Which of the following is not a true statement concerning an equipment grounding conductor?

• A. Under certain conditions, equipment grounding conductors may be run in parallel.
• B. The size of equipment grounding conductors shall be increased where ungrounded conductors are increased in size.
• C. Under certain conditions, equipment grounding conductors shall be required to be larger than circuit conductors supplying the equipment.
• D. One equipment grounding conductor may serve multiple circuits.

Answer: (C)

The main idea here is how equipment grounding conductors (EGCs) are sized and used to provide a safe fault path. The EGC’s job is to carry fault current back to the source so the protective device trips quickly, and its minimum size is determined by the rating of the overcurrent device protecting the circuit (see Table 250.122). When ungrounded conductors are increased in size, the EGC size is increased accordingly to maintain an adequate fault-path capability. EGCs can be run in parallel under certain conditions to achieve the necessary cross-section for large fault currents, and one EGC can serve multiple circuits when they share a common grounding system. The statement that is not correct is that the EGC must be larger than the circuit conductors supplying the equipment under some conditions—the EGC is sized based on the overcurrent protection rating and is not required to be inherently larger than the current-carrying conductors.