Texas Electrician ExamTexas journeyman & master

Checked against primary sources 2026-08-24

A conduit body is an enclosure, and it is not sized like a box

Three different methods can size the same enclosure, and which one applies turns on conductor size and on whether anything is spliced inside it.

On this page
  1. What an enclosure item can ask you
  2. Where the code wants an enclosure
  3. A conduit body is an enclosure in its own right
  4. The sizing rules, and how to tell which one you are in
  5. What the pull point method actually measures
  6. Support, and the splice that does not change it
  7. Accessible means accessible afterward
  8. Deep enough, and strong enough
  9. Working an enclosure item under the clock
  10. What this page cites

What an enclosure item can ask you

Box fill is a counting exercise before it is ever an arithmetic one, and the grounding conductor count is not what most people remember Each conductor that originates outside the box and terminates or is spliced inside counts once, and so does each conductor that passes through without splice or termination. Up to four equipment grounding conductors together take one volume allowance, and each one beyond four takes a quarter allowance. All internal cable clamps together take one. Each yoke or strap holding a device takes a double allowance. Each terminal block assembly takes one. Small fittings such as locknuts and bushings take nothing. The counts are then multiplied by the volume for the wire size, which is in the code book. device box, cut away each conductor that terminates inside, or passes straight through 1 each equipment grounding conductors, up to four of them together 1 total every one after the fourth ¼ each all internal cable clamps 1 total each yoke or strap with a device 2 each each terminal block assembly 1 each locknuts, bushings, small fittings 0 count × the volume for that wire size the volume comes out of your book, not off this page the quarter allowance is the one people miss
Get the count right and the arithmetic is trivial. Almost every miss is a count, not a multiply. Drawn against NEC 314.16(B)(1) through (B)(6). The volumes are in the allowance table printed with 314.16(B), in your book. We do not print its subdivision number here: NFPA code-making panel 8 first revisions 7525 and 7527 quote it as Table 314.16(B)(1) and data/nec2026-art314.js recorded it as Table 314.16(B)(4) from a read of the page, and that is unresolved.

One box on one drawing generates three separate items, and they are answered from three separate places.

Candidates prepare for the middle one and get caught by the other two. The middle one is arithmetic and every study guide covers it. The other two are read-the-sentence questions, and they are cheaper to get right.

Where the code wants an enclosure

Article 300 carries the general answer: a box, conduit body or fitting goes at every conductor splice, at every outlet, at every switch point, at every junction, at every termination and at every pull point, unless something in the code says otherwise. In the 2026 book that is NEC 300.17, which was 300.15 in the edition before it.

The exceptions are the tested part. Several wiring methods carry their own permission to make a connection without a box, some equipment enclosures count as the box, and some listed assemblies are the enclosure. An item is usually built by describing an installation with no box in it and asking whether that is acceptable, which means the answer sits in an exception rather than in the general rule.

One of those exceptions is worth reading in place because it answers the does-it-have-to-be-a-box half of the question directly. A fitting identified for the use stands in for a box or a conduit body where no conductor is spliced or terminated inside the fitting, and where the fitting serves as a pull point it stays accessible after installation (NEC 300.17). Nothing spliced, nothing landed, and you can still get at it.

The related sentence people forget is about conductors left at the enclosure. A length of free conductor is left at every box for making up the connection, and it is measured from where the conductor emerges from its raceway or cable sheath rather than from the edge of the box. The 2026 book puts that at 300.16, and the box fill rules point at it by number when they explain how to count a long loop (NEC 314.16).

A conduit body is an enclosure in its own right

The heading over the fill rules names boxes and conduit bodies together, and the first sentence under it treats them the same way: both are of a size that gives free space to everything inside (NEC 314.16).

That is why a conduit body can be the answer to a pull point question. It is not a lesser thing that happens to be permitted. It is an enclosure with its own sizing rules.

What separates it from a box is what you are allowed to do inside it, and what changes when you do it. Put a splice in a conduit body and you have changed which arithmetic sizes it and you have added a marking requirement. You have not changed how it is allowed to be held up, and that last point is where most of the wrong answers on this topic come from.

The sizing rules, and how to tell which one you are in

This is the part people get wrong, and it is a clean decision rather than a judgment call.

Conductors 6 AWG and smaller, nothing spliced

A conduit body used purely as a pull point, with the conductors passing straight through, is sized against the raceway rather than against the conductors. Two comparisons, and both of them come from conduit fill rather than from volume: the cross-sectional area of the conduit body against the cross-sectional area of the largest conduit or tubing it can be attached to, and the number of conductors against what Chapter 9, Table 1 allows in that conduit (NEC 314.16). The section states the multiple for the area. There is no cubic inch total anywhere in this branch and no conductor count in the box fill sense.

Conductors 6 AWG and smaller, with splices, taps or devices inside

Now the volume rules come in on top, and the gate is a marking. Only a conduit body that its manufacturer has durably and legibly marked with its volume is permitted to contain a splice, a tap or a device, and once it contains one the conductor count comes from the box fill calculation (NEC 314.16). If a scenario describes a splice in a conduit body and gives you no marked volume, the marking is the answer the item is fishing for.

The area comparison does not disappear when the splice arrives. It is the floor. Box fill is added to it, not substituted for it.

Short radius conduit bodies, which are a different animal

A capped elbow or a service entrance elbow that encloses 6 AWG or smaller and exists only to let you install the raceway and pull the conductors through it does not get a splice, a tap or a device at all, whatever it is marked with. It gets sized to give free space to the conductors in it and nothing more (NEC 314.16). An item describing a splice made up inside a service entrance elbow is describing a violation, not a sizing problem, and the volume marking is a distractor in that scenario rather than the answer.

Conductors 4 AWG or larger, either way

Boxes and conduit bodies enclosing conductors 4 AWG or larger also comply with NEC 314.28, which is a different method again. Box fill does not size these. Geometry does.

So the first fork is conductor size and it is sharp. There is no trade size between 6 AWG and 4 AWG, so nothing sits in the gap and there is no judgment to make. The second fork, taken only on the 6 AWG and smaller branch, is whether anything is spliced, tapped or mounted inside.

What the pull point method actually measures

NEC 314.28 sizes a pull or junction enclosure from the trade size of the raceway entries rather than from what is in them. The reason is mechanical. A large conductor has a bending radius, and the enclosure exists to give you room to make that bend without damaging the insulation.

The method has two cases and they are measured differently. A straight pull is measured from the wall where the raceway enters to the opposite wall of the enclosure. An angle pull, a U pull or a splice is measured from each raceway entry to the opposite wall, and there is a further distance required between two entries that carry the same conductor. Each case is a multiple of the largest raceway trade size, the multiple is different for each case, and both multiples are printed in the section.

Two habits pay here. Sketch the enclosure with its raceways before calculating anything, because the case follows from the picture rather than from the wording. And check whether the item wants the enclosure dimension or the distance between two entries, since the section gives both and the wrong one is always among the options.

Support, and the splice that does not change it

A conduit body can be carried by the raceways that enter it, and putting a splice inside it does not take that permission away. This is the single most common wrong belief on this topic, including in study material, so it is worth getting the line in the right place.

The line in NEC 314.23 is not spliced against unspliced. It is device against no device. NEC 314.23(E) governs an enclosure that holds no device other than splicing devices and supports no luminaire, lampholder or other equipment. Wire connectors and other splicing devices sit on that side of it. The conditions that come with it are a ceiling on the size of the enclosure, threaded entries or hubs identified for the purpose, two or more conduits threaded wrenchtight into the enclosure or its hubs, and each of those conduits secured within a stated distance of the enclosure, with a shorter distance where every entry is on the same side (NEC 314.23(E)).

Then comes the exception that decides most conduit body items. A conduit body no larger in trade size than the largest conduit or tubing attached to it can be supported by a single raceway, with one entry or more, and the exception names which raceway types qualify (NEC 314.23(E)). Read that list in your own book, because the 2026 edition widened it and widened what else the exception covers.

NEC 314.23(F) is the other side of the line. Put a device in the enclosure that is not a splicing device, or hang a luminaire or a lampholder off it, and the securing distance for the entering conduits tightens and the single-raceway exception narrows to fewer raceway types (NEC 314.23(F)). Same enclosure, same raceway, different answer, because of what is mounted inside.

What the splice does change is the fill section. It adds the volume marking and the box fill count, and it adds a sentence that conduit bodies are supported in a rigid and secure manner (NEC 314.16). That sentence is about the quality of the support. It is not a ban on the raceway providing it, and the way a conduit body ordinarily satisfies it is the 314.23(E) exception.

So the exam version is short. Splice in a conduit body: check the volume marking, then size it by box fill. Support: still 314.23, still permitted on the raceway, and the question that moves it to the stricter subsection is a device or a luminaire, not a splice.

Accessible means accessible afterward

Article 314 keeps boxes and conduit bodies reachable without taking the building apart. Not reachable at rough-in. Reachable after the drywall, the ceiling and the paint.

The test is about the wiring inside the enclosure, not about whether you can see the cover from across the room, and it is written against the building rather than against the installer. If getting to the conductors means removing part of the structure or the finish, the enclosure is not accessible.

The scenarios write themselves and the exam uses all of them: a junction box sheeted over, a conduit body behind a permanent architectural panel, a splice in a space nobody can reach. Underground enclosures are handled separately from the general rule, so read what sits under it in your own copy before you mark a buried installation as a violation. The general sentence alone will send you to the wrong answer there.

Deep enough, and strong enough

An enclosure that passes the fill calculation can still be the wrong enclosure.

Outlet and device boxes also comply with NEC 314.24, which sets a minimum depth keyed to the largest conductor entering the box and adds a separate rule for equipment that projects backward out of the mounting plane by more than a stated amount. A shallow box with a deep device in it fails on depth while passing on volume, and a scenario that mentions a device projecting into the box is pointing at that section rather than at the fill rules.

Weight is the other one. A box carrying a luminaire or a ceiling-suspended paddle fan is governed by the thresholds in NEC 314.27, and the section handles the two objects differently and marks some cases by what the box is listed for rather than by a fixed figure. Read which object the scenario describes before you reach for a number.

One more sentence worth reading in place: the fill rules do not reach terminal housings supplied with motors or generators (NEC 314.16). A motor scenario that looks like a box fill problem is often not one.

Working an enclosure item under the clock

  1. Decide what the item is asking: whether an enclosure is needed, whether this one is big enough, or whether it is installed acceptably.
  2. If it is a size question, find the largest conductor in the enclosure. That single fact chooses your method.
  3. Four AWG or larger sends you to 314.28 and to a sketch. Six AWG and smaller keeps you in 314.16.
  4. For a conduit body on 6 AWG and smaller, ask whether anything is spliced, tapped or mounted inside. Nothing inside means the raceway comparison alone. Something inside means the volume marking and box fill on top of it, and a short radius body means the installation is wrong before you calculate anything.
  5. If the item is about support, ask what is mounted in the enclosure rather than whether it is spliced, because that is the question 314.23 turns on.
  6. Before you commit, check depth and accessibility, because an item will sometimes give you a correctly sized box that fails on one of those.

Enclosures are a steady share of the wiring methods and materials items, and that area supplies ten of the fifty-six scored questions on the journeyman knowledge portion. The sizing method you pick decides the answer before any arithmetic starts.

What this page cites

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