Practice Test GeeksIEC - Independent Electrical Contractors Practice Test
← All IEC Flashcard Decks

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

  1. What is the maximum resistance to ground allowed for a single ground rod electrode before a supplemental electrode is required per NEC 250.56?

    Answer: 25 ohms

    NEC 250.56 requires a supplemental electrode if a single rod, pipe, or plate electrode has a resistance to ground exceeding 25 ohms.

  2. Which conductor is used to bond the structural steel of a building to the grounding electrode system?

    Answer: Grounding electrode conductor

    The grounding electrode conductor connects the grounding electrode system to the electrical system, including structural steel when used as an electrode.

  3. Per NEC 250.104(A), interior metal water piping must be bonded to which of the following?

    Answer: The service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor, or the grounding electrodes

    NEC 250.104(A) requires interior metal water piping to be bonded to the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor, or one of the grounding electrodes.

  4. What type of grounding electrode is considered 'made' rather than 'existing' per NEC 250.52?

    Answer: Rod and pipe electrode

    Rod and pipe electrodes are intentionally installed (made) electrodes, whereas water pipes, building steel, and concrete-encased electrodes are naturally occurring or part of the structure.

  5. What is the minimum length of a ground rod required by NEC 250.52(A)(5)?

    Answer: 8 feet

    NEC 250.52(A)(5) requires ground rods to be at least 8 feet in length when installed in the earth.

  6. In a separately derived system (such as a transformer), the bonding jumper connecting the grounded conductor to the equipment grounding conductor is called a:

    Answer: System bonding jumper

    The system bonding jumper performs the same function as a main bonding jumper but is used at a separately derived system rather than at the service.

  7. Bonding of gas piping systems in a building is required by NEC 250.104(B) to ensure:

    Answer: Electrical continuity so that fault current can flow and trip overcurrent devices

    Gas piping must be bonded to ensure electrical continuity so that any fault current can flow through the system and operate the overcurrent protective device.