DFWK-12 Series Outdoor Ring Main Unit Product Introduction

1. Product Brief Introduction

The DFWK-12 series outdoor ring main unit is developed by our company adopting advanced foreign technologies and combining with the actual situation of power grid network reconstruction in various regions and urban distribution network cabling in China. It is an outdoor SF6 ring main unit with first-class level in the industry.

The DFWK-12 series outdoor ring main unit is an SF6 fully sealed fully insulated ring network switchgear derived from the HRM-12/24 series of our company. The switchgear has the characteristics of modularization, expandability, full insulation, full sealing, full safety, maintenance-free, equal potential connection of phase and ground, etc. It is suitable for industrial parks, residential areas, streets, airports, various buildings and other places with any 12KV, 24KV indoor and outdoor ring network power supply requirements, and can be equipped with distribution automation to realize the intellectualization of ring network and make the power grid more stable and intelligent.

2. Model Meaning & Explanation

The coding of the product model contains the core structural characteristics and parameter information of the ring main unit. The specific meaning of each part of the model is as follows:

DFWK - 12 / H - □

3. Normal Operating Conditions

• Ambient temperature: Maximum temperature +50℃, minimum temperature -40℃, maximum daily average temperature not exceeding 35℃;
• Relative humidity: Not more than 95% in monthly average, not more than 90% in daily average;
• Wind speed: Not exceeding 35m/s;
• Pollution degree: Class Ⅲ;
• Ground inclination: Not more than 3 degrees;
• Installation site: Installed in places without fire, explosion or violent vibration, with good ventilation and no corrosive gas;
• Special conditions: When installed at an altitude of more than 1000 meters, it must be specified separately, so that our company can adjust the SF6 pressure during factory inspection;
• If the equipment involves special installation conditions, please consult our company in advance.

4. Product Characteristics

• Safety: All live parts are sealed in SF6 gas tank to realize full sealing and full insulation; The operating mechanism of the switch adopts fully enclosed mechanical transmission to avoid misoperation; The incoming and outgoing line terminals adopt fully insulated full mechanical connection mode to maximize the guarantee of personal safety; The cabinet body has passed the pressure rise test and internal combustion test of authoritative institutions under the pressure meeting the five-level earthquake resistance standard; An explosion-proof pressure relief device is set at the bottom of the cabinet body, which has passed the internal combustion test of authoritative institutions under the normal operation pressure.
• Flexibility: Flexible incoming and outgoing line modes, can realize upper and lower incoming (outgoing) lines; Combined mode is flexible, which can realize arbitrary combination of single units without limit expansion; Adopt indoor and outdoor busbar expansion mode, which meets the requirements of practicality, economy and aesthetics; The design scheme is flexible and can be modified according to on-site requirements.
• Structural Standardization: All unit modules have the same size (except for module replacement), compactness without affecting the convenience of construction.
• Economy: No foundation, small floor area, high cost performance, service life exceeding 30 years.
• Applicability: The shell is made of stainless steel plate and processed by full-automatic TIG seal welding, with protection grade up to IP67. It can be installed in places with humidity, much dust, salt mist, mine and any air pollution without special protection measures.
• Intelligentization: It can be equipped with intelligent electric operating device and distribution automation terminal device to realize intelligent switchgear with "four connections" function, meeting all requirements of smart grid for such equipment.

5. Product Reference Standards

• GB 1984-2003: High-voltage alternating current circuit breakers
• GB 1985-2004: High-voltage alternating current isolating switches and earthing switches
• GB 3804-2004: 3.6kV~40.5kV high-voltage alternating current load switches (IEC60265)
• GB 3906-2006: AC high-voltage switchgear and control gear for rated voltages above 1kV up to 52kV (IEC 60694)
• GB 16926-2009: AC high-voltage switchgear and control gear - Synthetic testing (IEC 62271-102)
• GB/T11022-2011: Common specifications for high-voltage switchgear and control gear standards (IEC 60694)
• GB/T4208-2017: Degrees of protection provided by enclosures (IP Code) (IEC 60529)
• DL/T404-2017: Technical specification for 3.6kV～40.5kV AC metal-enclosed switchgear and controlgear
• Q/CSG 120001-2016: Technical Guidelines for Urban and Rural Power Distribution Network of China Southern Power Grid
• National Grid Material Purchasing Standard - 12KV, 24KV Ring Network Interconnection Technical Specification Product Reference Standard

7. Product Structure

• ① Outdoor ring main unit shell: The outer shell is made of 2.0mm thick stainless steel (can be customized with SMC according to user requirements), with waterproof and dustproof design, door interlock with waterproof level IP65, and the door opening method meets the requirements of outdoor environment.
• ② Air pressure gauge: Used for real-time monitoring of SF6 gas pressure in the gas tank, and can give an alarm when the pressure is too high or too low.
• ③ Switch unit gas tank: The tank body is made of 3.0mm thick stainless steel, processed by full-automatic argon arc welding, with internal SF6 gas pressure up to IP67 protection grade, and the gas path passes through high vacuum leak detection to ensure the air tightness of the equipment, and dry air filling ensures the sealing of the tank body.
• ④ Switch cabinet: Adopts three-position load break switch with SF6 gas insulation, high operation reliability.
• ⑤ Communication control cabinet: Equipped with optical transceiver, optical fiber terminal and other communication equipment.
• ⑥ Fault indicator: Used to detect the short circuit and grounding faults of the line, and provide the basis for future distribution automation.
• ⑦ Earthing switch: Used for maintenance.
• ⑧ Observation window: Used for observing the operation status inside the cabinet, providing great convenience for operation and maintenance.
• ⑨ Live display: Used to indicate whether the circuit is live, and used with special supporting accessories.
• ⑩ PT and automation cabinet: Used for installing PT, distribution automation terminal device, etc., with fully sealed and fully insulated cable joints for connection.

8. Main Accessories

Cabinet Body: The outdoor ring main unit shell is designed according to outdoor structure, and the cabinet material can be selected as stainless steel plate, SMC or GRC with surface spray treatment according to customer needs, with sufficient mechanical strength; The cabinet body is provided with a seamless door for better sealing, fixed on a sealed sandwich double-layer base plate with a vent for natural ventilation, heat insulation and heat dissipation; Rainproof door lock, with limit pull hook when opening the door for easy operation, preventing small animals and gas from entering the cabinet body; The appearance and color of the cabinet body can be customized according to user needs, with beautiful appearance and coordinated with the surrounding environment.

Switch Unit: The switch unit adopted by DFVK series outdoor ring main unit is our company's HRM16 fully sealed and fully insulated ring network switch equipment, which has the advantages of modularization, unlimited free expansion, etc. The functions of each functional unit are as follows:

• C Unit: Load break switch + fuse unit, mainly used for connection, branching, sectioning and control of incoming and outgoing lines of 12KV and 24KV distribution network;
• F Unit: Vacuum circuit breaker unit, which can be used alone for connection, branching, sectioning and control of incoming and outgoing lines of 12KV and 24KV distribution network lines, and can also be used for control and protection of large-capacity distribution transformers;
• V Unit: Vacuum circuit breaker unit with microcomputer protection, which can realize overcurrent protection function;
• D Unit: Cable inlet and outlet unit of non-load break switch, used for connecting incoming and outgoing cables with busbar in the cabinet;
• M Unit: Busbar unit, used for connecting between busbar sections or combining with any other cabinet body;
• SV Unit: Metering cabinet, used for metering and other purposes;
• PT Unit: Voltage transformer cabinet, used for installing PT, automation terminal device and backup power supply, etc.

9. Foundation Drawing of Cable Branch Box

10. Ordering Notes

• Provide one-time drawing for product model and special requirements of users;
• Quantity of fault indicators for incoming and outgoing cable branches;
• Sealed bottom plate of incoming and outgoing cable branch pipes;