CEA Conduit Bending and Installation Questions and Answers — Questions and Answers
Question 1: An apprentice needs to make a 90-degree stub-up bend on a piece of 1/2-inch EMT. The desired stub height is 12 inches. The bender being used has a "take-up" of 5 inches. Where should the apprentice make their mark on the conduit to begin the bend?
- At 5 inches from the end of the conduit.
- At 12 inches from the end of the conduit.
- At 7 inches from the end of the conduit. (Correct answer)
- At 17 inches from the end of the conduit.
Correct answer: At 7 inches from the end of the conduit.
To achieve a desired stub-up height, the bender's take-up value must be subtracted from the desired height. The resulting measurement is where the mark is placed on the conduit. In this case, 12 inches (desired height) - 5 inches (take-up) = 7 inches. The bender's arrow is then aligned with this 7-inch mark to start the bend.
Question 2: According to the National Electrical Code (NEC), what is the maximum total degrees of bend permitted in a single run of conduit between two pull points, such as boxes or conduit bodies?
- 180 degrees
- 270 degrees
- 360 degrees (Correct answer)
- 450 degrees
Correct answer: 360 degrees
The NEC limits the total number of bends in a conduit run to 360 degrees between pull points. This is equivalent to four 90-degree bends. This rule exists to prevent damage to wire insulation from excessive friction and pulling force during installation.
Question 3: An apprentice has just cut a piece of EMT with a hacksaw. Which of the following describes the primary reason for reaming the inside of the conduit before installation?
- To create a sharper edge for better connector grip.
- To remove sharp edges that could damage wire insulation. (Correct answer)
- To slightly increase the conduit's internal diameter.
- To clean the outside surface for better paint adhesion.
Correct answer: To remove sharp edges that could damage wire insulation.
Cutting metal conduit leaves sharp burrs and edges on the inside. Reaming (or deburring) smooths these edges. This is a critical step to prevent the sharp metal from stripping, scraping, or otherwise damaging the insulation of the conductors as they are pulled through the conduit.
Question 4: When creating a standard 3-point saddle bend to cross over a small obstruction, what is the typical relationship between the center bend angle and the two outer bend angles?
- All three bends are made at the same angle.
- The center bend is half the angle of the two outer bends.
- The outer bends are one-third the angle of the center bend.
- The center bend is double the angle of the two outer bends. (Correct answer)
Correct answer: The center bend is double the angle of the two outer bends.
A standard 3-point saddle bend is most commonly made with a 45-degree bend at the center of the obstruction, and two 22.5-degree bends on either side. This makes the center bend's angle double the angle of each of the two outer bends.
Question 5: An apprentice is inspecting a long run of conduit with several offsets and notices a 'dog leg' in one of the bends. What does this term describe?
- A bend that exceeds the maximum allowable angle.
- A split or crack in the conduit wall from over-bending.
- Two or more bends that are not in the same plane, creating a twist. (Correct answer)
- A 90-degree bend that is slightly more than 90 degrees.
Correct answer: Two or more bends that are not in the same plane, creating a twist.
A 'dog leg' is a common bending flaw where multiple bends in a single run, like an offset, are not aligned on the same plane. This creates a crooked or twisted appearance in the conduit run instead of a straight, clean line.
Question 6: An apprentice is tasked with creating a 6-inch offset using 30-degree bends. Using the standard multiplier for a 30-degree bend, what is the required distance between the two bend marks?
- 6 inches
- 8.5 inches
- 12 inches (Correct answer)
- 15 inches
Correct answer: 12 inches
The standard multiplier for a 30-degree offset bend is 2.0. To find the distance between the bends, you multiply the offset depth by the multiplier. Therefore, 6 inches (offset depth) x 2.0 (multiplier) = 12 inches.
