Issues with cable trays
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This post was last edited by zyzs on 2011-5-25 at 13:15. I would like to ask the experts: The design drawings state that the protective grounding of field instruments, instrument cable trays, instrument junction boxes, and field instrument panels is connected directly to the plant’s electrical grounding grid through the cable trays. How should this sentence be understood? Generally, for the grounding of cable trays, the grounding wire is run throughout the entire length of the tray. Upon seeing this sentence, I’m not sure what to do regarding the grounding of the cable tray at that time. Dear experts, please take into account the statements in the design drawings and discuss how to ground the cable tray.
The grounding flat bar is connected directly to the cable tray, or a single-strand copper wire is used to connect to the electrical grounding grid.
Reply to 2# zhj26: Can it be understood in this way that the wiring is laid continuously within the cable tray, and then every 30-50 meters, flat iron or other types of grounding wires are used to connect to the plant’s overall grounding network.
Flat iron is used for laying in cable trays, typically those used for power cables; for instrument cable trays, yellow-green wires are used for bridging at the connections of the tray sections, or galvanized woven wires are employed for such connections, with a grounding wire being used to connect everything to the main grounding circuit