Wire mesh cable trays are widely used in commercial offices, industrial facilities, data centers, and smart building infrastructure because they provide unmatched flexibility, excellent airflow, and fast, adaptable installation. Their open-grid design makes it easy to route, add, or modify cabling as systems evolve—an essential advantage in environments where technology frequently changes. In addition, the open structure promotes natural heat dissipation, which is especially important in high-density installations supporting PoE lighting, IP cameras, automation controls, and structured cabling systems. 

However, while wire mesh trays offer mechanical and thermal advantages, proper grounding and bonding are critical to ensure electrical safety, NEC compliance, and long-term system reliability. Metallic cable tray systems can become energized under fault conditions, making an effective grounding path essential to protect personnel and equipment. Without proper bonding at splice points and secure connections to the building grounding system, the tray may not provide a continuous fault current path creating potential shock hazards, equipment malfunction, or failed inspections. 

Key Takeaways 

  • Grounding and bonding are essential for safety. They protect personnel and equipment by providing a safe path for fault current. 
  • NEC Article 392 governs cable tray grounding requirements. Metallic wire mesh trays must be electrically continuous and properly bonded. 
  • Electrical continuity is critical. All tray sections and fittings must maintain a conductive connection across the entire system. 
  • Bonding at splice points is mandatory. Use bonding jumpers where mechanical connections alone do not ensure continuity. 
  • Proper grounding conductor sizing matters. Follow NEC tables to ensure conductors can safely carry potential fault current. 
  • A secure connection to the building grounding electrode system is required. This completes the effective fault current path. 

Why Grounding & Bonding Matter 

Improper grounding in metallic cable tray systems can lead to serious safety and operational risks. Without a reliable grounding path, installations may face shock hazards to personnel, equipment damage from fault currents, arc faults, increased fire risk, and ultimately failed electrical inspections. Even a single discontinuity in the grounding path can compromise the entire system’s safety performance. 

Grounding ensures that any fault current has a low-resistance, safe path to earth, allowing protective devices such as breakers or fuses to trip quickly and clear the fault. Bonding, on the other hand, ensures that all metallic components, tray sections, fittings, supports, and splices remain electrically continuous. Together, grounding and bonding create a complete protective system that reduces risk and maintains code compliance. 

Understanding NEC Requirements for Cable Tray Grounding 

NEC Article 392 clearly outlines the grounding and bonding requirements for cable tray systems, establishing the standards necessary to ensure electrical safety and code compliance. Installers must verify electrical continuity across all tray sections so that the entire system functions as a continuous conductive path. This includes bonding at all splice points to eliminate gaps in conductivity and using properly sized grounding conductors in accordance with NEC tables. Additionally, cable tray systems must be securely connected to the building grounding electrode system to provide an effective fault current path. 

Bonding Wire Mesh Cable Trays Correctly 

Wire mesh trays are typically constructed from steel and may include powder coating. Since coatings can reduce conductivity at connection points, installers must ensure bonding integrity. 

Best Practices Include: 

  • Using manufacturer-approved splice connectors 
  • Tightening hardware to the recommended torque 
  • Scraping coating at bonding points when required 
  • Installing bonding jumpers if continuity is questionable 

The goal is to create a continuous electrical pathway throughout the entire tray run. 

Grounding Conductor Sizing 

Grounding conductor size depends on: 

  • Circuit rating 
  • Overcurrent protection devices 
  • NEC grounding tables 

When trays serve as equipment grounding conductors (EGC), they must meet NEC minimum cross-sectional area requirements. 

Installers should verify: 

  • Tray material thickness 
  • Width compliance 
  • Fault current capacity 

If trays do not qualify as EGCs, a separate grounding conductor must be installed. 

Cable Types & Grounding Considerations 

Proper grounding performance is also influenced by the types of cables installed within the tray system. Different cable categories carry varying voltage levels and fault current potential, which directly impacts grounding and bonding considerations. Ensuring compatibility between the cable type and the tray system helps maintain safety, compliance, and long-term reliability. 

Power cables typically carry higher voltages and greater fault current potential than low-voltage data or communication cables. Because of this, proper bonding and grounding of metallic cable trays becomes even more critical. A well-bonded tray system helps provide an effective fault current path, allowing protective devices to trip quickly and minimize damage during a fault condition. 

Common Grounding & Bonding Mistakes 

  • Assuming mechanical connection equals electrical continuity 
  • Ignoring coating interference at splice points 
  • Failing to size grounding conductors correctly 
  • Overlooking bonding at tray transitions 
  • Not verifying continuity with a meter 

Always test continuity before energizing systems. 

Why Mesh Cable Trays Support Safer Installations 

Wire mesh cable trays offer several advantages that make them a preferred solution in modern cable management systems. Their open-grid structure provides strong mechanical support for a wide range of cable types while maintaining flexibility for routing and future modifications. The design also allows easy visual inspection of grounding and bonding connections, making it simpler to verify electrical continuity and maintain NEC compliance. 

 In addition, improved airflow through the mesh structure helps dissipate heat, reducing cable temperature buildup, especially important in high-density installations and PoE applications. The modular nature of wire mesh trays further simplifies bonding continuity across sections, supporting a safer and more reliable installation. 

Because of these benefits, wire mesh trays are ideal for commercial office networks, industrial automation environments, smart building infrastructure, and data center pathways where scalability, safety, and performance are critical. 

ShowMeCables ensures electrical systems are safe, reliable, and code compliant. Our grounding and bonding solutions protect personnel and equipment by providing a secure path for fault current. We follow NEC standards, maintain full electrical continuity in all cable trays, and use proper bonding and conductor sizing to guarantee safety. Every system is securely connected to the building’s grounding electrode, completing an effective fault current path. 

At ShowMeCables, safety and compliance are built into every connection. 

 

ShowMeCables offers a full range of network connectivity and infrastructure solutions for small and medium-sized businesses. In addition, our customer-focused approach includes a same-day shipping policy and U.S.-based customer service support.  Questions? Please call us at +1 (866) 545-8420, email us or visit our contact page.   

 

Frequently Asked Questions 

Do wire mesh cable trays need to be grounded? 

Yes. Metallic trays must be bonded and connected to the building's grounding system. 

Can cable trays serve as equipment grounding conductors? 

Yes, if they meet the NEC cross-sectional area and installation requirements. 

Do fiber optic cables require grounding? 

Fiber cables are non-conductive, but the tray system must still be grounded.