Grounding Busbar Fixing Spacing: Design Essentials & Industry Insights
In new energy systems, the fixing spacing of grounding busbars is key to both safety and performance. A well-designed layout boosts electrical reliability, ensures mechanical stability, and helps extend system life. This article highlights essential design principles, key influencing factors, and practical tips to support your engineering decisions.
1. Understanding Grounding Busbar Fixing Spacing
Fixing spacing refers to the distance between two adjacent mounting points on a grounding busbar. Though simple in concept, it involves complex considerations such as electrical continuity, mechanical strength, and thermal stability. In new energy systems, typical spacing ranges from 300mm to 600mm, depending on:
Busbar cross-sectional dimensions and rigidity
Expected short-circuit current levels
Ambient temperature fluctuations
Vibration and mechanical stress
Installation space constraints
2. Impact of Fixing Spacing on System Performance
2.1 Electrical Performance
Excessive spacing increases copper busbar deflection during high current flow, especially under short-circuit conditions, leading to:
Higher contact resistance and local overheating
Loose connections and fault risk
Amplified electromagnetic vibration and material fatigue
Tests show that increasing spacing from 300mm to 600mm can increase deflection by 3-5 times and raise contact resistance by 15-25%.
2.2 Mechanical Stability
In complex environments such as storage systems, wind turbines, and photovoltaic stations, improper spacing may trigger resonance, fastener loosening, or fatigue fractures due to vibrations and shocks.
2.3 Thermal Stability
Spacing also affects heat dissipation:
Too close: Limited heat dissipation area; risk of hotspots
Too wide: Uneven heat distribution; inefficient cooling
Ideal spacing ensures even operating temperatures, typically below 90°C.
3. Key Factors Affecting Fixing Spacing
3.1 Busbar Specifications
Larger and heavier copper busbars require tighter spacing to prevent sagging and deformation. For example, a 40mm×4mm busbar can tolerate wider spacing than an 80mm×8mm one.
3.2 Environmental Conditions
Areas with strong vibration or temperature/humidity fluctuations require reduced spacing. In steel mills or seismic zones, tighter fixing enhances stability. In high-humidity areas, optimized spacing aids inspection and corrosion control.
3.3 Electrical Requirements
For applications with strict grounding resistance or EMC requirements (e.g., MRI rooms, data centers), closer spacing ensures low resistance and reduced interference.
4. Design Principles for Fixing Spacing
4.1 Basic Calculation Formula
Preliminary estimate:
L ≤ K × √(Isc × S / Δ)
Where:
K: Material factor (0.8-1.2 for copper)
Isc: Short-circuit current (kA)
S: Cross-sectional area (mm²)
Δ: Maximum allowable deflection (1-2mm)
4.2 Reference Standards
IEC 61439-1
GB/T 5585.1-2018
UL 467
These provide indirect constraints through mechanical and thermal performance requirements.
4.3 Engineering Best Practices
Based on project experience, apply spacing guidelines tailored to application type and environment.
5. Special Considerations for New Energy Applications
5.1 Energy Storage Systems
High charge/discharge current impact
Modular design
Strict thermal control
Design tips:
Ground each module separately
Integrate fixing and connecting points
Allow expansion gaps
5.2 Photovoltaic Systems
High DC voltage (1000V+)
Risk of PID effect
Large daily temperature swings
Solutions:
Uneven segment spacing (closer at ends)
Use elastic brackets for expansion
Add insulation monitoring points
5.3 Wind Power Systems
Continuous vibration
Salt spray corrosion (offshore)
Limited space inside towers
Improvements:
Reduce spacing by 20%
Use anti-loosening fasteners
Add vibration dampers
6. Technological Advances Optimizing Spacing
6.1 Finite Element Analysis
Simulation tools (e.g., ANSYS) help optimize spacing via:
Mechanical stress analysis
Thermal field modeling
Vibration mode prediction
6.2 New Material Use
Nano-composite copper or copper-aluminum hybrids:
Improve strength and allow wider spacing
Reduce weight and mechanical load
Enhance thermal performance
6.3 Smart Monitoring Technology
Sensors embedded in the system can:
Monitor temperature and vibration in real-time
Enable predictive maintenance
Adjust spacing dynamically via smart tension systems
7. Installation and Maintenance Best Practices
7.1 Installation Control
Torque consistency (use calibrated tools)
Treated contact surfaces (e.g., tin-plated, conductive paste)
Precise bracket alignment (<1mm/m)
7.2 Inspection Checklist
Regularly check
Fastener tightness (marking method)
Surface oxidation
Insulation support aging
Abnormal hotspots via thermal imaging
7.3 Common Issues & Solutions
Identify and address problems such as misaligned brackets, loosened joints, and corrosion early to prevent system failure.
8. Fixing Spacing Tolerance Control
Spacing tolerance directly impacts current balance and safety. For parallel electrical busbars, spacing deviation should be ≤5mm. Uneven spacing can lead to overload and overheating. Precision tools (e.g., laser rangefinders) are essential for accurate placement.
At RHI, we combine technical know-how and strict quality standards to deliver stable, efficient grounding systems for demanding new energy applications. Collaborating with expert suppliers early in project design enables optimal solutions and long-term reliability.
Fixing spacing for grounding busbars is not a standalone parameter but part of a complex system requiring balanced electrical, mechanical, thermal, and environmental considerations. As new energy systems evolve, the need for precision and innovation in grounding design grows. Choosing a qualified busbar manufacturer with robust engineering capabilities is key to building safe and durable systems from the ground up.