Written against the 2026 NEC and checked section by section, September 2026
Feeders Practice Questions
Article 215 is short, and most of a feeder question is answered somewhere else. What genuinely lives here is the minimum rating and size, the overcurrent device, ground fault protection of equipment, identification and a handful of small rules, and the two sections that carry the work both changed numbers for the 2026 edition. These 25 items work the 125 percent increase where it applies, the classification questions that need one sentence out of Article 100, and the motor sum in Article 430 that replaces the general approach.
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 feeders study page first if the topic is new to you.
1. Where does a feeder end?
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D. At the final branch circuit overcurrent protective device
The Article 100 definition sets both ends, a source at the top and the final branch circuit overcurrent protective device at the bottom. Not any overcurrent device, the final one in the branch circuit sense, so a supplementary device inside a piece of equipment does not end a feeder. Conductors ahead of the service disconnect are service conductors and belong to Article 230.
NEC 2026 Article 100
2. Which of these runs is a feeder?
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B. Transformer secondary to the first panelboard
The definition names the source of a separately derived system as an upstream end, so conductors from a transformer secondary to the first panelboard are feeder conductors. Service point to service disconnect is service territory under Article 230. The other two runs sit on the load side of a final branch circuit device, which makes them branch circuit.
NEC 2026 Article 100
3. A feeder supplies 96 amperes of continuous load and 30 amperes of noncontinuous load. Which statement about the 125 percent multiplier is right here?
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A. It reaches the 96 amperes only, giving 120, which is then added to the 30
The multiplier reaches the continuous portion and nothing else, so 96 becomes 120 and the noncontinuous 30 amperes goes in untouched. The conductor then needs 150 amperes of ampacity. Running the multiplier over the whole 126 amperes gives 157.5, which is the answer for anyone who applies it too broadly.
NEC 2026 215.4
4. On that same feeder, what is the minimum rating of the overcurrent device?
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C. Not less than 150 amperes
The article states the increase twice, once for the conductor and once for the device, and both work out to the noncontinuous load plus 125 percent of the continuous load. That is 150 amperes here, and 150 happens to be a standard rating already. An option that moves the conductor and leaves the device sitting at the plain load has done half the job.
NEC 2026 215.5, 215.4, 240.6(A)
5. One stem asks for the calculated feeder load and another asks for the minimum feeder conductor. Why do the two answers differ?
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B. Because the load calculation article does not apply a 125 percent multiplier to continuous loads, while the feeder sizing rule does
The load calculation article says plainly that a load calculation is not required to run continuous loads at 125 percent. That multiplier lives in the conductor and device rules instead. The gap between the two answers is exactly a quarter of the continuous portion, and an item can ask for either one.
NEC 2026 120.5, 215.4, 215.5
6. The general subsection of the minimum size rule says feeder conductor ampacity is the larger of two figures. What is the second one?
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A. The maximum load to be served after correction and adjustment factors are applied
One figure is the continuous load treatment and the other is the plain load carried through correction for ambient and adjustment for conductor count. You work both and take the larger, and the same subsection then sends you to the termination temperature rule. Candidates who work only the continuous figure get caught on a hot or crowded run.
NEC 2026 215.4, 310.14, 110.14(C)
7. A feeder assembly, including its overcurrent devices, is listed to run at 100 percent of its rating. What relief does Article 215 give?
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D. The conductor ampacity and the device rating may be the plain sum of continuous and noncontinuous load
Both the conductor rule and the device rule carry the same relief for equipment listed to run at 100 percent of its rating, and it drops the 125 percent multiplier on the continuous portion. It is a listing based permission, so the stem has to say the assembly is listed for it. Nothing about the grounding conductor changes.
NEC 2026 215.4, 215.5
8. A feeder carries the total load supplied by service conductors whose ampacity is 50 amperes. What does the article require of the feeder conductors?
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C. That their ampacity be not less than that of the service conductors
A short subsection says that where a feeder carries the whole load supplied by service conductors rated 55 amperes or less, the feeder ampacity is at least the service conductor ampacity. It bites only on small services, which is why it goes unread. Above 55 amperes the subsection simply does not apply.
NEC 2026 215.4
9. What sets the floor on the size of a feeder grounded conductor?
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A. It is not smaller than the equipment grounding conductor size Table 250.122 requires for that feeder
The minimum size section points the grounded conductor at the equipment grounding conductor table read at the feeder device rating, then says the parallel subdivision of that section does not apply where grounded conductors are run in parallel. Table 250.66 is the electrode conductor table and answers a different question. A full size neutral is often installed and is not what the rule asks for.
NEC 2026 215.4, Table 250.122, 250.122
10. In the 2026 edition, which section holds Minimum Rating and Size for feeders?
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B. 215.4
Minimum Rating and Size sits at 215.4 in the 2026 edition and Overcurrent Protection sits at 215.5. Both of those numbers held other content in the previous edition, so a tab set for the older book lands you on real code text answering a different question. Finding the subsection by its title is the safer habit.
NEC 2026 215.4, 215.5
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. Ground fault protection of equipment reaches a feeder disconnect on a solidly grounded wye system when the disconnect is rated at least what?
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C. 1000 amperes
The trigger is a disconnect rated 1000 amperes or more on a solidly grounded wye system of more than 150 volts to ground and not over 1000 volts phase to phase. All three conditions have to hold together, so a 1200 ampere disconnect on a 208Y/120 volt system escapes it, because 120 volts to ground is not more than 150. The protection itself is then installed under the service rules.
NEC 2026 215.10
12. What did the 2026 edition add to the feeder ground fault protection of equipment section?
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D. A parallel subsection for solidly grounded dc systems above 150 volts to ground and not above 1500 volts line to line
The section gained a second subsection mirroring the ac rule for solidly grounded dc systems, using the same 1000 ampere disconnect threshold. Its ceiling is 1500 volts line to line rather than 1000 volts phase to phase, which matches how the code treats dc elsewhere in this edition. The three exceptions read the same way under both.
NEC 2026 215.10
13. A temporary feeder connects a generator to a facility for emergency repairs. What does the ground fault protection of equipment section allow?
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A. The protection is not required, for the time needed and not beyond 90 days
One of the three exceptions lets temporary feeders for repair, maintenance or emergency generator connections go without ground fault protection of equipment, and it caps the relief at 90 days. The other two cover a continuous industrial process and the case where the protection already exists upstream. Nothing in the exception touches the grounding conductor.
NEC 2026 215.10
14. When does the feeder identification rule ask for each ungrounded conductor to be identified by phase or line and by nominal voltage system?
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B. Where the premises wiring system has feeders supplied from more than one nominal voltage system
The trigger is written about the premises wiring system rather than about the one feeder in front of you. A single 480Y/277 volt feeder in a building that also runs 208Y/120 volts is caught by it, even though that feeder on its own is not ambiguous. The identification then goes on at every termination, connection and splice point.
NEC 2026 215.12
15. Under the feeder identification rule, what has to happen with the method that was used?
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D. It is documented so it stays readily available, or permanently posted at each panelboard or similar distribution equipment
The subsection asks for the identification method to be written down and kept available, or posted at the equipment the conductors originate from. Color coding, marking tape, tagging or another approved means all satisfy the identification itself. The posting is the half candidates forget, and it is the half that makes the scheme usable years later.
NEC 2026 215.12
16. What does the feeder diagram section ask for, where the authority having jurisdiction requires a diagram?
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C. The area served, the calculated load before and after demand factors, the demand factors used, and the size and type of conductors
The section lists what the diagram contains, and every item on that list comes out of the load calculation. It is conditional on the authority having jurisdiction asking for it, so it is not a universal submittal requirement. Voltage drop appears as an informational note elsewhere in the article and is not on this list.
NEC 2026 215.13
17. How many sets of 3-wire feeders may share one common neutral conductor?
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A. Up to three
The common neutral section allows up to three sets of 3-wire feeders, or two sets of 4-wire or 5-wire feeders, on one common neutral. It also asks that everything sharing that neutral run in the same raceway or enclosure where a metal one is used. In the 2023 book this content sat at 215.4, which is now the minimum size rule.
NEC 2026 215.14
18. What does Article 215 say about ground fault circuit interrupter protection on a feeder?
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D. A listed device in a readily accessible location on the feeder is permitted in place of the protection the branch circuit rules would otherwise call for
This one is a permission rather than a requirement. Protecting the feeder with a listed ground fault circuit interrupter, installed where it can be reached, may stand in for the protection the branch circuit section and the temporary wiring section ask for downstream. It changes where the device sits rather than whether protection exists at all.
NEC 2026 215.9, 210.8
19. A 460 volt three phase feeder supplies a 25 horsepower motor at 34 amperes, a 10 horsepower motor at 14 amperes and a 5 horsepower motor at 7.6 amperes. What minimum conductor ampacity does the motor rule call for?
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B. 64.1 amperes
The motor rule takes 125 percent of the largest motor full load current and adds the full load currents of the others at 100 percent, so 42.5 plus 14 plus 7.6 gives 64.1 amperes. Adding all three plainly gives 55.6, and running 125 percent across all three gives 69.5. This sum replaces the general feeder approach rather than being added on top of it.
NEC 2026 430.24
20. That same feeder also carries 20 amperes of continuous lighting load. What does the motor rule add for it?
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C. 25 amperes
The rule has four terms and the last one is 125 percent of the continuous non motor load, so 20 amperes of continuous lighting enters as 25. Noncontinuous non motor load enters at 100 percent under the third term. Added to the 64.1 amperes of motor load, the feeder comes to 89.1 amperes.
NEC 2026 430.24
21. When may feeder conductors for a group of motors be smaller than the motor rule calls for?
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A. Where reduced conductor heating results from duty cycle or from motors not all running at once, and the authority having jurisdiction grants permission
The demand factor section is written as a permission the authority having jurisdiction can grant, and the condition is reduced conductor heating from duty cycle, intermittent operation, or motors that do not all run together. The conductors still have to carry the maximum load that actually occurs. Nothing in it turns on run length or on insulation rating.
NEC 2026 430.26, 430.24
22. A stem gives a dwelling floor area and a list of appliances and asks for the feeder load. Which article answers it?
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D. The load calculation article, which is Article 120 in the 2026 edition
Article 215 sets the target and says almost nothing about how the load is arrived at. The calculation itself, with its general lighting figure and its demand factors, comes out of the load calculation article. Article 310 then converts the answer into a conductor and Article 240 protects it.
NEC 2026 215.4, 120.5
23. Where does the feeder article require barriers?
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B. So that no energized uninsulated ungrounded busbar or terminal is exposed to inadvertent contact while load terminations are serviced in equipment supplied by feeder taps or transformer secondary conductors, with the disconnect open
The barrier rule targets the case where opening the disconnect in front of you leaves the supply side of that equipment live, which is exactly what feeder taps and transformer secondary conductors produce. It names panelboards, switchboards, switchgear and motor control centers. It is not a blanket requirement covering all panelboards.
NEC 2026 215.15, 240.21(B)
24. A feeder supplies distribution equipment whose branch circuit devices serve dwelling units. What does the 2026 feeder article require?
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C. A Type 1 or Type 2 surge protective device in or next to that distribution equipment
The surge protection section lists dwelling units first among the occupancies it reaches, along with dormitories, guest rooms and certain sleeping areas. The device goes in or adjacent to the distribution equipment on the load side of the feeder, and it carries a nominal discharge current rating of at least 10 kA. Replacing that equipment brings the whole section back into play.
NEC 2026 215.18
25. What voltage range does Article 215 cover?
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A. Feeders not over 1000 volts ac or 1500 volts dc
The scope section stops at 1000 volts ac and 1500 volts dc and sends anything above that to a separate article. Those two ceilings show up again and again through the 2026 edition, which makes them worth carrying as a pair. An option built on 600 volts belongs to editions well before this one.
NEC 2026 215.1
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