E2 General Requirements and NEC 2 — Questions and Answers
Question 1: Under the NEC, what is the minimum headroom required in front of electrical equipment rated 600V or less that requires examination, adjustment, servicing, or maintenance while energized?
- 4 feet
- 5 feet
- 6 feet (Correct answer)
- 6.5 feet
Correct answer: 6 feet
NEC 110.26(A)(1) requires a minimum of 6 feet of headroom for working space in front of electrical equipment rated 600V or less.
Question 2: Which NEC article governs the installation of conductors and equipment in locations where fire or explosion hazards may exist due to flammable gases?
- Article 500
- Article 501 (Correct answer)
- Article 502
- Article 503
Correct answer: Article 501
NEC Article 501 specifically covers Class I locations where flammable gases or vapors may be present in the air in quantities sufficient to produce explosive or ignitable mixtures.
Question 3: When conductors of different systems are installed in the same raceway, what is a key NEC requirement?
- They must be color-coded differently
- All conductors must have the same voltage rating as the highest voltage present (Correct answer)
- They must be separated by an insulating barrier
- The raceway must be metallic
Correct answer: All conductors must have the same voltage rating as the highest voltage present
Per NEC 300.3(C)(1), all conductors in a raceway must have an insulation rating equal to at least the maximum circuit voltage present.
Question 4: The NEC defines a 'qualified person' in Article 100 as someone who has:
- A minimum of 5 years of electrical experience
- Skills and knowledge related to the construction and operation of electrical equipment and has received safety training to recognize and avoid the hazards involved (Correct answer)
- A valid electrical contractor's license
- Completed an apprenticeship program
Correct answer: Skills and knowledge related to the construction and operation of electrical equipment and has received safety training to recognize and avoid the hazards involved
NEC Article 100 defines a qualified person based on skills, knowledge, and safety training—not solely on years of experience or licensing.
Question 5: Per NEC 210.8, GFCI protection is required for all 125V, single-phase, 15A and 20A receptacles in commercial bathrooms because:
- They are in a damp location
- They are in a wet location
- The NEC requires it for all commercial occupancies regardless of location (Correct answer)
- They are within 6 feet of a sink
Correct answer: The NEC requires it for all commercial occupancies regardless of location
NEC 210.8(B) requires GFCI protection for receptacles in commercial bathrooms without regard to proximity to water sources.
Question 6: What does NEC Article 110.14 address regarding electrical connections?
- Voltage drop limitations
- Conductor termination and splicing requirements (Correct answer)
- Minimum wire gauge for branch circuits
- Overcurrent protection sizing
Correct answer: Conductor termination and splicing requirements
NEC 110.14 covers the requirements for electrical connections, including the use of listed devices, proper termination methods, and temperature ratings for conductors and terminals.
Question 7: Under the NEC, which of the following is NOT a recognized wiring method for use in commercial buildings?
- Electrical metallic tubing (EMT)
- Rigid polyvinyl chloride conduit (PVC)
- Open wiring on insulators in concealed spaces (Correct answer)
- Metal-clad cable (MC)
Correct answer: Open wiring on insulators in concealed spaces
Open wiring on insulators (Article 398) is generally restricted to industrial or agricultural settings and is not a recognized method for concealed spaces in commercial buildings.
