Grounding and Bonding Flashcards
7 cards from real IEC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Grounding and Bonding flashcards as text
In a feeder circuit, if the equipment grounding conductor is increased in size above the minimum required by Table 250.122, what must also be increased proportionally?
Answer: The neutral conductor
Per NEC 250.122(B), if the ungrounded conductors are increased in size, the equipment grounding conductor must be increased proportionally — and the neutral must also be evaluated for proper sizing.
Per NEC 250.64(B), a grounding electrode conductor installed exposed on the exterior of a building must be protected from physical damage by:
Answer: Iron or steel conduit, PVC conduit, EMT, or other approved means
NEC 250.64(B) permits the grounding electrode conductor to be protected by iron/steel conduit, PVC conduit, EMT, or other approved means when exposed to physical damage.
When multiple electrodes are installed to meet code requirements, what is the minimum spacing between driven ground rods per NEC 250.53(B)?
Answer: 6 feet
NEC 250.53(B) requires that where multiple rod, pipe, or plate electrodes are installed, they must be spaced at least 6 feet apart.
Which of the following conditions allows a single ground rod to serve as the only grounding electrode without a supplemental electrode?
Answer: When the resistance to ground is 25 ohms or less
Per NEC 250.56, a single rod electrode does not require supplemental electrodes if the measured resistance to ground is 25 ohms or less.
What NEC section governs bonding requirements for swimming pools, hot tubs, and similar installations?
Answer: Article 680
Article 680 covers the special requirements for swimming pools, fountains, and similar installations, including the equipotential bonding requirements.
The term 'effective ground-fault current path' as defined in the NEC is an intentionally constructed, permanent, low-impedance path that facilitates what?
Answer: The operation of the overcurrent protective device during a ground fault
An effective ground-fault current path is designed to carry enough fault current to quickly operate the overcurrent protective device and clear the fault.
Per NEC 250.30(A), a separately derived system must establish a grounding electrode conductor connection at which location?
Answer: At the source of the separately derived system (the transformer itself)
NEC 250.30(A) requires the grounding electrode conductor for a separately derived system to connect at the source — the transformer — not at downstream equipment.