I. Product definition
Cable branch box (Cable Distribution Box) is a special equipment used to realize cable multi-branch connection in power cable network, which mainly completes the functions of cable transfer, branch and power distribution. The equipment has the characteristics of complete insulation, complete sealing, dustproof and waterproof, and is widely used in medium and low voltage cable networks in urban distribution networks, industrial parks, commercial centers and other places.
Second, product classification
1. According to the voltage level
Low voltage cable branch box: 0.4kV grade.
Medium voltage cable branch box: 10kV/20kV/35kV.
2. According to the structural form
Ordinary type: basic cable connection function
Intelligent: integrated monitoring, fault indication and other functions.
Explosion-proof type: suitable for petrochemical and other special places.
Landscape type: appearance design in harmony with urban environment
3. According to the insulating medium
Air insulation type
SF6 gas insulated type
Solid insulation type
Third, the product structure composition
1. Main components
Box: stainless steel or SMC composite material, with protection grade of IP54/IP65.
Cable connector: totally insulated and touchable/untouchable.
Branch connector: T-type/elbow-type/straight-through type
Grounding device: a perfect safety grounding system.
Intelligent unit (optional): fault indicator, temperature monitoring, etc.
2. Typical configuration
Wire feed unit: 1-2 times
Outlet unit: 2-8 times
Reserved extension interface
Fourth, the technical characteristics
1. Safety performance
Fully insulated and fully sealed structure
Anti-condensation and anti-corrosion design
Anti-misoperation mechanical interlock
Reliable grounding protection system
2. Intelligent features
On-line monitoring of cable joint temperature
Fault automatic location indication
Wireless data transmission function
Remote monitoring interface
3. Environmental adaptability
Wide temperature operation: -40℃-+70℃
Anti-ultraviolet aging
Salt spray corrosion prevention (special for coastal areas)
V. Typical application scenarios
Typical configuration of application characteristics in application field
10kV 4-in and 6-out intelligent power supply node of urban distribution network ring network
0.4kV 2-in 4-out common terminal distribution in residential quarters
Large-capacity multi-branch 20kV 2-in 8-out explosion-proof type in industrial park
Beautiful and compact commercial center, 10kV landscape concealed installation.
Anti-vibration design of rail transit 35kV reinforced type
Six, selection guide
1. Selection of key parameters
Rated current: 400A/630A/1250A.
Short circuit tolerance: 20ka/25ka/31.5ka.
Protection grade: IP54 (outdoor) /IP65 (special environment)
Cable section: adapt to 240mm2/400mm2/630mm2.
2. Special requirements
Coastal area: C4/C5 anticorrosion grade
Cold region: low-temperature materials
Dense area: miniaturization design
Seven, installation and maintenance points
1. Installation requirements
The foundation is above 300mm above the ground.
800mm operation space shall be reserved around.
The bending radius of the cable meets the specifications.
2. Maintenance cycle
Comprehensive inspection once a year.
Infrared temperature measurement once every quarter.
Monthly data collection of smart devices
VIII. Technical parameters
Typical project parameters
The rated voltage is 12/24/40.5kv.
Rated current 630A
Power frequency withstand voltage 42kV/1min
Lightning impulse withstand voltage 75kV
Protection grade IP54
Service life ≥30 years
IX. Development trend
Intelligent upgrade: integrating more sensors and communication functions
Application of environmental protection materials: SF6-free environmental protection products.
Modular design: quick installation and replacement
Digital Twin Technology: Realizing Life Cycle Management
As the key equipment of distribution network, cable branch box is developing in the direction of being smarter, more reliable and more environmentally friendly, providing safe and efficient cable connection solutions for modern power systems.
