EETC Wiring Methods 2 — Questions and Answers
Question 1: What is the maximum number of 90-degree bends permitted in a single run of rigid metal conduit (RMC) between pull points?
- Two 90-degree bends
- Three 90-degree bends
- Four 90-degree bends (Correct answer)
- Five 90-degree bends
Correct answer: Four 90-degree bends
NEC 358.26 limits the total bends to 360 degrees (equivalent to four 90-degree bends) between pull points in EMT and RMC runs.
Question 2: Which wiring method is specifically listed for use in hazardous (classified) locations Class I, Division 1?
- Type NM cable
- Electrical metallic tubing (EMT)
- Rigid metal conduit (RMC) (Correct answer)
- Type AC cable
Correct answer: Rigid metal conduit (RMC)
Rigid metal conduit (RMC) is one of the approved wiring methods for Class I, Division 1 hazardous locations per NEC Article 501.
Question 3: When installing PVC conduit underground, what is the minimum cover required for a branch circuit rated 120V or less under a residential driveway?
- 6 inches
- 12 inches
- 18 inches (Correct answer)
- 24 inches
Correct answer: 18 inches
NEC Table 300.5 requires 18 inches of cover for PVC conduit under residential driveways for circuits 120V or less.
Question 4: What is the minimum radius for a field bend in 2-inch RMC?
- 6 inches
- 8 inches
- 9.5 inches (Correct answer)
- 15 inches
Correct answer: 9.5 inches
NEC Table 344.24 specifies a minimum bend radius of 9.5 inches for 2-inch RMC to prevent conductor damage.
Question 5: Type UF cable differs from Type NM cable primarily because UF cable is:
- Rated for higher ampacity
- Suitable for direct burial in the earth (Correct answer)
- Approved for use in attics
- Permitted in commercial buildings
Correct answer: Suitable for direct burial in the earth
Type UF (Underground Feeder) cable has a moisture-resistant, sunlight-resistant jacket approved for direct burial per NEC 340.10.
Question 6: Which of the following conduit types is NOT permitted to be used as an equipment grounding conductor?
- Rigid metal conduit (RMC)
- Electrical metallic tubing (EMT)
- Rigid polyvinyl chloride conduit (PVC) (Correct answer)
- Intermediate metal conduit (IMC)
Correct answer: Rigid polyvinyl chloride conduit (PVC)
PVC conduit is a non-metallic raceway and cannot serve as an equipment grounding conductor; a separate EGC must be installed.
Question 7: When using flexible metal conduit (FMC) for a motor connection, what is the maximum length permitted without an additional equipment grounding conductor?
- 3 feet
- 6 feet (Correct answer)
- 10 feet
- 20 feet
Correct answer: 6 feet
NEC 350.60 allows FMC up to 6 feet to serve as the EGC provided it meets the listed conditions, including a minimum trade size of ½ inch.
EETC Wiring Methods 2
What is the maximum number of 90-degree bends permitted in a single run of rigid metal conduit (RMC) between pull points?