Free TN LLE Special Occupancies and Equipment Questions and Answers — Questions and Answers
Question 1: An electrician is installing a 120V incandescent luminaire (lighting fixture) located 8 feet horizontally from the inside wall of a permanently installed swimming pool. According to NEC Article 680, which of the following is required for this installation?
- The luminaire must be rigidly attached to the structure.
- The circuit supplying the luminaire must be protected by a Ground-Fault Circuit-Interrupter (GFCI). (Correct answer)
- The luminaire must be installed at least 12 feet above the maximum water level.
- The luminaire must be controlled by a switch located at least 10 feet from the pool's edge.
Correct answer: The circuit supplying the luminaire must be protected by a Ground-Fault Circuit-Interrupter (GFCI).
According to NEC 680.22(B)(4), luminaires installed in the area extending between 5 ft and 10 ft horizontally from the inside walls of a pool must be protected by a GFCI unless they are installed at least 5 ft above the maximum water level and rigidly attached to the structure. Since the height is not specified, GFCI protection is the mandatory requirement.
Question 2: In a commercial garage used for major vehicle repair, which area is generally classified as a Class I, Division 2 hazardous location?
- The entire area within 5 feet of any fuel dispensing equipment.
- Any pit or depression below floor level, extending up to the floor level.
- The area from the floor up to a level of 18 inches above the floor. (Correct answer)
- The area within 36 inches of the ceiling where lighter-than-air fuel is used.
Correct answer: The area from the floor up to a level of 18 inches above the floor.
NEC Article 511.3(B)(1) states that for a floor at or above grade in a major repair garage, the entire area up to a level of 18 inches above the floor is considered a Class I, Division 2 location. This is due to the potential presence of flammable fuel vapors, which are typically heavier than air and accumulate near the floor.
Question 3: Which of the following wiring methods is required for branch circuits serving patient care spaces in a health care facility?
- Non-metallic sheathed cable (Type NM-B).
- Underground Feeder (Type UF) cable.
- A metal raceway or a cable with a metallic sheath. (Correct answer)
- Any wiring method suitable for damp locations.
Correct answer: A metal raceway or a cable with a metallic sheath.
NEC 517.13(A) requires that all branch circuits serving patient care spaces be installed in a metal raceway or a cable with a metallic armor or sheath (e.g., Type AC or MC cable). This provides an effective ground-fault current path and enhanced physical protection, which is critical for patient safety.
Question 4: An electrician is wiring a livestock confinement area in an agricultural building, which is subject to a corrosive atmosphere from animal waste. According to NEC Article 547, which of the following wiring methods is generally permitted?
- Type NMC (nonmetallic-sheathed cable). (Correct answer)
- Standard Type NM-B (nonmetallic-sheathed cable).
- Electrical Metallic Tubing (EMT).
- Flexible Metal Conduit (FMC).
Correct answer: Type NMC (nonmetallic-sheathed cable).
NEC 547.5 specifies permitted wiring methods for agricultural buildings, especially in areas with dust, moisture, and corrosive atmospheres. Type NMC cable, which has a corrosion-resistant outer jacket, is listed as a suitable method. Standard Type NM-B, EMT, and FMC are generally not suitable for such corrosive environments without additional protection.
Question 5: When installing a 125V, 20-amp shore power receptacle on a fixed pier at a marina, what is the minimum mounting height above the deck surface according to NEC Article 555?
- 6 inches
- 12 inches (Correct answer)
- 18 inches
- The height is not specified, but it must be in a weatherproof enclosure.
Correct answer: 12 inches
While specific local amendments can vary, the NEC and related standards generally establish a minimum height to protect receptacles from water. For example, some jurisdictions explicitly adopt NEC 555.33 and specify that receptacles must be mounted not less than 12 inches above the deck surface of the pier. This helps prevent submersion from splashing or high water levels.
Question 6: An electrician is installing a dedicated 240V branch circuit for a Level 2 Electric Vehicle Supply Equipment (EVSE) that has a maximum continuous load rating of 40 amps. What is the minimum required rating for the branch-circuit overcurrent protective device?
- 40 amps
- 60 amps
- 50 amps (Correct answer)
- 45 amps
Correct answer: 50 amps
According to NEC 625.41, the overcurrent protection for a branch circuit supplying an EVSE must be rated for not less than 125% of the maximum load. Since EV charging is considered a continuous load, the calculation is 40 amps × 1.25 = 50 amps. Therefore, a 50-amp circuit breaker is required.
Free TN LLE Special Occupancies and Equipment Questions and Answers
An electrician is installing a 120V incandescent luminaire (lighting fixture) located 8 feet horizontally from the inside wall of a permanently installed swimming pool.
According to NEC Article 680, which of the following is required for this installation?