Product Overview

The FHSS-12 solid-insulated ring main unit switchgear is a new-generation, environmentally friendly, solid-insulated ring main unit independently developed by our company. It consists primarily of three functional units: the V unit (circuit breaker unit), the C unit (load switch unit), and the F unit (combined electrical apparatus unit). Each unit can be used independently or freely expanded. The structure is divided into an intelligent control instrument compartment, an operating mechanism, and the primary circuit section. The instrument compartment can be equipped with microprocessor-based protection (controller) and features a dedicated spring-operated mechanism. The primary circuit section employs the APG automatic gel encapsulation process, completely sealing the disconnector and arc-extinguishing chamber within epoxy resin, with dedicated connectors and busbars for interconnection. The arc-extinguishing chamber is designed using specialized copper-chromium contact materials and R-type longitudinal magnetic field contacts, combined with a fully enclosed primary encapsulation process. As a result, this arc-extinguishing chamber exhibits significantly improved performance in short-circuit current interruption capability, operational stability, electrical life, temperature rise, and insulation level compared with previous designs that utilized copper–aluminum contact materials, cup-shaped longitudinal magnetic field contacts, and incomplete primary encapsulation. The operating mechanism adopts an integrated spring-operated design that works in tandem with the switch, whereby the disconnector and main switch share a single spring-operated mechanism, facilitating easy interlocking while reducing the number of components and eliminating unnecessary transmission stages, thereby enhancing reliability. Additionally, electric operation can be optionally installed according to customer requirements.
Fixed, fully insulated, enclosed switchgear: This type of equipment uses solid insulating materials as the primary insulation medium and integrates conductive connections, disconnect switches, earthing switches, main busbars, branch busbars, and other key conductive circuits—either individually or in combination—and then encapsulates them with solid insulation to form one or more modules that possess complete insulation and full sealing. These modules are designed for specific functions and can be reconfigured or expanded as needed. The three-position mechanism employs a center-spring design, enabling both switching and making/closing of load currents, while also supporting both manual and electric operation.

Terms of Use

● Altitude: ≤2000 m;
● Ambient temperature: -45°C to +65°C;

● The daily average shall not exceed +45°C;

● Relative air humidity: daily average ≤95%, monthly average ≤90%;

● An environment that is not subject to significant contamination by corrosive or flammable gases, etc.;
● Conditions free from fire and explosion hazards, and without frequent severe vibrations.

Implementation Standard

GB 311.1-1997 “Insulation Coordination for Power Transformation and Transmission Equipment”; IEC 62271-1:2007 “High-Voltage Switchgear and Control Gear—Part 1: General Requirements”; IEC 620071-200:2003 “AC Metal-Enclosed Switchgear and Control Gear for Voltages from 1 to 52 kV”; GB 3906-2006 “AC Metal-Enclosed Switchgear and Control Gear for Voltages from 3.6 to 40.5 kV”; GB 3309-1989 “Mechanical Tests of High-Voltage Switchgear at Ambient Temperature”; GB 16926-2009 “High-Voltage AC Vacuum Load Switch–Fuse Combination Apparatus”; GB/T 11022-2011 “Common Technical Requirements for Standards of High-Voltage Switchgear and Control Gear”; GB 1984-2014 “High-Voltage AC Circuit Breakers”; GB 1985-2004 “High-Voltage AC Isolating Switches and Earthing Switches”; GB 3804-2004 “High-Voltage AC Load Switches for Voltages from 3.6 to 40.5 kV”; DL/T 403-2000 “Technical Specifications for Ordering Indoor High-Voltage Vacuum Circuit Breakers for Voltages from 12 to 40.5 kV”; DL/T 404-2007 “AC Metal-Enclosed Switchgear and Control Gear for Voltages from 3.6 to 40.5 kV”; Q/GDW 730-2012 “Technical Specifications for 12-kV Solid-Insulated Ring Main Units”; and 1016006-0010-A0 “General Technical Specification of State Grid Corporation for 12-kV Solid-Insulated Ring Main Units”.

Main Features

● All energized parts are fully insulated and fully enclosed, achieving a fully insulated and fully sealed overall structure with an IP protection rating of up to IP67.

● The primary insulation module features an enhanced interphase design with three-phase separation; its surface can be coated with a conductive layer and grounded to prevent the generation of induced voltages. Partial discharge is unaffected by external contaminants, salt spray, or condensation, ensuring long-term operational stability. This design enables the insulation surface to be safely touched, significantly enhancing safety while achieving complete insulation and maintenance-free operation.
● Fully simulated modular design, uniform electric field distribution, easy circuit expansion, unit adjustment, and primary scheme modification—these features confer advantages in safety, intelligence, environmental friendliness, flexibility, and application in special environments.

Technical Specifications

Standard Cabinet Structure

Core Unit of the Lower Isolation Unshielded Solid Cabinet	Core unit of the isolated shielded solid cabinet
Core Unit of the Lower Isolation Shielded Solid Cabinet

 

Schematic Diagram of Functional Unit Dimensions