Conduit fill on the Texas journeyman exam, and the notes under Chapter 9 Table 1 that decide the answer

What the Texas exam asks here

Our question bank holds 500 Texas journeyman items and 51 of them sit in the conduit and raceways area. Twenty-seven of those work the raceway fill comparison itself, and two more reach it from the underground side, where a wet location forces a conductor type with a different area and the pull has to be checked again.

The items take three shapes. Some hand you a pull and a raceway and ask whether it fits. Some hand you a raceway and one conductor size and ask how many go in. Some hand you a mixed pull and ask for the total conductor area alone. Nine of the 27 print decimal areas in the stem, and four sit in the top difficulty tier.

On the published PSI content outline, wiring methods and materials carries 10 of the 56 scored items on the journeyman NEC knowledge portion and 2 of the 24 scored items on the calculations portion, so fill lands on both halves of the paper. Those halves run on separate clocks: 130 minutes across the 59 items you sit on knowledge, and 110 minutes across the 26 on calculations, which is about 2.2 and about 4.2 minutes an item. Using the code book and exam day covers how that split is published.

The two areas being compared

Conduit fill is one comparison. Total the cross-sectional area of every conductor in the raceway, then set that total against a permitted percentage of the raceway internal area. Both sides are areas, and the exam leans on that. One bank item sits at the easiest tier and still catches people: a conductor of twice the diameter takes four times the area, so working in diameters understates a full pull badly.

Everything inside the raceway occupies area whatever it carries. A bare equipment grounding conductor goes into the total at its own dimensions, and that same conductor stays outside the count driving the adjustment factors. A top-tier item moves a pull from 0.404 to 0.4174 square inches against a permitted 0.406 with one bare grounding conductor, so the fill fails while the adjustment count holds at twelve. Conductor sizing and ampacity carries that second count.

Length stays outside the calculation, and the same pull gives the same result at 40 feet and at 140 feet. Where you want the table lookups and the divisions set out line by line, the worked arithmetic is in its conduit fill page.

Three rows, and which one applies

Chapter 9, Table 1 sets the permitted percentage from the conductor count alone, in three cases: one conductor, two conductors, and more than two. The middle one costs marks, because the two-conductor case is the tightest of the three. Read both of the smaller-count figures in your own book, since two round conductors jam in a round raceway in a way that three or more do not.

The count stops mattering once the third conductor goes in. One item adds a fifth conductor for a separate circuit and asks which row applies now, and the answer is the row that already applied at four, since circuits have never been what these rows count.

A multiconductor cable counts as one conductor, taken on its own overall dimensions, and on the major diameter where the section is elliptical. One cable is therefore the single-conductor case, which is the most generous row on the table, while two cables drop you into the tightest one, and the bank builds two separate items on that reversal.

The nipple allowance and its two conditions

A conduit or tubing nipple of 24 inches or less, installed between boxes, cabinets and similar enclosures, is permitted 60 percent of its total internal area, and the same note switches off the conductor count adjustment factors. Both conditions hold together, or the ordinary allowance governs. One item gives you an 18 inch piece running from an enclosure to a coupling and on into a longer run, where the length passes and the location fails, so the ordinary allowance governs the whole run.

Know what the allowance is worth before you go hunting for it. At one conductor size, 60 percent against the ordinary 40 percent is half again as many conductors through the same pipe, so a run that takes eight becomes a nipple that takes twelve. An item that stretches that nipple to 30 inches moves the answer by four conductors.

The two reliefs in the note run on different conditions, and a top-tier item is built on that. A 20 inch length between two enclosures carrying ten current-carrying conductors collects both, since the fill allowance needs the length and the location together while the adjustment relief turns on the length alone. Move that same piece somewhere it reaches only one enclosure and it keeps the adjustment relief and gives up the larger fill share.

The rounding note and Annex C

On a how-many-fit item you divide the permitted area by the area of one conductor and get a decimal. Ordinarily you drop it, since a partial conductor cannot be pulled. The note under Table 1 carves out one case: where every conductor in the raceway is the same size, a decimal of 0.8 or larger carries the count up to the next whole number, so a division landing on 8.83 gives nine.

Same size means the same total area with the insulation counted, which is a stricter test than the same AWG number. One wire size in two insulation types looks uniform and fails that test, and so does a pull carrying a smaller grounding conductor. A candidate who has just learned the 0.8 rule and applies it everywhere has traded one wrong answer for another.

Annex C carries finished conductor counts for raceways filled with a single size and a single type, and it closes at the same boundary, since it was built by running that note. Items mix sizes deliberately to shut that door. One item goes further and applies the rounding note to an area overage of 0.4102 against 0.4000 permitted, which stacks two errors: the note governs a count in a uniform pull, and those sizes were mixed anyway.

Where the wrong answers come from

Every item in the bank carries a line on each wrong option naming the mistake that produces it. Collected across the 27 fill items, the same handful of errors keeps returning.

Two habits run through that list. One is real arithmetic done on the wrong pair of numbers, which is why labeling each figure before you divide earns back the seconds it costs. The other is a rule borrowed from one part of the method and used in another.

What a fill miss costs

A failed pull has four ordinary remedies and the exam knows all of them. Move to the next trade size, which raises the permitted side. Use a conductor type with a smaller area where the location suits it, which lowers the conductor side. Split the conductors between two raceways, which lowers the fill and the current-carrying count in each. Or rework the route so a short piece between enclosures earns the nipple allowance. Support spacing sits outside the area comparison, and one item offers it as a remedy to see who takes it.

Getting this wrong on site shows up as rework. An undersized raceway is usually found with the conductors already in it, so they come back out, a larger raceway goes in and the pull is made again. On a buried run the same discovery costs a trench as well. Underground runs and cover carries the burial side, and support and securing carries the requirement fill never touches.

The inspector you meet works from the edition and the amendments your city enforces. Texas cities keep the power to adopt local amendments to the National Electrical Code and to administer and enforce it, under Tex. Occ. Code 1305.201(c) and (d). Ask which edition and which amendments apply before you price work somewhere unfamiliar, and what a city can still require of you sets out where that power stops.

What to do before test day

The Texas exam is open book and you carry your own copy in, so the useful work is preparing the book. Four things pay for themselves:

• Tab the notes under Chapter 9, Table 1. They decide more answers than the table itself does, and they sit where nobody looks first.
• Find the 60 percent column in Chapter 9, Table 4 and mark it. Under a clock, people work out 60 percent of a total area by hand while the figure sits one column over.
• Practice Table 5 in the order it is built, insulation type first and then size. Two types at one wire size differ by enough to move a trade size on a full pull.
• Write the three-row test on your inside cover in your own words, with the multiconductor cable line underneath it.

One date belongs on your calendar. Texas adopts the 2026 National Electrical Code on 1 September 2026 under 16 TAC 73.100, so anyone testing after that date carries the 2026 book in, and which code edition applies to you covers what else moves with the adoption. The Chapter 9 fill method held its numbering through that change. The thirty free timed questions at practice will tell you inside a few minutes whether the three rows are genuinely in your hands, and box fill is the counting problem sitting beside this one on the same paper.

Questions people ask

How many conduit fill questions are on the Texas journeyman exam?

The published PSI content outline puts wiring methods and materials at 10 of the 56 scored items on the NEC knowledge portion and 2 of the 24 scored items on the calculations portion. Fill shares those slots with boxes, cable types and raceway installation rules, so a realistic expectation is a small handful spread across the two halves. Our own 500-item bank is weighted the same way: 51 items sit in the conduit and raceways area and 27 of those work the fill comparison. The topic earns its study time because it becomes fast once the sequence is drilled.

Does the 0.8 rounding rule apply to every pull?

It applies where every conductor in the raceway is the same size, meaning the same total area with the insulation counted. A division that lands on 8.83 then gives nine conductors. Mix two wire sizes, or run one wire size in two insulation types, and the note is closed and the count truncates to eight. The same uniformity test governs Annex C, which was built by applying that note, so both shortcuts open and close together. Exam items mix sizes on purpose to shut the door, and a candidate applying the note everywhere has swapped one wrong answer for another.

When does the nipple allowance apply?

Two conditions hold at once. The piece has to be 24 inches or shorter, and it has to run between boxes, cabinets or similar enclosures. Meet both and the conductors get 60 percent of the total internal area, and the conductor count adjustment factors are switched off as well. An 18 inch piece running from an enclosure into the rest of a raceway system meets the length and fails the location, so it carries the ordinary allowance. The relief exists because a short piece between two enclosures builds no heat and is barely a pull at all.

Do grounding conductors count in conduit fill?

Yes, at their own actual dimensions, insulated or bare. Everything inside the raceway occupies area whatever it carries, and a bare conductor is taken from the conductor properties table in Chapter 9. The point worth holding is that the same conductor stays outside the count used for the ampacity adjustment factors, since it carries no current in normal operation. One bank item runs both counts at once: adding a bare grounding conductor of 0.0134 square inches pushes the fill past the permitted area while the adjustment count holds at twelve, so one calculation fails and the other stands.

Which fill row does a multiconductor cable sit in?

A multiconductor cable counts as one conductor, taken on its own overall dimensions, and on the major diameter where the section is elliptical. One cable in a raceway puts you in the single-conductor row, which is the most generous of the three. Two cables put you in the two-conductor row, which is the tightest. Counting the conductors inside the jacket lands you in the over-two row and can move the answer by trade sizes. An item naming a cable type where you expected a wire type is asking this and nothing else.

Does the length of the run change the fill calculation?

Fill is an area comparison between the conductors and the raceway, and its only inputs are those two areas and the conductor count. The same pull in the same raceway gives the same result at 40 feet and at 140 feet. What length does bring is more supports, a bend count to watch over a longer route, and enough pulling tension to want a pull point partway along. The single place length enters the method at all is the nipple allowance, which is open at 24 inches or less between enclosures and closed above that.