Grounding and Bonding Flashcards
7 cards from real PC 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
Structural steel of a building may be used as a grounding electrode if it is connected to at least how many ground rods, concrete-encased electrodes, or ground rings?
Answer: Two
NEC 250.52(A)(2) permits building steel as a grounding electrode when it is connected to at least two ground rods, concrete-encased electrodes, or ground rings.
When installing a ground rod in rocky soil where the required 8-foot depth cannot be achieved vertically, what is the alternative permitted by NEC 250.53(G)?
Answer: Drive the rod at a 45-degree angle or bury it horizontally at 30 inches depth
NEC 250.53(G) allows rods that cannot be driven vertically to be installed at up to a 45-degree angle or buried horizontally at a minimum 30-inch depth.
What NEC section governs the bonding of metal gas piping systems in a building?
Answer: NEC 250.104(B)
NEC 250.104(B) requires metal gas piping to be bonded to the electrical service equipment, the grounded conductor, or the grounding electrode conductor.
In a health care facility, which grounding system is required in patient care areas to minimize leakage current?
Answer: Patient equipment grounding point (PEGP) with redundant EGC paths
NFPA 99 and NEC 517 require patient equipment grounding points providing redundant low-impedance EGC paths to protect patients from microshock hazards.
Which statement correctly describes the difference between grounding and bonding?
Answer: Grounding connects equipment to earth; bonding connects conductive parts to each other to equalize potential
Grounding establishes a reference to earth potential, while bonding ensures electrical continuity between conductive parts to eliminate potential differences between them.
For a 400A service, NEC Table 250.122 requires a minimum equipment grounding conductor size of what if using copper?
Answer: #3 AWG
NEC Table 250.122 requires a minimum #3 AWG copper EGC for circuits with overcurrent protection rated at 400A.
An isolated ground (IG) receptacle is used primarily to:
Answer: Provide a separate, insulated EGC run back to the panel to reduce electrical noise for sensitive equipment
IG receptacles provide a dedicated, insulated EGC that runs back to the panel separately to minimize electrical noise interference for sensitive electronic equipment.