The third of five bonding-related terms defined in Art. 100 of the NEC is "bonding jumper, equipment." The definition may be confusing, leading to bad practices. The Art. 100 definition is: “The connection between two or more portions of the equipment grounding conductor.”
The confusion arises in the word “grounding.” An equipment grounding conductor (EGC), if installed properly, isn’t actually grounding the equipment it’s connected to.
Article 100 defines “ground” as a connection to the earth. If you just drive a bunch of ground rods at each piece of equipment, you’ll have dangerous difference of potential. You won’t have accomplished anything that meets any electrical purpose.
The EGC is actually an equipment bonding conductor. One of the things it does is bring metallic objects to the same level of electrical potential. Doing this not only eliminates a source of potentially lethal shock, it also prevents undesirable current from flowing through the equipment (because current flows only when there is a difference of potential).
The EGC system does terminate to the grounding system, so in that sense the whole system grounds equipment. But the primary benefits are from the bonding. The ground connection must be made to this system, rather than to individual points of use or equipment.
