Grounding and Bonding Flashcards

According to NEC Article 250, what is the minimum size copper equipment grounding conductor required for a 100A circuit protected by a 100A breaker?

Answer: #8 AWG

NEC Table 250.122 requires a minimum #8 AWG copper EGC for circuits with overcurrent protection rated at 100A.

Which of the following locations requires a grounding electrode system to include a ground ring if no other electrode is available?

Answer: Buildings or structures where no other electrode type exists on-site

NEC 250.52(A)(4) allows a ground ring as a grounding electrode when other electrode types are unavailable at the structure.

What is the primary purpose of bonding in an electrical system?

Answer: To establish electrical continuity between conductive parts to eliminate voltage differences

Bonding ensures electrical continuity between conductive parts so no dangerous voltage differences exist between them.

A concrete-encased electrode (Ufer ground) must contain at least how many feet of bare or zinc-galvanized steel reinforcing bars or rods?

Answer: 20 feet

NEC 250.52(A)(3) requires at least 20 feet of steel reinforcing bar or rod encased in concrete for a Ufer ground.

When installing a grounding electrode conductor in a metal raceway, what additional requirement applies?

Answer: The raceway must be bonded to the grounding electrode conductor at both ends

NEC 250.64(E) requires that when a GEC is installed in metal raceway, the raceway must be bonded to the GEC at both ends to prevent inductive choke.

Which NEC article specifically addresses grounding and bonding requirements?

Answer: Article 250

NEC Article 250 covers all grounding and bonding requirements for electrical installations.

In a separately derived system (e.g., a transformer), where must the system bonding jumper be installed?

Answer: At the source of the separately derived system

NEC 250.30(A)(1) requires the system bonding jumper to be installed at the source of the separately derived system.