightweight, durable, visually appealing, easy to operate, environmentally friendly, and maintenance-free.

Compliance and Standards

Complies with IEC 62271-202: High-voltage switchgear and control equipment – Part 202: HV/LV prefabricated substations.

Operating Conditions

a. Ambient air free from corrosive or flammable gases, vapors, or severe pollution.
b. Relative humidity: daily average ≤95%, monthly average ≤90%.
c. Altitude ≤2000 m.
d. No frequent vibration.
e. Ambient temperature: -25°C to +40°C.

Application and Function

The HXGN□-12 (SF6) ring main unit operates at AC 50Hz, 12kV and serves as a reliable device for electrical energy distribution and reception in power systems. It primarily uses ZFN□-10/630 vacuum load switches with air insulation and offers flexible configurations for incoming and outgoing cabinet schemes.

1. Incoming Cabinet Scheme

Includes a ZFN□-10/630 vacuum load switch, isolating knife, and grounding knife—all integrated into a single interlocked mechanism enabling three positions: busbar, isolation, and grounding. CT and PT components can be flexibly installed inside the cabinet.

2. Outgoing Cabinet Scheme

Features a ZFN□-10/630 vacuum load switch, fuse with striker (as an isolating switch), and grounding knife, achieving the same three-position functionality. CT/PT and ZNO arresters can be installed as needed. The system meets the “five-prevention” safety design and ensures IP2X protection with interlocked insulation barriers.

Maintenance and Inspection

Regular maintenance ensures long service life and safety:

1. If damp, dry the insulation parts at 70–80°C for 48 hours before reinstallation.
2. Remove rust or dirt if stored improperly and re-protect the surface.
3. Inspect regularly for:
(1) Vacuum degree of arc chamber;
(2) Contact wear;
(3) Tightness of fasteners;
(4) Mechanical parameters such as travel and overrun;
(5) Flexibility of operation;
(6) Reliability of interlocks;
(7) Cleanliness of all components, especially insulation parts.

Comprehensive Inspection

Perform complete inspection and debugging under the following conditions:

- Once every 12 months for routine maintenance.
- After every 2000 load switch operations.

Storage Requirements

The HXGN□-12 SF6 Ring Main Unit should be stored in a dry, ventilated environment with ambient temperature between -30°C and +40°C.

Key Advantages

✔ Compact and modular design
✔ High safety with “five-prevention” interlocking
✔ Low maintenance and long lifespan
✔ Environmental protection with SF6 insulation
✔ Full compliance with IEC and GB standards

Type description

Performance parameters