Where cable tray systems contain only signal and communication circuits that operate at low energy levels, power grounding per NEC Section 318-7 is not appropriate, but cable tray grounding for lightning protection, noise, and electromagnetic interference is necessary. Power circuit grounding of cable trays is explained in CTI Technical Bulletins, Titles No. It is also covered in NEMA Standard VE-2. The purpose of power grounding (Article 250) is to minimize the damage from wiring or. Cable tray may be used as the Equipment Grounding Conductor (EGC) in any installation where qualified persons will service the installed cable tray system. The flexibility and scalability of cable trays make them an ideal choice for environments where cable density and organization can. A cable tray grounding is best inspected by searching cable tray sections with bonding jumpers (the thick green or copper wires connecting various sections of the tray) and checking them with a device known as a multimeter. When the connection is very close, and the meter indicates a low resistance. Total cross-sectional area of both side rails for ladder or trough-type cable trays: or the minimum cross-sectional area of metal in channel-type cable trays or cable trays of one-piece construction.
