Written against the 2026 NEC and checked section by section, September 2026
Expansion Fittings and Deflection Practice Questions
An expansion fitting question is one of four shapes, and the first job is telling them apart. A calculated PVC or RTRC run works off a temperature change and a length against a quarter inch threshold, a structural joint takes a listed fitting with no arithmetic, a buried run coming out of the ground is an arrangement problem, and a metal raceway with a fitting in it turns into a bonding question in Article 250. These 25 work all four, with the table values used exactly as the 2026 edition prints them.
Pick an answer and the explanation opens with the section it comes from. These are original questions written for this site, not questions from the exam. Have your own code book open: the Texas exam is open book, and looking the section up is the skill being tested.
Read the expansion fittings and deflection study page first if the topic is new to you.
1. What amount of calculated length change puts an expansion fitting in a PVC run?
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B. One quarter of an inch
The section sets the threshold at 6 millimeters, a quarter of an inch, of expected length change in a straight run between securely mounted items. Below that no fitting is called for and at or above it one is. The figure is fixed and it does not move with trade size or with how long the run happens to be.
NEC 2026 352.44
2. For the PVC expansion rule, what marks the two ends of a straight run?
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D. Securely mounted items such as boxes, cabinets, elbows or other conduit terminations
The section names the ends of the run as securely mounted items and lists boxes, cabinets, elbows and other terminations as examples. An elbow counts, which cuts a lot of runs that look long on a drawing down to something shorter. Ordinary straps in the middle of a run are not the ends of it.
NEC 2026 352.44
3. Which of these does not feed the PVC expansion calculation?
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A. The trade size of the conduit
Three things decide the answer and trade size is not among them. Length and temperature change do the arithmetic, and the material picks which table you read. Support spacing does change with trade size, which is where the confusion usually starts.
NEC 2026 352.44, Table 352.44, Table 352.30(B)
4. A straight PVC run is 200 feet long and the temperature change it will see is 60 degrees Fahrenheit. Table 352.44 gives 2.43 inches per 100 feet at that change. What is the expected length change?
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C. 4.86 inches
The table figure is stated per 100 feet, so 200 feet doubles it and 2.43 becomes 4.86 inches. That is many times the quarter inch threshold, so a fitting goes in and the only open question is how much travel it needs. Leaving the answer at 2.43 means never scaling for the length of the run, which is the usual slip here.
NEC 2026 352.44, Table 352.44
5. A straight PVC run is 100 feet long and sees a 25 degree Fahrenheit change. The table gives 1.01 inches per 100 feet. Is a fitting called for?
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D. Yes, because 1.01 inches is well past the quarter inch threshold
One hundred feet takes the table figure straight across, so the movement is 1.01 inches and that is four times the threshold. The section sets no minimum run length and no minimum temperature change, so the first three answers describe conditions that do not exist. The only comparison made is the calculated movement against a quarter of an inch.
NEC 2026 352.44, Table 352.44
6. At a 30 degree Fahrenheit change, Table 352.44 gives 1.22 inches per 100 feet for PVC. About how long does a straight run have to be before a fitting is required?
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B. About 20 feet
Divide the quarter inch threshold by 1.22 inches per 100 feet and you get about 0.2 of a hundred feet, which is roughly 20 feet. That is shorter than most people expect, which is the argument for running the arithmetic rather than eyeballing the length. Halve the temperature change and the length that trips the threshold roughly doubles.
NEC 2026 352.44, Table 352.44
7. The informational note under the general expansion fitting sentence gives a nominal figure for steel conduit. How is it found?
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C. By multiplying the PVC table length change by 0.20
Steel moves roughly a fifth as much as PVC for the same temperature change, so the note says to take the PVC figure and multiply by 0.20. Aluminum gets 0.40, which is where the fourth option comes from. Both are notes rather than requirements, so they inform the judgment call in the general sentence instead of setting a threshold.
NEC 2026 300.9(B), Table 352.44
8. A steel conduit run is 100 feet long and sees a 100 degree Fahrenheit change. The PVC table gives 4.06 inches per 100 feet at that change. What is the nominal movement of the steel run?
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A. 0.81 inches
Multiply the PVC figure by 0.20 for steel and 4.06 becomes 0.81 inches over that 100 feet. The 1.62 inch answer applies the aluminum factor of 0.40 instead, and 4.06 leaves the PVC figure alone. Even at a fifth of the plastic movement the steel run is well past a quarter inch, which is why metal raceways get fittings too.
NEC 2026 300.9(B), Table 352.44
9. A reinforced thermosetting resin conduit run is 150 feet long. Table 355.44 gives 1.80 inches per 100 feet at the temperature change in question. What is the expected length change?
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D. 2.70 inches
One and a half times 1.80 is 2.70 inches, and the threshold and the method match the PVC rule exactly. RTRC gets its own article and its own table because its coefficient of thermal expansion is well under half that of PVC. Reading the PVC table for an RTRC run roughly doubles the answer.
NEC 2026 355.44, Table 355.44
10. Which table gives the length change for a reinforced thermosetting resin conduit run?
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C. Table 355.44
RTRC is covered by Article 355 and its expansion figures sit in Table 355.44 under the expansion section of that article. Table 352.44 belongs to PVC, and Table 352.30(B) is a PVC support spacing table that has nothing to do with movement. Picking the right article first is most of this question.
NEC 2026 355.44, Table 355.44, Table 352.44
Ten down. If you want these timed and scored by content area, the practice exam runs thirty questions free, and the full bank of 178 plus the calculation ladder is $79 once.
11. A raceway crosses a structural joint in a parking garage that the structure is designed to move at. What does the code require?
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A. A listed expansion or deflection fitting, or other approved means
The structural joint rule has no table behind it and no threshold to work out. The building is designed to move at that joint, so a raceway crossing it takes a listed fitting or another approved means. It reaches every raceway type, which is why twelve feet of EMT is caught by it while the same twelve feet away from a joint is not.
NEC 2026 300.6(H)
12. Which fact tells you that you are in the structural joint rule rather than the thermal expansion rule?
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B. The building is designed to move at the point the raceway crosses
The two rules are told apart by what moves. Thermal expansion is the raceway changing length, and it comes with a table and a quarter inch threshold. The structural joint rule is the building moving, and it asks for a listed fitting with no arithmetic at all, whatever the raceway is made of.
NEC 2026 300.6(H), 352.44
13. Beyond PVC and RTRC, what does the general wiring methods article say about expansion fittings?
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C. Raceways get expansion, expansion deflection or deflection fittings where necessary to compensate for thermal expansion, deflection and contraction
The general sentence reaches every raceway type and carries no number inside it. Where necessary is the whole of the test, and the informational note with the steel and aluminum factors is what gives you something to reason with. A candidate hunting for a threshold in this section will not find one.
NEC 2026 300.9(B)
14. A deflection fitting is installed in a metal raceway that also serves as the equipment grounding path. What else does the code require?
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D. That the fitting be made electrically continuous by equipment bonding jumpers or other means
A fitting that lets a raceway slide has broken the metal path fault current would otherwise take, so a rule in the grounding article puts a bonding jumper across it. The same sentence covers expansion fittings, expansion deflection fittings and telescoping sections of metal raceway. An answer that installs the fitting and stops has done half the job.
NEC 2026 250.98
15. Which article carries the requirement to bond across an expansion fitting in a metal raceway?
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B. Article 250
The bonding requirement for loosely jointed metal raceways sits in the grounding and bonding article rather than in any raceway article. That is why a scenario that reads like a raceway question is answered in Chapter 2. One installation reaching two chapters is a shape item writers like.
NEC 2026 250.98
16. Direct buried raceways and cables are subject to settlement or frost movement. What does the general wiring methods article ask?
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A. That they be arranged so the movement does not damage the conductors, the raceways or the connected equipment
The earth movement rule is an arrangement rule rather than a fitting rule, and it names damage to the conductors, to the raceways and to connected equipment as what has to be prevented. Its informational note points at S loops in the trench and at expansion fittings in risers to fixed equipment. Nothing in it prescribes a spacing or a depth.
NEC 2026 300.7(J)
17. On a direct buried run that comes out of the ground into fixed equipment, where does an expansion fitting do its work?
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C. Above grade on the riser, at the transition into fixed equipment
The soil moves and the buried run moves with it, so the joint under stress is the riser where it lands in something rigid. The informational note under the earth movement rule recognizes expansion fittings in raceway risers to fixed equipment for exactly that reason. A fitting down in the trench is not where the tearing happens.
NEC 2026 300.7(J)
18. PVC conduit is securely fastened within what distance of each box, conduit body or other termination?
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B. 3 feet
The securing subsection sets 3 feet from each outlet box, junction box, device box, conduit body or other conduit termination, unless the conduit is listed for something else. Support spacing between those points is a separate table that changes with trade size. Mixing the fastening distance with the support spacing is the usual error.
NEC 2026 352.30, Table 352.30(B)
19. Trade size 2 PVC is run horizontally. What is the maximum spacing between supports?
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D. 5 feet
The support table groups trade sizes 1-1/4 through 2 at 5 feet, with 1/2 through 1 at 3 feet and 2-1/2 through 3 at 6 feet. Spacing grows with trade size on this table, which is the opposite of the expansion calculation where trade size never appears. Both facts live in the same article a couple of pages apart.
NEC 2026 Table 352.30(B), 352.30
20. A long exposed PVC run has a correctly sized expansion fitting, and the conduit is strapped down hard at every support on both sides of it. What is wrong?
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A. The securing section asks that PVC be fastened so movement from thermal expansion and contraction is permitted
The securing section opens by saying PVC is fastened so that movement from thermal expansion or contraction is allowed to happen. Clamp both sides down and the fitting is decoration while the movement goes back into the terminations. Bonding belongs to metal raceways, so that option is answering a different scenario.
NEC 2026 352.30
21. A PVC run goes from 35 degrees Fahrenheit in winter to 115 degrees in summer. What temperature change goes into the table?
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B. 80 degrees
The table column is a change, so you subtract the two extremes rather than reading either one of them. One hundred fifteen less thirty five is 80 degrees. Reaching for an endpoint gives a figure that looks reasonable and is wrong, and both endpoints are sitting on the sheet for that reason.
NEC 2026 352.44, Table 352.44
22. PVC conduit is not used where the ambient temperature exceeds what, unless it is listed otherwise?
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C. 50 degrees Celsius
The uses not permitted section stops at 50 degrees Celsius, which is 122 degrees Fahrenheit, unless the conduit carries a listing for more. That is an ambient limit on the material and it is separate from the expansion calculation, which runs on a change rather than on a temperature. Both facts sit in Article 352 and both get asked.
NEC 2026 352.12
23. A raceway passes from a heated interior to a cold exterior and condensation is known to be a problem. What does the code ask for?
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A. That the raceway or sleeve be sealed against warm air circulating to the colder section, or another approved means be used
This is the other half of the section that holds the general expansion sentence, and it is about air rather than about movement. Sealants identified for use with the conductors, or a listed fitting such as a thermal break coupling, are what it names. Drain holes and added insulation are field practices rather than what this subsection asks for.
NEC 2026 300.9
24. An item describes a metal raceway crossing a building expansion joint, with four options about jumpers and fittings. Where is it answered?
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D. In the structural joint rule for the fitting and in the grounding article for the jumper
Two sentences in two chapters answer that one scenario. The listed fitting comes from the structural joint rule, and the jumper across it comes from the loosely jointed metal raceway rule in the grounding article. The PVC expansion table never enters it, because nothing in the stem is about the raceway changing length.
NEC 2026 300.6(H), 250.98
25. Why do the expansion tables sit in the nonmetallic conduit articles rather than in the metal ones?
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A. Nonmetallic conduit expands several times as much as steel for the same temperature change
The coefficient printed at the top of the PVC table is several times that of steel, so the movement that matters shows up first in the plastic. Steel raceways are still covered by the general sentence in the wiring methods article, and the note there gives the factor for converting the PVC figure. Nothing in the code exempts a metal raceway from expansion rules.
NEC 2026 352.44, 300.9(B)
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