Galvanized cable trays are not conductive

Galvanized cable trays are metallic and inherently conductive, but their galvanization does not prevent them from conducting electricity; earthing or bonding depends on their role in the electrical system.Conductivity and GalvanizationGalvanized cable trays are made of steel coated with zinc to protect against corrosion. The zinc layer forms a protective oxide or carbonate patina, which slows corrosion but does not make the tray non-conductive. Electrical continuity is maintained through the metal, and the tray can conduct electricity if it is part of a fault current path or connected to other metallic components .Earthing and Bonding ConsiderationsWhether a galvanized tray must be earthed or bonded depends on its classification:Exposed-Conductive-Part: If the tray itself is intended to carry fault currents (e.g., used as a protective conductor), it must be earthed to allow fault current to operate protective devices .Carrying Metallic-Sheathed Cables: If the tray only supports cables with metallic sheaths (like MICC cables), the sheath provides the fault path, and the tray does not require earthing. Earthing in this case could create unnecessary touch voltages .Carrying Non-Metallic Sheathed Cables: The tray is not an exposed-conductive-part, and earthing is generally not required. Bonding may only be needed if the tray introduces an external Earth potential, making it an extraneous-conductive-part .Practical ImplicationsGalvanized trays remain conductive despite the zinc coating. The decision to earth or bond them should be based on:The type of cables they carryWhether they serve as a protective conductorWhether they could introduce external Earth potential In most standard installations with insulated or metallic-sheathed cables, galvanized trays do not need to be earthed, but they remain electrically conductive and capable of carrying current if connected in a fault path .