Are you searching for reliable, intelligent, and cost-effective cable distribution solutions for your power network? Welcome to Jinhand Electric Co., Ltd., a leading China manufacturer, supplier, and factory with over a decade of expertise in designing and producing high-performance Cable Branch Boxes and intelligent switching stations. As a critical node in modern medium-voltage distribution systems, our Branch Boxes are engineered to enhance grid reliability, simplify maintenance, and enable smart grid functionalities for utilities, industrial complexes, urban developments, and renewable energy projects worldwide. With Jinhand, you gain a partner committed to innovation, quality, and comprehensive support from concept to commissioning.
A Cable Branch Box, also referred to as a cable distribution cabinet, cable junction box, or ring main unit (RMU) enclosure, serves as a strategic connection and control point in medium-voltage (typically 6-24kV) underground cable networks. Its core functions include:
Splitting a main power cable feed into multiple outgoing feeders to supply different areas or loads.
Providing points to isolate sections of the network for safe maintenance, fault location, and repair without affecting the entire system.
Housing switching devices (load switches, circuit breakers), fuses, and protection relays to control power flow and interrupt fault currents.
Integrating current transformers (CTs), voltage transformers (VTs), and intelligent electronic devices (IEDs) for data acquisition, energy metering, and condition monitoring.
Jinhand is your ideal partner because we approach the Branch Box not just as a metal enclosure, but as a customizable, intelligent node for your distribution network. As a direct manufacturer and factory in China, we control the entire production process—from precision sheet metal fabrication and high-quality component sourcing to advanced assembly and rigorous testing. This vertical integration allows us to offer superior products, competitive pricing, and the flexibility to tailor solutions to your exact specifications, whether you need a simple compact box or a fully-featured outdoor intelligent switching station.
Jinhand's comprehensive Cable Branch Box portfolio is designed to address diverse application scenarios. Understanding the categories is the first step to making an informed choice:
These are the fundamental, highly reliable units for basic cable tapping, splicing, and connection. They focus on safety, durability, and ease of access.
a. Advanced Insulation: May use air insulation, solid insulation shrouds, or encapsulated busbars to ensure safety and compactness.
b. Ergonomic Access: Bidirectional or multi-door designs with wide opening angles provide unobstructed access for cable terminations and inspections.
c. Modular Connection Systems: Utilize standardized, bolted connector systems (e.g., T-connectors, elbow connectors) rated for 200A or 630A, ensuring reliable and repeatable connections.
d. Clear Phasing & Labeling: Internal layout is designed for clear phase segregation (A, B, C) and includes permanent, legible labeling for error-free operation.
Ideal Application Scenarios
Cable branching points in urban residential districts.
Feeders from a main substation to multiple factory buildings within an industrial park.
Connection points in wind or solar farm collection systems.
Any application requiring a robust, maintenance-friendly, and space-efficient connection node.
(1) Core Concept
These are advanced, turnkey solutions that integrate primary switchgear, protection, control, and communication into a single, weatherproof, prefabricated enclosure. They represent the evolution of the traditional Branch Box into a smart grid asset.
(2) In-Depth Features
a. Fully Integrated Primary System:Can include load switches, SF6 or vacuum circuit breakers, fuse-switch combinations, transformers, and busbars in a compact arrangement.
b. Comprehensive Secondary System:Factory-installed and wired control cabinet containing protection relays, PLCs, communication processors (FTU/DTU), metering devices, and SCADA interfaces.
c. Civil Engineering-Free Design:Prefabricated concrete base or compact steel skid allows for rapid installation, dramatically reducing on-site construction time and cost.
d. Smart Grid Ready:Equipped with IEC 61850 compliant IEDs, supporting remote control, fault detection, isolation, and service restoration (FDIR), load monitoring, and data logging.
Ideal Application Scenarios:
Ring main units (RMU) in urban secondary distribution networks.
Compact substations for commercial complexes, hospitals, or data centers.
Temporary or permanent power supply for construction sites, events, or mining operations.
Grid automation projects requiring remote monitoring and control.
(1) Core Concept
Utilizing SF6 or eco-friendly gas as the insulation and arc-quenching medium, these units offer the ultimate in compactness, reliability, and environmental immunity. All live parts are sealed in a pressurized stainless-steel tank.
(2) Key Advantage
Extremely small footprint, completely maintenance-free for the primary system, ideal for flood-prone areas, coastal sites, or heavily polluted environments.
Jinhand's Offering
While not explicitly detailed in the provided file, as a leading High Voltage Switchgear manufacturer, Jinhand possesses the technology to supply GIS-type compact RMUs, which are a premium variant of the intelligent Branch Box.
Selecting the right Branch Box is a multi-faceted decision. Follow this comprehensive guide, and leverage Jinhand's complimentary engineering consultation.
(1) System Voltage:Confirm nominal voltage (e.g., 12kV, 24kV). Jinhand's standard range covers 12kV.
(2) Normal & Maximum Load Current:Calculate based on connected load and diversity. Our products support currents from 200A to 630A for feeders.
(3) Fault Level Analysis:Determine the prospective short-circuit current at the installation point. This dictates the required short-time withstand current (Icw) and making/breaking capacity.
(1) Switching & Protection Needs
Simple Connection Only?Choose a basic insulated Branch Box (DFW type).
(2) Need Local Isolation? Specify a box with load break switches.
(3) Need Fault Interruption & Protection?Opt for an intelligent station with circuit breakers or fuse-switch combinations (XGW type).
(1) Space Constraints:Precisely measure the available footprint.
(2) Ambient Temperature: Standard range is -25°C to +40°C; wider ranges available.
(3) Altitude: Standard design for ≤2000m. Derating or special design needed for higher altitudes.
(1) Monitoring: Do you need remote reading of voltage, current, power, temperature?
(2) Control: Do you need remote open/close commands?
(3) Automation: Do you want feeder automation (FA) for fault isolation and restoration?
(4) Communication:Specify required protocols: IEC 61850, DNP3.0, Modbus RTU/TCP, IEC 60870-5-101/104.
Quality is quantified. Here are the detailed specifications that define the performance and reliability of our products.
| Parameter Category | Detail | DFW-12 Branch Box | XGW-12 Intelligent Station | Unit | Remarks/Standard |
| General | Rated Voltage | 12 | 12 | kV |
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| Rated Frequency | 50 | 50 | Hz |
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| Rated Normal Current | 630 | 630 (LS),200(CB Combi) | A | Per feeder | |
| Short-Circuit Performance | Short-Time Withstand Current (Icw) | 20(3s)-Thermal | 20(3s) | KA,s |
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| Peak Withstand Current (Ipk) | 50 | 50/63 | kA |
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| Rated Short-Circuit Breaking Current | N/A | 20(for CB) | kA | For circuit breaker unit | |
| Insulation Level | Power Freq.Withstand (1min) | 42 | 42(Ph-G)48(Break) | kV | Dry,RMS |
| Lightning Impulse Withstand | 105 | 75(Ph-G),85(Break) | kV | 1.2/50 μs wave,peak | |
| External Creepage Distance | ≥20 | ≥20 | mm/kV | Against pollution | |
| Mechanical &Operational | Mechanical Life(Operations) | N/A for box itself | ≥2000(for switches) | times |
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| Operating Mechanism | Manual | Manual/Electric(Optional) |
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| Interlocking | Mechanical | Mechanical&Electrical |
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"Five-Prevention" | |
| Enclosure &Environment | Protection Degree(IP Code) | IP33 | IP4X |
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IEC 60529 |
| Material | Galvanized Steel/Stainless Steel | Stainless Steel/Coated Steel |
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| Operating Temperature | -25℃ to+40℃ | -30℃ to+40℃ | ℃ |
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| Smart Features | Communicaion Protocol | N/A | IEC 61850,DNP3.0,Modbus |
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Optional on XGW |
| Integrated Devices | N/A | FTU/RTU,Protection Relay,Metering |
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(1) Type Test Compliance: Our products are designed to meet GB/T 11022, GB 3906 (for metal-enclosed), and referenced IEC 62271 series standards.
(2) Sealed for Life (GIS option): For gas-insulated modules, the annual leak rate is guaranteed < 0.5% per year, with a service interval exceeding 30 years.
(3) Corrosion Resistance: Outdoor enclosures undergo ≥1000 hours of salt spray testing (ASTM B117) to ensure longevity in harsh environments.
We are a solutions partner, not just a product vendor. Our services include:
Free load flow and short-circuit studies, single-line diagram (SLD) review, and complete bill of materials (BOM) preparation.
We can provide 3D models of our equipment for your civil and electrical design integration.
You or your representative can visit our factory in China to witness routine tests (power frequency withstand, mechanical operation, protection relay functional tests) and review quality control processes.
Supplied with every order: General arrangement drawings, wiring diagrams, instruction manuals, test certificates, and material certificates for major components.
We can dispatch experienced engineers to your site for installation supervision, cable termination guidance, secondary wiring check, and functional commissioning.
Tailored training sessions for your operations and maintenance staff, covering equipment overview, normal/abnormal operations, routine maintenance, and basic troubleshooting.
We maintain a strategic inventory of common spare parts and offer a transparent supply channel for long-term support.
Air-Insulated (AIS): Live parts are separated by air gaps and solid insulation (e.g., epoxy). It requires more internal space for clearance but is generally easier to inspect and has lower initial cost. Gas-Insulated (GIS): Live parts are enclosed in a sealed tank filled with SF6 or similar gas, which has excellent insulating and arc-quenching properties. It is extremely compact, maintenance-free for the primary system, and immune to environmental contamination. The choice depends on space, environment, and lifecycle cost preferences.
We employ several measures: 1) Precision Machining: Connector pads and busbars are accurately machined for flatness. 2) Specified Torque: We provide detailed torque specifications for all bolted connections. 3) Contact Paste: We recommend and can supply high-quality electrical contact paste to reduce resistance and prevent oxidation. 4) Thermal Imaging Check: During our FAT, we can perform a thermal imaging scan under load to verify uniform temperature rise across connections.
