Texas Electrician ExamTexas journeyman & master

Checked against primary sources 2026-08-24

Minimum cover is at 300.7 now, and cover still means the top of the pipe

The grid has a column for your wiring method or your circuit and a row for what sits over the run. You read one cell. Then you check whether the question asked for cover or for the depth of the hole, because they are different numbers.

On this page
  1. Where it lives, before anything else
  2. The columns are mostly methods, and two of them are not
  3. The rows describe what sits over the run
  4. Trench depth and cover are two different numbers
  5. One trench, two answers
  6. Where a run comes out of the ground
  7. Under a building is two rules at once
  8. Earth movement is a separate section from cover
  9. The short paragraphs around the table
  10. Voltage decides which article you are in
  11. The order of operations
  12. What this page cites

Where it lives, before anything else

Minimum cover for underground work at 1000 volts and below is a table inside NEC 300.7(A) in the 2026 book. In the 2023 book the same material is Table 300.5(A). Article 300 sits two sections lower this cycle, so a tab set for the older edition lands you two sections short, in the same article, on real code text about something else.

That address is worth more than any other fact on this page right now, because most of what is published about burial depth still points at 300.5 and will keep pointing there for a while.

A burial item hands you a wiring method, a place, and sometimes a circuit description. It wants one number. Everything else in the wording is scenery.

The columns are mostly methods, and two of them are not

They run from the least protected thing you can put in the ground to the most protected. A cable or conductor buried on its own sits at one end. Rigid metal conduit and intermediate metal conduit sit at the other. Nonmetallic raceway listed for direct burial without concrete encasement sits between them.

Hold the logic rather than the cells. Mechanical protection around the conductor buys a shallower trench, because the depth is standing in for protection. That gives you a sanity check that needs no memory at all: more protection never costs you a deeper hole, so an answer that puts metal conduit deeper than bare direct burial cable is wrong before you look anything up.

The last two columns are not wiring methods. They are circuit descriptions, and a circuit that fits one of them is read in that column whatever the pipe is made of. One covers a residential branch circuit at a limited voltage with ground-fault protection and a small overcurrent device. The other covers irrigation control and landscape lighting circuits at low voltage in identified cable or raceway. Both have qualifying figures attached, and you check them in the book rather than from memory.

Those two columns are where items are set. A candidate who reads past the circuit description lands in the general column and answers deeper than the code asks, which is a wrong answer that feels safe.

The rows describe what sits over the run

There is a base row for locations the table does not otherwise name, and then rows that pick out particular things overhead. A run under a building. A run under streets, highways, roads, alleys, driveways and parking lots. A run in or under airport runways and the adjacent areas closed to trespassers. Rows for concrete over the run, in a trench and as an exterior slab. And a row limited to one and two family dwelling driveways and outdoor parking used only for dwelling purposes.

Do not read those as a severity ladder. They are not ranked, and two of them reduce cover because of what is over the pipe rather than increase it because of traffic. Reading them as a ranking is how a candidate talks themselves out of the correct row.

Match on the words in the row instead. The dwelling row says one and two family, so an apartment complex parking lot is not in it and belongs with streets and parking lots. The airport row reaches runways and the closed areas beside them, so a general aviation apron open to tenants is a different question from a taxiway. The scenario names the place in trade language and the table names it in code language, and the translation is the work.

The table also has notes printed beneath it. Note 1 is the one that defines cover. Read the others once, with your own book open, because a note can change an answer the grid appears to have settled.

Trench depth and cover are two different numbers

Cover is the shortest distance from a point on the top surface of the buried conductor, cable, conduit or raceway to the top surface of finished grade, concrete or similar cover. The buried thing is the raceway itself and never the conductor inside it.

Obvious written down, and not obvious at seven in the morning in a trench. Dig to the number in the table, lay conduit on the bottom, and the top of that conduit sits shallower than the code asked by the whole outside diameter of the pipe.

The number you subtract is the outside diameter, not the trade size. On rigid conduit the outside diameter is larger than the trade size, so a candidate who subtracts the trade size gets an answer that is close, plausible, and short. If an item gives you a trade size and expects arithmetic, it expects you to know the difference.

The other half of the trap is the top end of the measurement. Cover runs to finished grade, concrete or similar cover, not to the dirt as it stood when the trench was dug. Grade cut down later takes the cover with it, which is why a landscaping plan can turn a compliant run into a violation without anybody touching the wire.

One trench, two answers

Say the table gives, for your method and your location, a cover of twenty inches. That figure is invented for this example and is not a value out of the book.

The trench is dug to twenty inches. The run is a conduit whose outside diameter is three and a half inches, laid on the bottom of the trench.

Cover is measured to the top of that conduit, so the cover is sixteen and a half inches and the installation is short by three and a half. Two fixes exist. Dig deeper, or move to a column that permits less cover. The second is a code answer rather than a shovel answer, and items are frequently built to reward it.

Now change one word in the scenario. Make it a residential branch circuit with ground-fault protection and a small overcurrent device. Same trench, same conduit, different column, and the installation may well pass on a number you never looked up the first time.

Where a run comes out of the ground

Direct-buried conductors and cables emerging from grade shall be protected by enclosures or raceways running from the cover depth below grade up to a point at least 8 feet above finished grade, and that protection is not required to extend more than 18 inches below finished grade (NEC 300.7(D)(1)).

Read it as one continuous run of protection with a defined top and a capped bottom. Protection that starts at grade level leaves bare the ankle-height stretch that mowers and vehicle doors actually hit, and protection that stops at head height leaves the rest of the riser.

Items on this are written as a described installation with the protection starting or stopping in the wrong place. Check both ends before you decide.

Direct-buried service conductors and underground service raceways that are not encased in concrete and that sit at or below a stated depth shall have their location identified by a warning ribbon placed in the trench above them (NEC 300.7(D)(3)). The 2026 edition added the raceways. The ribbon is not protection, it is a message to the next person with a backhoe.

Under a building is two rules at once

Cables installed under a building shall be installed in a raceway that is extended beyond the outside walls of the building (NEC 300.7(C)). The article carries an exception and it is worth reading in your own book, because it is the kind of narrow permission an item is built on.

That is separate from the cover figure. The table has its own row for a run under a building, and the two work together: the raceway requirement decides whether the cable may be there at all, and the row decides how much cover the run needs.

An answer that quotes the cover row and ignores the raceway is half an answer, and half answers are what the incorrect options are made of.

Earth movement is a separate section from cover

Where direct-buried conductors, raceways or cables are subject to movement by settlement or frost, they shall be arranged to prevent damage to the enclosed conductors and to equipment connected to the raceways (NEC 300.7(J)).

The section does not prescribe a fitting. It states an outcome and leaves the means open, and its informational note recognizes S loops at the transition from direct burial into raceway, expansion fittings in risers running to fixed equipment, and flexible connections into equipment that will settle.

This is not the thermal expansion rule and it is not the cover rule. Nothing in it depends on temperature swing and nothing in it depends on depth. The trigger is the ground moving, and in most of Texas that means settlement and expansive soil rather than frost.

The short paragraphs around the table

The table is one item on the paper. The paragraphs around it are the rest, and each of them is short enough to be an item on its own.

Voltage decides which article you are in

Everything above is the general case at 1000 volts and below. Systems above 1000 volts are handled in Article 305, which carries its own wiring method rules and its own underground section at 305.15, so a medium-voltage scenario is a different lookup rather than a harder version of the same one.

There is a way to confirm both numbers from inside the book, without turning to the front. Grounding electrode conductors and grounding electrode bonding jumpers in contact with the earth are not required to comply with 300.7 or 305.15, but are buried or otherwise protected where subject to physical damage (NEC 250.64(B)(4)).

A pair of sections that a grounding conductor gets specifically excused from, on the grounds that it is lying in dirt, is the pair that governs burial. The cross-reference is printed in the 2026 book, so it is a current address whether or not your memory is.

The order of operations

  1. Read the circuit description first. It can put you in a column of its own, and it is the input people skip.
  2. Name the wiring method and find its column if the circuit did not already decide one.
  3. Name what the run passes under, matching the words in the row rather than how bad the location sounds, and find the row.
  4. Read the one cell where they meet, then read the notes under the table.
  5. Decide whether the question asked for cover or for trench depth, and subtract the outside diameter of the raceway if it is the second.

Ten of the fifty-six scored items on the journeyman knowledge portion come from wiring methods and materials, and this section supplies more of them than its length suggests.

What this page cites

NEC and National Electrical Code are registered trademarks of the National Fire Protection Association.

Trojan Digital Marketing is an independent company. We are not affiliated with, endorsed by, or sponsored by NFPA, TDLR, PSI Services, or any licensing authority.

Bring your own current copy of the National Electrical Code. The Texas exam is open book.

All practice questions are original. They are not actual exam questions.

Built and maintained by Jeff Clerisier, Trojan Digital Marketing.

Every rule here is cited to the section it comes from, and corrections are logged in public with the date. This is study material rather than electrical advice, and it does not replace your own code book or your inspector.