Free NEC Special Occupancies Questions and Answers — Questions and Answers
Question 1: An electrician is installing wiring for a branch circuit serving a patient bed location in a hospital's general care area. According to NEC Article 517, which of the following is a requirement for the wiring method?
- The wiring must be installed in a metallic raceway or a cable with a metallic sheath. (Correct answer)
- Type NM cable is permitted if concealed within walls.
- An insulated equipment grounding conductor is optional if the raceway is metallic.
- PVC conduit is a permitted wiring method.
Correct answer: The wiring must be installed in a metallic raceway or a cable with a metallic sheath.
NEC Section 517.13(A) requires that branch circuits serving patient care spaces be installed in a metal raceway or a cable with a metallic armor or sheath that qualifies as an equipment grounding conductor under 250.118. This is to provide a reliable ground-fault current path.
Question 2: Which of the following wiring methods is generally permitted in an assembly occupancy with a fire-rated construction, such as a theater intended to hold over 100 people?
- Electrical Nonmetallic Tubing (ENT) concealed in the ceiling.
- Type AC (Armored Cable). (Correct answer)
- Nonmetallic-sheathed cable (Type NM).
- Rigid Nonmetallic Conduit (RNC) embedded in the floor.
Correct answer: Type AC (Armored Cable).
According to NEC 518.4(A), in an assembly occupancy required to have fire-rated construction, wiring methods must be metal raceways, flexible metal raceways, or specific cable types like Type MI, AC, or MC. Type AC cable is explicitly permitted. Nonmetallic methods are generally restricted to areas not required to be fire-rated.
Question 3: An equipotential plane is being installed in a concrete floor of a livestock confinement area within an agricultural building. What is the MINIMUM size solid copper bonding conductor required to connect this plane to the electrical grounding system?
- 10 AWG
- 6 AWG
- 12 AWG
- 8 AWG (Correct answer)
Correct answer: 8 AWG
NEC 547.44(B) specifies that the bonding conductor for an equipotential plane in an agricultural building shall be a solid copper conductor, insulated, covered, or bare, and not smaller than 8 AWG.
Question 4: An electrician is installing service equipment for a new floating dock at a marina. According to NEC Article 555, where must this service equipment be located?
- On the floating dock itself for easy access.
- On an adjacent floating structure connected to the dock.
- On land, adjacent to the structure served. (Correct answer)
- At the shore end of the gangway, mounted directly to it.
Correct answer: On land, adjacent to the structure served.
NEC 555.4 mandates that the service equipment for a floating dock or marina must be located on land adjacent to the structure served, but not on or in the floating structure itself. It also specifies minimum horizontal and vertical distances from the water.
Question 5: For temporary electrical power and lighting installations on a construction site, what is the general time limit for such an installation before it must be removed or replaced with a permanent system?
- 30 days
- 6 months
- The duration of the construction project
- 90 days (Correct answer)
Correct answer: 90 days
According to NEC 590.3(A), temporary electrical power and lighting installations shall be permitted for a period not to exceed 90 days for purposes such as construction, remodeling, or similar activities.
Question 6: Which of the following is a requirement for an underwater luminaire installed in a permanently installed swimming pool?
- The branch-circuit conductors must include an insulated copper equipment grounding conductor no smaller than 12 AWG. (Correct answer)
- The luminaire can be supplied by a standard autotransformer.
- The forming shell is not required to be bonded to the equipotential grid.
- Splicing of the equipment grounding conductor is permitted in the conduit.
Correct answer: The branch-circuit conductors must include an insulated copper equipment grounding conductor no smaller than 12 AWG.
NEC 680.23(F)(2) requires that the branch-circuit conductors for an underwater luminaire contain an insulated copper equipment grounding conductor sized per Table 250.122, but not smaller than 12 AWG. This ensures a reliable grounding connection in this critical, wet location.
Free NEC Special Occupancies Questions and Answers
An electrician is installing wiring for a branch circuit serving a patient bed location in a hospital's general care area.
According to NEC Article 517, which of the following is a requirement for the wiring method?