Texas Electrician ExamTexas journeyman & master

Checked against primary sources 2026-08-24

The space in front and the space above are two different rules

Most candidates can quote one depth figure and miss everything else in the section. The marks sit in the conditions, in the entrance rules, and in the zone above the equipment that is not working space at all.

On this page
  1. What the section asks for before it asks for a number
  2. Where depth is measured from, and why the number moves
  3. The two dimensions nobody looks up
  4. Getting in and out, and the two ratings that change the answer
  5. The zone above the equipment is not working space
  6. Illumination, and the detail inside it
  7. Answering one of these under a clock
  8. What this page cites

What the section asks for before it asks for a number

Working space, and the access to and egress from it, has to be provided and maintained about all electrical equipment so the equipment can be operated and maintained safely (NEC 110.26).

The dimensions in 110.26(A) attach to equipment likely to require examination, adjustment, servicing or maintenance while energized. That qualifier does real work. A stem that describes the equipment carefully is often telling you whether the dimensions apply at all before it asks you for one.

Depth, width and height are three separate requirements and an installation satisfies all three or it fails. Generous width does not buy back short depth.

The working space in front of electrical equipment is a three dimensional box, not a floor marking A panel is mounted on a wall. In front of it a rectangular volume is marked out and you stand inside it. Depth is measured from the live parts where the live parts are exposed, and from the enclosure front or the opening where the live parts are enclosed, running out to the surface behind you. The panel drawn here is a dead-front assembly, so its datum is the front of the can and not the bus inside it, and reading it the other way loses you the whole depth of the enclosure. How much depth the code asks for depends on the voltage and on what the surface behind you is. Width is the greater of thirty inches or the width of the equipment, measured across the equipment. Height runs from the floor to six and a half feet or the top of the equipment, whichever is higher. The whole volume stays clear, and it is not storage. panel KEEP CLEAR not storage, floor to 6½ ft you, facing the panel height floor enclosure front, the datum here depth measured from the live parts if they are exposed, from the enclosure front or opening if enclosed WIDTH 30 in, or the equipment if it is wider. measured across the face, so it does not appear on a side view like this. HEIGHT 6½ ft from the floor, or the top of the equipment if that is higher. DEPTH, and what decides it the surface behind you. concrete is a grounded surface, a stud wall is not, and the worst case needs more room. all three apply at once. failing any one is a violation.
Depth, width and height are three separate rules. Most people only remember the depth one. Drawn against NEC 110.26(A)(1) through (A)(3). The datum moves with the equipment, and the panel drawn here is the enclosed case. Look the depth up in your book.

Where depth is measured from, and why the number moves

Distances are measured from the live parts where the live parts are exposed, and from the enclosure front or the opening where the live parts are enclosed (NEC 110.26(A)(1)). On a dead-front panelboard that means the front of the can, not the bus behind it, and getting it backwards costs you the depth of the enclosure.

The figure itself lives in Table 110.26(A)(1), indexed by nominal voltage to ground one way and by one of three conditions the other. Look it up. There is more than one number in it, which is the whole reason candidates who answer from memory lose these items.

The conditions are decided by what sits on the other side of the space, and they are prose, not arithmetic.

Read the guarding clause in Condition 1 twice, because live parts on both sides is not automatically Condition 3. Effective guarding by insulating material puts the same physical arrangement back into Condition 1, and an item that mentions an insulating barrier is testing precisely that.

There is also a permission most people have never read. Where equipment in an existing building is being replaced, Condition 2 clearance is allowed between dead-front assemblies sitting across an aisle from each other, provided written procedures stop both sides being opened at the same time and the people servicing it are qualified and authorized (NEC 110.26(A)(1)(c)).

And the section does not ask for working space behind or beside a dead-front assembly where every connection and every renewable or adjustable part can be reached from somewhere else. Where rear access is needed to get at nonelectrical parts, 30 inches of horizontal space is what it asks for instead (NEC 110.26(A)(1)(a)).

The two dimensions nobody looks up

Width is the width of the equipment or 30 inches, whichever is greater, measured across the face rather than in front of the one breaker in the stem (NEC 110.26(A)(2)). Equipment doors and hinged panels have to swing at least 90 degrees.

Height is clear space from the grade, floor or platform up to 6½ feet or the height of the equipment, whichever is greater (NEC 110.26(A)(3)). A duct run at 6 feet across the front of a panel is a violation of a dimension almost nobody checks.

The working space may not be used for storage (NEC 110.26(B)).

That last one is what catches a finished building. A clear space in a bare mechanical room does not stay clear once somebody needs a home for a ladder, and an item describing what else is in the room is usually planting exactly that.

Two more subsections are worth knowing exist. 110.26(A)(4) sets separate terms for equipment installed where access is limited, such as above a suspended ceiling. 110.26(A)(5) deals with equipment at 1000 volts ac or 1500 volts dc and below sharing a vault, room or enclosure with exposed parts operating above those voltages, which have to be separated off by a partition, fence or screen.

Getting in and out, and the two ratings that change the answer

Two amperage thresholds live in 110.26(C) and they do completely different jobs. Items on this subject routinely hand you the wrong one and see whether you notice.

Large equipment gets an entrance to and egress from the working space at each end, not less than 24 inches wide and 6½ feet high (NEC 110.26(C)(2)). Large equipment there is defined two ways: equipment rated 1200 amperes or more that is also over 6 feet wide, or a set of service disconnecting means, or building or structure feeder disconnects, whose combined rating reaches 1200 amperes and whose combined width is over 6 feet.

That second limb is the trap, because no single enclosure in the lineup has to be 1200 amperes. Six 400 ampere service disconnects standing side by side are added together, for rating and for width, and the group can land inside the rule while every piece of it looks small.

Note the conjunction on the first limb as well. Both halves have to be true. A 1200 ampere motor control center that is 5 feet wide is not large equipment for this purpose.

Two exceptions bring it back to one entrance, one turning on unobstructed egress and one on doubling the working space depth. Read them in your own book rather than trying to remember which is which.

The door rule is a different number and a different subject. Where equipment rated 800 amperes or more that contains overcurrent, switching or control devices is installed, and a personnel door intended for entrance to or egress from that working space sits less than 25 feet from the nearest edge of it, the door has to open at least 90 degrees in the direction of egress and carry listed panic hardware or listed fire exit hardware (NEC 110.26(C)(3)).

So 1200 amperes governs how many ways out there are, and 800 amperes governs how the door behaves. Neither number tells you anything about the other.

The zone above the equipment is not working space

110.26(E) reserves a different volume for a different reason, and confusing the two is the most productive mistake on this subject. The dedicated space is the footprint of the equipment, its own width and its own depth, running from the floor to 6 feet above the equipment or to the structural ceiling, whichever is lower.

Working space is in front of the equipment and exists so a person can stand there. Dedicated space is the column the equipment sits in and exists so somebody else’s pipe does not end up over your gear. Piping, ducts, leak protection apparatus and other equipment foreign to the electrical installation may not occupy that zone (NEC 110.26(E)).

Above the dedicated space the answer flips. Foreign systems are allowed up there where protection is installed against condensation, leaks and breaks. Sprinkler protection for the room is allowed. A suspended ceiling with removable panels is allowed inside the dedicated space itself, which is the clue that a dropped ceiling is not the structural ceiling the 6 feet is measured to.

Illumination, and the detail inside it

Working spaces about service equipment, switchboards, switchgear, panelboards and motor control centers installed indoors have to be lit, and the catch is that control of all the luminaires by automatic means is not permitted within the working space (NEC 110.26(D)).

An occupancy sensor as the only control fails. A wall switch you can reach passes. No dimension is attached to this one at all, which is exactly why it gets asked.

One more short subsection: an electrical equipment room or enclosure kept locked is still considered accessible to qualified persons (NEC 110.26(F)). A stem that mentions a locked electrical room is usually not describing a violation.

Answering one of these under a clock

  1. Decide whether the dimensions apply. They attach to equipment likely to be examined, adjusted, serviced or maintained while energized.
  2. Name which of the six answers the stem wants. Depth, width, height, entrance, illumination and the dedicated space are separate rules with separate numbers.
  3. For depth, settle the condition before you open the table. The condition comes from what is on the other side of the space, and the table is entered by condition and by voltage together.
  4. Check the stem for a second violation before you commit. These items are usually written with one loud problem and one quiet one, and the quiet one is often above the equipment rather than in front of it.

Put one tab where Table 110.26(A)(1) starts and a second on 110.26(E). The second tab earns more, because the dedicated space is the rule people go looking for and cannot find, and by the time they find it they have spent four minutes.

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.