ESC Electrical Grounding & Bonding Flashcards
6 cards from real ESC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 ESC Electrical Grounding & Bonding flashcards as text
What color is used to identify an isolated grounding conductor?
Answer: Green with a yellow stripe
An isolated grounding conductor is identified by green insulation with a yellow stripe, distinguishing it from a standard equipment grounding conductor.
In a 3-phase, 4-wire wye system, which conductor is the system grounded conductor?
Answer: The neutral conductor
In a 3-phase wye system, the neutral conductor derived from the center point of the wye is the system grounded conductor.
What is the primary purpose of equipotential bonding in wet locations such as swimming pools?
Answer: To ensure all conductive surfaces are at the same voltage, preventing shock
Equipotential bonding ensures all conductive surfaces in and around a pool are at the same potential, eliminating the voltage gradients that cause electrical shock.
What is the minimum diameter required for a copper or copper-clad steel ground rod per NEC 250.52?
Answer: 5/8 inch
NEC 250.52(A)(5) requires copper or copper-clad steel ground rods to have a minimum diameter of 5/8 inch.
When multiple ground rods are installed, what is the minimum spacing required between them per NEC 250.53?
Answer: 6 feet
NEC 250.53(B) requires multiple ground rods to be spaced at least 6 feet apart so their resistance areas do not significantly overlap.
When is a neutral-to-ground bond permitted at a sub-panel located in a separate building?
Answer: When the sub-panel is the first disconnect for that separate building and there is no continuous metallic path back to the main panel
A neutral-to-ground bond in a sub-panel in a separate building is permitted only when the sub-panel serves as the first means of disconnect and no continuous metallic path exists back to the main panel.