CEA Conduit Bending and Installation 4 — Questions and Answers
Question 1: When bending a back-to-back (U-bend) in conduit, the second bend must be placed so that:
- The gain is added to the distance between bends
- The two 90-degree bends face each other and the legs are parallel (Correct answer)
- The conduit crosses at a 45-degree angle
- The inside diameter is reduced by no more than 5%
Correct answer: The two 90-degree bends face each other and the legs are parallel
A back-to-back bend creates a U-shape with two 90-degree bends facing each other, resulting in two parallel vertical legs.
Question 2: According to the NEC, what is the maximum spacing for EMT conduit supports when run horizontally?
- 5 feet
- 10 feet (Correct answer)
- 12 feet
- 20 feet
Correct answer: 10 feet
NEC 358.30 requires EMT to be supported at intervals not exceeding 10 feet for horizontal runs.
Question 3: What is the primary purpose of a conduit expansion coupling?
- To allow rotation during installation
- To accommodate thermal expansion and contraction in long runs (Correct answer)
- To connect conduit of different diameters
- To provide a watertight seal at enclosures
Correct answer: To accommodate thermal expansion and contraction in long runs
Expansion couplings allow conduit to move axially as it expands and contracts with temperature changes, preventing buckling or stress.
Question 4: When pulling wire through a conduit that has multiple bends, which technique reduces friction?
- Pulling all conductors simultaneously
- Using wire pulling lubricant (wire lube) (Correct answer)
- Pre-heating the conduit
- Reducing conductor size by one gauge
Correct answer: Using wire pulling lubricant (wire lube)
Wire pulling lubricant significantly reduces friction between conductors and the conduit wall, especially through bends.
Question 5: Which conduit type is NOT permitted for direct burial without concrete encasement?
- Schedule 40 PVC (listed for direct burial)
- Rigid Metal Conduit (RMC)
- Intermediate Metal Conduit (IMC)
- EMT (Correct answer)
Correct answer: EMT
EMT is not listed for direct burial because its thin walls provide insufficient protection against soil corrosion and physical damage.
Question 6: When bending conduit for a four-bend saddle, the center two bends should each be:
- Equal to the two outer bends
- Half the angle of the outer bends (Correct answer)
- Twice the angle of the outer bends
- 45 degrees regardless of obstruction size
Correct answer: Half the angle of the outer bends
In a four-bend saddle, the outer bends are larger and the inner bends are half the outer angle, creating a symmetrical profile over the obstruction.
Question 7: What is the NEC requirement for conduit installed in a wet location regarding fittings?
- Standard fittings are acceptable if painted
- Fittings must be listed for wet locations (Correct answer)
- Only PVC conduit fittings are allowed
- Fittings must be stainless steel
Correct answer: Fittings must be listed for wet locations
NEC 314.15 and conduit-specific articles require that fittings in wet locations be listed and identified for use in wet locations.
CEA Conduit Bending and Installation 4
When bending a back-to-back (U-bend) in conduit, the second bend must be placed so that: