CEA Wiring Methods & Installation Practices 2 — Questions and Answers
Question 1: What is the minimum burial depth for rigid metal conduit (RMC) under a residential driveway?
- 6 inches
- 12 inches (Correct answer)
- 18 inches
- 24 inches
Correct answer: 12 inches
RMC requires a minimum burial depth of 6 inches under a residential driveway, but 12 inches is the NEC standard for RMC under driveways subject to vehicular traffic.
Question 2: Which wiring method is NOT permitted in a Class I, Division 1 hazardous location?
- Rigid metal conduit (RMC)
- Type MI cable
- Flexible metal conduit (FMC) (Correct answer)
- Threaded rigid steel conduit
Correct answer: Flexible metal conduit (FMC)
Standard flexible metal conduit is not permitted in Class I, Division 1 hazardous locations because it cannot maintain an explosion-proof seal.
Question 3: When installing EMT in a concrete slab, which requirement applies?
- EMT is prohibited in concrete
- EMT must be coated or corrosion-resistant when encased in concrete (Correct answer)
- EMT requires no special treatment in concrete
- EMT must be wrapped with tape only
Correct answer: EMT must be coated or corrosion-resistant when encased in concrete
EMT encased in concrete must be made of steel listed for the purpose or protected by a listed corrosion-resistant coating.
Question 4: What is the maximum number of 90-degree bends allowed between pull points in a conduit run?
- Two 90-degree bends
- Three 90-degree bends
- Four 90-degree bends (Correct answer)
- Five 90-degree bends
Correct answer: Four 90-degree bends
The NEC limits conduit runs to a total of 360 degrees (four 90-degree bends) of bends between pull points to allow wire to be pulled without damage.
Question 5: Type AC cable (armored cable) must be secured within how many inches of every box or fitting?
- 6 inches
- 8 inches
- 12 inches (Correct answer)
- 18 inches
Correct answer: 12 inches
Type AC cable must be secured within 12 inches of every box, cabinet, or fitting and at intervals not exceeding 4.5 feet.
Question 6: A cable installed through a floor must be protected from physical damage up to what height above the floor?
- 4 feet
- 6 feet
- 7 feet (Correct answer)
- 8 feet
Correct answer: 7 feet
Cables passing through a floor must be protected by rigid metal conduit, IMC, Schedule 80 PVC, or equivalent protection to a height of 6 feet above the floor.
Question 7: When installing PVC conduit exposed to sunlight, what additional requirement applies?
- PVC must be painted white
- PVC must be listed and marked as sunlight-resistant (Correct answer)
- PVC must be enclosed in metallic conduit
- PVC requires no special treatment for sunlight
Correct answer: PVC must be listed and marked as sunlight-resistant
PVC conduit exposed to sunlight must be listed and marked as sunlight-resistant to prevent UV degradation.
CEA Wiring Methods & Installation Practices 2
What is the minimum burial depth for rigid metal conduit (RMC) under a residential driveway?