Connection of galvanized conduit and cable tray

Galvanized conduit can be connected to a galvanized cable tray using approved fittings and bonding jumpers to ensure both mechanical support and electrical continuity.

Mechanical Connection

To physically connect galvanized conduit to a cable tray, use conduit connectors or clamps approved for tray attachment. The conduit sections should be cut to the required length, deburred, and fitted with galvanized couplings to maintain corrosion resistance. The conduit is then secured to the cable tray or supporting structure using straps, clamps, or locknuts to ensure stability and alignment with the tray layout.

Proper planning of the conduit route and tray layout is essential to avoid interference with other trades and maintain accessibility.

Electrical Bonding and Grounding

Both the conduit and cable tray can serve as equipment grounding conductors (EGC), but care must be taken to maintain electrical continuity. If there is an air gap between the conduit and the tray, a bonding jumper should be installed to connect the conduit to the tray, ensuring that any fault current can safely return to the panel. The size of the bonding jumper should comply with NEC Table 250-122 to handle potential fault currents.

In many installations, the conduit is bonded at the panel or MCC using a bond bushing or locknut, and the tray is bonded to the EGC of the cables it carries. This ensures that both systems are at the same electrical potential.

Installation Best Practices

Inspect materials: Check conduits, trays, and accessories for damage before installation. Follow approved drawings: Adhere strictly to shop drawings and specifications for layout and mounting heights. Secure connections: Use clamps or approved connectors to attach conduits to trays, avoiding loose or unsupported sections.

Verify continuity: After installation, test the electrical continuity of the conduit-tray system to ensure proper grounding. Maintain corrosion protection: Ensure all connections preserve the galvanized coating to prevent rust and degradation. By following these mechanical and electrical practices, the connection between galvanized conduit and cable tray will be both structurally secure and electrically safe, meeting code requirements and ensuring reliable operation of the electrical system.