CEA Conduit Bending and Installation 2 — Questions and Answers
Question 1: What is the minimum bend radius for 1-inch EMT conduit according to the NEC?
- 3.5 inches
- 4 inches
- 5 inches
- 6 inches (Correct answer)
Correct answer: 6 inches
The NEC requires a minimum bend radius of 6 times the internal diameter for 1-inch EMT, which equals approximately 6 inches at the inside of the bend.
Question 2: When making an offset bend in conduit, the two bends must be made in:
- Opposite directions in the same plane (Correct answer)
- The same direction in parallel planes
- Opposite directions in parallel planes
- The same direction in the same plane
Correct answer: Opposite directions in the same plane
An offset consists of two equal bends made in opposite directions in the same plane, creating a parallel shift in the conduit run.
Question 3: What tool is used to check that a conduit bend is a true 90 degrees?
- Torpedo level
- Combination square
- Speed square
- Any of the above (Correct answer)
Correct answer: Any of the above
A torpedo level, combination square, or speed square can all be used to verify a 90-degree bend is accurate.
Question 4: What is the purpose of applying a 'gain' calculation when bending conduit stubs?
- To add extra length for coupling connections
- To account for the conduit shortening through the bend arc (Correct answer)
- To allow for thermal expansion
- To compensate for wall thickness
Correct answer: To account for the conduit shortening through the bend arc
Gain is the amount the conduit effectively shortens at the outside of a bend arc, and it must be subtracted from the mark-to-end measurement.
Question 5: Which type of conduit bender is most appropriate for bending large-diameter rigid conduit (2 inches and above)?
- One-shot mechanical bender
- Chicago-style hand bender
- Hydraulic bender (Correct answer)
- Ratchet bender
Correct answer: Hydraulic bender
Hydraulic benders provide the force needed to bend large-diameter rigid conduit without kinking or flattening.
Question 6: When installing conduit through a fire-rated wall, what is required at the penetration?
- A conduit seal fitting
- Fire-rated caulk or a listed firestop system (Correct answer)
- An expansion fitting
- A grounding bushing
Correct answer: Fire-rated caulk or a listed firestop system
NEC 300.21 requires openings in fire-rated assemblies to be firestopped with listed materials to maintain the fire rating.
Question 7: What is the maximum number of quarter-bend equivalents (360 degrees total) 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
NEC 358.26 (and similar sections) limits conduit runs to a maximum of 360 degrees of bends between pull points, equivalent to four 90-degree bends.
CEA Conduit Bending and Installation 2
What is the minimum bend radius for 1-inch EMT conduit according to the NEC?