E2 General Requirements and NEC 3 — Questions and Answers
Question 1: When the NEC refers to 'authority having jurisdiction' (AHJ), it means:
- The National Fire Protection Association
- The organization, office, or individual responsible for enforcing the requirements of the Code (Correct answer)
- The electrical contractor of record
- The state electrical licensing board
Correct answer: The organization, office, or individual responsible for enforcing the requirements of the Code
The AHJ is defined in NEC Article 100 as the organization, office, or individual responsible for enforcing the Code or their designated representative.
Question 2: NEC 230.70 requires the service disconnecting means to be installed:
- Inside the building near the main panel
- Outside the building or inside nearest the point of entrance of service conductors (Correct answer)
- At the utility metering point
- In a locked electrical room
Correct answer: Outside the building or inside nearest the point of entrance of service conductors
NEC 230.70(A)(1) requires the service disconnecting means to be located outside a building or structure, or inside nearest the point of entrance of the service conductors.
Question 3: Per NEC 300.5, direct burial cable must be installed at what minimum depth under a commercial parking lot or driveway?
- 12 inches
- 18 inches
- 24 inches (Correct answer)
- 30 inches
Correct answer: 24 inches
NEC Table 300.5 requires a minimum burial depth of 24 inches under commercial driveways and parking areas for direct burial conductors.
Question 4: Which NEC section establishes the requirement that all electrical equipment be listed and labeled by a nationally recognized testing laboratory (NRTL)?
- NEC 90.7
- NEC 110.2
- NEC 110.3 (Correct answer)
- NEC 110.4
Correct answer: NEC 110.3
NEC 110.3 requires that all equipment be approved (listed and labeled) and installed in accordance with any instructions included in the listing or labeling.
Question 5: According to NEC 408.4, what information must be legibly identified on each circuit in a panelboard?
- Wire gauge and circuit length
- The purpose or equipment served and voltage (Correct answer)
- The overcurrent device amperage only
- The date of installation and installer's name
Correct answer: The purpose or equipment served and voltage
NEC 408.4(A) requires each circuit to be legibly identified as to its clear, evident, and specific purpose or the equipment served, including voltage if other than nominal.
Question 6: The NEC general requirement for working clearances (NEC 110.26) applies to equipment operating at:
- Any voltage
- 50V or more (Correct answer)
- 120V or more
- 600V or less (the section only covers up to 600V)
Correct answer: 50V or more
NEC 110.26 applies to equipment likely to require examination, adjustment, servicing, or maintenance while energized and operating at 50V or more.
Question 7: Per NEC 250.52, which of the following is NOT an acceptable grounding electrode?
- Metal underground water pipe in contact with the earth for at least 10 feet
- Concrete-encased electrode (Ufer ground)
- Underground metal gas piping (Correct answer)
- Ground ring encircling the building
Correct answer: Underground metal gas piping
NEC 250.52(B)(1) specifically prohibits underground metal gas piping from being used as a grounding electrode due to corrosion and safety concerns.
E2 General Requirements and NEC 3
When the NEC refers to 'authority having jurisdiction' (AHJ), it means: