IEC - Independent Electrical Contractors Special Occupancies and Equipment Questions and Answers — Questions and Answers
Question 1: An electrician is installing wiring for a branch circuit in a patient care space of a hospital. According to NEC Article 517, which of the following wiring methods is required to ensure a redundant grounding path?
- Type NM cable with an insulated equipment grounding conductor.
- PVC conduit with an insulated copper equipment grounding conductor.
- Metal-clad (Type MC) cable with a metallic sheath that qualifies as an equipment grounding conductor and an insulated copper equipment grounding conductor. (Correct answer)
- Flexible metal conduit (FMC) with an external bonding jumper.
Correct answer: Metal-clad (Type MC) cable with a metallic sheath that qualifies as an equipment grounding conductor and an insulated copper equipment grounding conductor.
NEC 517.13 requires branch circuits serving patient care spaces to be installed in a metal raceway or a cable with a metallic sheath that provides an effective ground-fault current path. Additionally, an insulated copper equipment grounding conductor must be installed with the branch circuit conductors. This creates two separate equipment grounding paths for enhanced safety.
Question 2: When installing a 125-volt, single-phase, 20-ampere receptacle near a permanently installed swimming pool, what is the minimum required horizontal distance from the inside walls of the pool?
- No minimum distance is required if it is GFCI protected.
- 3 feet
- 10 feet
- 6 feet (Correct answer)
Correct answer: 6 feet
According to NEC 680.22(A)(3), receptacles that are not for pool equipment must be located at least 6 feet horizontally from the inside walls of the pool. Additionally, 680.22(A)(4) requires any 125-volt, 15- or 20-ampere receptacle located within 20 feet of the inside walls of the pool to be GFCI protected.
Question 3: In a commercial repair garage, the area up to 18 inches above the floor is classified as a Class I, Division 2 location. Which wiring method is permitted for fixed wiring installed ABOVE this classified location?
- Exposed Type NM (Romex) cable
- Electrical Metallic Tubing (EMT) (Correct answer)
- PVC conduit without any special fittings
- Type UF cable
Correct answer: Electrical Metallic Tubing (EMT)
NEC 511.7(A)(1) permits several wiring methods for fixed wiring above Class I locations in commercial garages, including metal raceways like RMC, IMC, or EMT. Non-metallic sheathed cables like NM and UF are not permitted for this application.
Question 4: An equipotential plane is required in an agricultural building that houses livestock in a confinement area with a concrete floor. What is the minimum size solid copper bonding conductor required to connect this plane to the electrical grounding system?
- 10 AWG
- 6 AWG
- 8 AWG (Correct answer)
- 4 AWG
Correct answer: 8 AWG
NEC 547.10(B) (renumbered to 547.44(B) in some editions) mandates that the bonding conductor for an equipotential plane in an agricultural building shall be solid copper, insulated, covered, or bare, and not smaller than 8 AWG.
Question 5: At a marina, what is the maximum ground-fault protection (GFP) setting permitted for the main overcurrent device supplying a dock where shore power is provided to boats?
- 5 mA
- 30 mA
- 100 mA (Correct answer)
- 1000 mA
Correct answer: 100 mA
NEC 555.35(A)(3) requires that feeder and branch-circuit conductors installed on docking facilities be provided with ground-fault protection of equipment (GFPE) set to open at currents not exceeding 100 mA. Receptacles providing shore power have a lower 30 mA requirement.
Question 6: For a carnival ride, NEC Article 525 requires a disconnecting means to be located within sight of and within what maximum distance from the operator's station?
- 10 feet
- 6 feet (Correct answer)
- 25 feet
- 50 feet
Correct answer: 6 feet
NEC 525.21(A) specifies that each portable structure, such as a ride or concession, must have a disconnecting means located within sight of and within 6 feet of the operator's station. This allows for rapid shutdown in an emergency.
IEC - Independent Electrical Contractors Special Occupancies and Equipment Questions and Answers
An electrician is installing wiring for a branch circuit in a patient care space of a hospital.
According to NEC Article 517, which of the following wiring methods is required to ensure a redundant grounding path?