Are the cable tray jumpers outside the connecting plate
Whether you need extra wires (jumpers) depends on if your connecting plates are tested for grounding. If the plates are UL Classified, they are strong enough to carry electricity safely by themselves. They are required to be used on locations where the tray is not continuously grounded or when splice plates that aren't UL listed are used. Cable trays are holding SOOW cords from a control trailer with starters to crusher motors but are not continuous and are in sections away from each other. Cable tray may be used as the Equipment Grounding Conductor (EGC) in any installation where qualified persons will service the installed cable tray system.
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