33kV Ring Main Unit

Product Overview

The 33kV gas-insulated ring main unit is a compact gas-insulated power distribution complete device developed for medium and high-voltage distribution networks, large industrial parks, new energy bases, urban power grid main networks and power grid upgrading and reconstruction projects. It is suitable for three-phase AC 50Hz, rated voltage 33kV power distribution systems, mainly undertaking core functions such as power distribution, control, protection, monitoring and rapid fault isolation and handling. It is the core equipment for building a safe, efficient, intelligent and energy-saving medium and high-voltage distribution network.

With SF₆ gas insulation as the core technology, the product integrates core modules such as three-position load switch, earthing switch, fuse, intelligent measurement and control unit and complete five-prevention interlocking. It adopts a fully sealed and fully insulated structural design, featuring obvious advantages such as safety and reliability, small footprint, convenient installation, high intelligence, strong environmental adaptability and low operation and maintenance costs. It is widely used in large industrial parks, new energy power stations (photovoltaic, wind power), urban distribution network main lines, rail transit hubs, mines and oil fields, high-rise buildings and overseas medium and high-voltage power distribution scenarios, fully meeting the high-end needs of distribution network automation, digitalization and intelligent construction.

The product strictly complies with national standards and international specifications such as GB/T 3906-2020, GB/T 11022-2020 and IEC 62271, and has passed authoritative type tests, CCC certification and power grid access certification. It implements strict full-process quality control, with stable performance and reliable quality, and can operate stably for a long time.

Operating Environment

1.  Ambient temperature: Normally applicable to -25℃～+40℃, the 24-hour average temperature does not exceed +35℃; it can be customized to adapt to extreme high and low temperature environments of -40℃～+55℃, meeting the operation needs of severe cold and extremely hot areas.

2. Altitude: Normally applicable to altitude ≤2000m, and can be customized to 4500m for special working conditions, adapting to plateau area power distribution scenarios.

3.  Relative humidity: Daily average ≤95%, monthly average ≤90%; equipped with an intelligent anti-condensation temperature control system, which automatically adjusts the humidity in the cabinet, eliminating equipment faults caused by moisture and condensation.

4.  Pollution class: Standard Class Ⅲ, Class Ⅳ anti-pollution, anti-salt spray and anti-corrosion customization schemes are available, adapting to harsh polluted environments such as coastal areas, chemical industry and mines.

5.   Installation conditions: The installation inclination angle is ≤5° with the vertical plane, no fire, explosion, strong vibration, corrosive gas or dust pollution, and it can flexibly adapt to conventional and complex indoor and outdoor operating environments.

Technical Parameters

Product Features

1.  Fully sealed and fully insulated, long-term maintenance-free

The core conductive circuit and switch components are sealed in a stainless steel gas chamber filled with high-purity SF₆ insulating gas, and the live parts are completely shielded, not affected by external environments such as dust, moisture, rain and snow, and pollution. The annual gas leakage rate of the gas chamber is ≤0.1%, enabling long-term maintenance-free operation for more than 15 years, greatly reducing operation and maintenance costs and labor input.

2. Complete five-prevention interlocking, safe operation without worry

Equipped with a forced mechanical interlocking device, it strictly realizes five major safety protections — preventing mis-closing/opening of the switch, preventing operation with load, preventing closing to ground when live, preventing power transmission with the earthing switch closed, and preventing entering the live compartment. It comprehensively ensures the safety of operators and equipment operation and eliminates safety accidents.

3. Modular design, flexible configuration and adaptation

Adopting standardized unit module design, it can freely combine functional units such as ring inlet, ring outlet, feeder, PT, metering and circuit breaker, supporting various wiring modes such as single-ring, double-ring, radial and dual-power supply. The circuit expansion is convenient and the interchangeability is strong, which can accurately adapt to the needs of different medium and high-voltage power distribution scenarios.

4.  High-protection structure, adaptable to complex environments

The cabinet is made of high-quality anti-corrosion and anti-rust plates, matched with a double-layer top cover and water guide structure, featuring excellent waterproof, sun-proof, anti-corrosion and impact resistance performance. The overall protection level reaches IP43–IP54, with high mechanical strength, which can operate stably in harsh indoor and outdoor environments, with a service life of more than 20 years.

5.  Intelligent integration, supporting distribution network automation

It can be integrated with an intelligent terminal unit to realize functions such as telemetry, remote signaling, remote control, fault detection and location, and automatic fault isolation. It supports various communication methods such as 4G/5G, Ethernet, power carrier and wireless private network, seamlessly connecting with the distribution automation platform, improving power supply reliability and management efficiency, and adapting to the development trend of digital distribution networks.

6.  Efficient installation and deployment, saving space costs

The overall pre-installation and commissioning are completed in the factory, and only foundation fixing and cable connection are needed on site, with short construction period and high efficiency; the equipment has a compact structure and small footprint, saving more than 30% of space compared with traditional switchgear, suitable for rapid commissioning in scenarios such as narrow urban spaces, indoor power distribution rooms, outdoor box-type substations, plateau and overseas simple stations.

Core Advantages

1.   Mature and stable technology: With years of experience in R&D and manufacturing of medium and high-voltage power distribution equipment, core components are selected from high-quality domestic and foreign brands, with strict full-process quality control. The products have passed power grid access certification, with high operational reliability, and can adapt to the harsh operation requirements of 33kV medium and high-voltage power distribution systems.

2.   Leading intelligence level: Supports high-end functions such as primary and secondary fusion, remote monitoring, status visualization, line loss monitoring and fault self-healing, which can realize real-time equipment status monitoring and remote operation and maintenance, adapting to the development trend of digital and intelligent distribution networks.

3.  Improved customized services: According to the actual needs of users, it can customize the number of circuits, operation mode, protection level, communication scheme, cabinet size and color, accurately matching the needs of special working conditions such as plateau, coastal areas, chemical industry and overseas projects.

4.   Full life cycle guarantee: Provide one-stop services such as scheme design, production and manufacturing, installation guidance, commissioning training, operation and maintenance after-sales, with a professional technical team following up the whole process to ensure long-term stable operation of the equipment and solve users' worries.

5.   Fast and efficient delivery: Adopting standardized mass production mode, with sufficient inventory and short delivery cycle, it can quickly respond to the delivery needs of urgent orders, large-scale centralized procurement and overseas projects, ensuring the smooth progress of the project.

Ordering Instructions

Please provide the following information when ordering to facilitate our company to provide the optimal solution, reasonable quotation and reliable delivery:

1.  System voltage level, circuit configuration and main wiring diagram;

2.  Rated current, short-circuit current, type of operating mechanism (manual/electric);

3.  Intelligent function requirements, communication mode and docking protocol;

4.   Installation environment parameters (temperature, altitude, pollution class, etc.), protection level, cabinet size and color requirements.