| Quantity: | |
|---|---|
The Cable Sheath Protection Grounding Box is specifically designed for 35–220 kV high-voltage cable systems. It is used for direct grounding and cross-bonding connection of three-phase cable metal sheaths, effectively protecting the outer sheath insulation from overvoltage damage and significantly improving the operational reliability of power cable lines.
This product accommodates grounding cable conductor cross-sections ranging from 120 mm² to 400 mm². Suitable for both outdoor installation and cable trench applications, it adapts well to a variety of high-voltage cable routing environments, including:
Urban underground cable networks
Substation outgoing sections
Mountainous transmission corridors
| Feature | Description |
|---|---|
| Reliable Cable Sheath Protection | Connects and protects the metal sheath of high-voltage cables, reducing the risk of sheath overvoltage damage during switching, lightning strikes, or fault conditions. |
| Supports Cross-Bonding and Direct Grounding | Supports both cross-bonding interconnection and direct grounding of three-phase cable metal sheaths, optimizing sheath current distribution and reducing circulating currents. |
| Durable Structural Design | Welded high-grade stainless steel enclosure ensures long-term durability in corrosive or humid environments. Insulating components are moisture-resistant. |
| High-Conductivity Copper Grounding Connection | Grounding busbar and terminals made of high-conductivity copper (tin-plated option available for enhanced corrosion resistance) ensure stable grounding performance and low contact resistance. |
| Easy Installation and Maintenance | Bolt-connected internal assemblies allow easy disconnection for testing or fault diagnosis. Front cover opens without special tools for routine inspection. |
| Parameter | Value |
|---|---|
| Voltage Class | 35 kV – 220 kV |
| Grounding Cable Conductor Size | 120 mm² – 400 mm² |
| Connection Type | Direct grounding / Cross-bonding |
| Enclosure Material | High-grade stainless steel (welded) |
| Internal Conductors | High-conductivity copper (tin-plated optional) |
| Protection Core | Zinc oxide (ZnO) varistor – nonlinear resistance element |
| Application | Outdoor installation, cable trench, underground network, substation, mountainous corridor |
| Standards | IEC / GB (compliant) |
The core component of the grounding box is the cable sheath protector, which consists of oxidation-resistant nonlinear resistance elements (typically zinc oxide varistors).
Under normal operating conditions: The resistance element remains in a high-resistance state, effectively isolating the sheath from ground for cross-bonded sections.
During overvoltage events (lightning strikes or switching surges): The resistance element rapidly switches to a low-resistance state, clamping the voltage across the protector within a safe range.
This mechanism helps effectively protect the outer sheath insulation of the cable, preventing damage caused by overvoltage and extending the service life of the high-voltage cable system.
| Application | Description |
|---|---|
| Urban Underground Cable Networks | Protects high-voltage cable sheaths in dense city power grids. |
| Substation Outgoing Sections | Ensures reliable grounding and overvoltage protection at substation exits. |
| Mountainous Transmission Corridors | Durable design suitable for harsh terrain and outdoor environments. |
| Long-Distance Transmission Lines | Reduces circulating currents and minimizes sheath losses. |
| Benefit | Description |
|---|---|
| Overvoltage Protection | Zinc oxide varistor provides fast response and reliable clamping. |
| Flexible Grounding Modes | Supports both direct grounding and cross-bonding for optimal sheath current control. |
| Sturdy Construction | Stainless steel housing ensures long service life in outdoor and corrosive environments. |
| Low Contact Resistance | High-conductivity copper terminals ensure stable grounding performance. |
| Easy Maintenance | Bolt-connected internal assembly and tool-free front cover access simplify routine inspection. |
| Item | Specification |
|---|---|
| Application Voltage Class | 35–220kV high-voltage cable systems |
| Grounding Cable Conductor Cross-Section | 120–400 mm² |
| Ambient Temperature | -40°C to +40°C |
| Altitude | Not exceeding 1,800 meters |
| Power Frequency | 50 Hz |
| Installation Environment | Outdoor or cable trench |
