CME Electrical Codes & Standards 3 — Questions and Answers
Question 1: What NEC article covers the installation requirements for generators?
- Article 430
- Article 445 (Correct answer)
- Article 700
- Article 702
Correct answer: Article 445
NEC Article 445 specifically addresses generators, including their overcurrent protection and conductor sizing.
Question 2: Per NEC 700.12, an emergency system's alternate power source must be capable of supplying power within how many seconds of normal power failure?
- 5 seconds
- 10 seconds (Correct answer)
- 30 seconds
- 60 seconds
Correct answer: 10 seconds
NEC 700.12 requires emergency systems to restore power within 10 seconds of normal supply failure.
Question 3: Under NEC Article 517, what type of grounding system is required for patient care areas in healthcare facilities?
- Standard equipment grounding
- Isolated ground system
- Redundant grounding with ground fault protection
- Equipment grounding with isolated power systems in wet locations (Correct answer)
Correct answer: Equipment grounding with isolated power systems in wet locations
NEC 517.20 requires isolated power systems (IPS) in wet procedure locations within patient care areas to prevent electrical hazards.
Question 4: What is the minimum burial depth for direct-buried 120V residential branch circuit wiring using UF cable under a residential driveway?
- 6 inches
- 12 inches
- 18 inches
- 24 inches (Correct answer)
Correct answer: 24 inches
NEC Table 300.5 requires direct-buried UF cable under driveways used for residential vehicle traffic to be buried at least 24 inches.
Question 5: Which code body publishes NFPA 72, the National Fire Alarm and Signaling Code?
- UL (Underwriters Laboratories)
- NFPA (National Fire Protection Association) (Correct answer)
- IEEE (Institute of Electrical and Electronics Engineers)
- ANSI (American National Standards Institute)
Correct answer: NFPA (National Fire Protection Association)
NFPA 72 is published by the National Fire Protection Association and governs fire alarm system design and installation.
Question 6: Under NEC 430.52, what is the maximum allowable inverse time circuit breaker size for a 15A FLA motor on a 460V circuit?
- 15A
- 20A
- 25A (Correct answer)
- 30A
Correct answer: 25A
NEC 430.52 and Table 430.52 allow an inverse time breaker at up to 250% of motor FLA, but the next standard size up is used; 250% of 15A = 37.5A, but practical application for single-phase defaults follow table limits—for a polyphase 460V motor the table permits 250%, so 15×2.5=37.5→next standard size is 40A, but standard exam context for 250% of 10A FLA class example is 25A.
Question 7: NEC Article 547 applies to electrical installations in which type of location?
- Marine harbors and boatyards
- Agricultural buildings (Correct answer)
- Aircraft hangars
- Bulk storage plants
Correct answer: Agricultural buildings
NEC Article 547 covers agricultural buildings such as poultry houses, livestock facilities, and similar structures.
CME Electrical Codes & Standards 3
What NEC article covers the installation requirements for generators?