🚧 Under construction — VoTechWorks is being built. A free tech program — complimentary, as our commitment to get America working.
voTechWorksGrade 13 · a vocational technology learning center, by urbanicity
newSchoolWorks.com › VoTechWorks › Building & Construction › Electrical › Externship / Worksite Placement › Lesson 2
BLD-ELEC05-09 · Lesson 2 · 180 clock hours · field

Supervised Field Work — Phase 1: Rough-In and Infrastructure

Objective. Students will assist journeyman electricians with conduit installation, wire pulling, box setting, panel rough-in, and grounding tasks, producing work that meets NEC requirements and passes site inspection.

Supervised Field Work — Phase 1: Rough-In and Infrastructure

The rough-in phase is when an electrical system takes its physical shape inside walls, ceilings, and mechanical spaces before any finish work covers it. During your Phase 1 externship you will work alongside a licensed journeyman electrician on real construction sites, performing the foundational tasks that every subsequent phase of electrical work depends on. This lesson prepares you to participate safely and productively.

What Happens During Rough-In

Rough-in work includes running conduit pathways, setting device and junction boxes, pulling conductors through installed conduit, and making initial connections at panels and boxes. The work must conform to the National Electrical Code (NEC) and any applicable local amendments. Your supervising journeyman is your primary authority on site; their direction and sign-off carry legal and quality weight.

Common rough-in tasks you will perform:

Safety First on the Worksite

Worksite hazards are real and consequential. Follow these requirements every day:

Personal Protective Equipment (PPE): Wear a hard hat, safety glasses, and steel-toed boots at all times in active construction zones. Cut-resistant gloves are required when handling conduit edges or pulling wire. When there is any chance of exposure to energized parts, use appropriately rated insulated gloves and tools, and don arc-flash PPE if required by the site's energized-work policy.

Lockout/Tagout (LOTO): No work may begin on any circuit, panel, or equipment until it is verified de-energized and properly locked and tagged out under the site's LOTO program. You are not authorized to restore energy to any circuit — that action belongs to the supervising journeyman or a designated qualified person. Treat every conductor as energized until a voltage tester confirms otherwise.

Housekeeping: Keep work areas clear of conduit offcuts, wire scraps, and tools. Tripping hazards cause a significant share of construction injuries. At the end of each shift, remove debris from your work zone.

Tool inspection: Before using any power tool, inspect the cord and housing for damage. Report defects to your journeyman immediately and tag the tool out of service.

Ladder and elevation safety: Use the correct ladder for the task, maintain three points of contact, and never overreach. Follow fall-protection requirements for elevated work platforms.

Conduit Installation Standards

Every conduit run must be secured within the distance required by the NEC and supported at intervals that prevent sagging. Bends must not reduce the internal diameter enough to damage insulation during wire pull. The total number of bends between pull points is limited by the NEC to avoid excessive pulling tension — know the site drawings before you start a run so you can plan pull points.

When making a 90-degree bend with a hand bender, confirm the take-up distance for the conduit size you are using, mark the conduit, seat it in the bender at the correct arrow, and apply steady foot pressure. Check the angle with a level or protractor. A poorly made bend creates stress on conductors and makes future wire replacement harder.

Wire Pulling Best Practices

Always use a listed wire-pulling lubricant — never petroleum-based products on thermoplastic insulation, as they can degrade the jacket. Calculate the number of conductors and their fill percentage relative to the conduit size before pulling; NEC conduit-fill tables apply. Pull conductors smoothly and steadily; sudden jerks can nick insulation at fittings. After pulling, label each conductor at both ends before the next crew covers the work.

The Daily Field Log

Your field log is a professional document and a program requirement. Every workday, record:

1. Date, site name, and supervising journeyman's name.

2. Specific tasks performed (e.g., "bent and installed 1-inch EMT run from panel to first junction box, approx. 40 ft").

3. NEC articles you observed applied or referenced.

4. Tools used.

5. Any safety incident or near-miss, no matter how minor.

Your journeyman initials each entry that day. An unsigned entry is an incomplete entry. Treat the log the way you treat a circuit: if it is not documented, it did not happen.

Quality and Inspection

All rough-in work is subject to inspection by the Authority Having Jurisdiction (AHJ) — typically the local building department. If an inspector rejects work, you must document the rejection in your log, correct the deficiency under journeyman supervision, and have the corrected work re-verified before the next inspection. The goal is to form habits that produce inspection-ready work the first time.

Key terms10

Rough-inThe phase of electrical construction in which conduit, boxes, and conductors are installed inside the building structure before walls and ceilings are closed, prior to any device or fixture installation.
EMT (Electrical Metallic Tubing)A lightweight, thin-wall metal conduit commonly used for branch circuits and feeders in commercial and residential construction; requires fittings approved for the application.
Equipment Grounding Conductor (EGC)A conductor that provides a low-impedance fault-current path between non-current-carrying metal parts of equipment and the grounding system, allowing overcurrent devices to operate during a fault.
Lockout/Tagout (LOTO)An OSHA-required safety procedure in which energy sources are isolated and physically locked in the de-energized position and tagged to prevent accidental re-energization while work is performed.
Authority Having Jurisdiction (AHJ)The organization, office, or individual responsible for enforcing the requirements of a code or standard, such as a local building department electrical inspector.
Conduit fillThe percentage of a conduit's interior cross-sectional area occupied by conductors; the NEC specifies maximum fill percentages depending on the number of conductors to protect insulation and allow heat dissipation.
Take-up (bend allowance)The length of conduit consumed by a bend, measured from the mark on the conduit to the end of the finished bend; varies by conduit size and must be accounted for when measuring stub length.
Wire-pulling lubricantA listed compound applied to conductors or fish tape to reduce friction during the wire-pulling process; must be compatible with the conductor insulation type.
Panel rough-inThe process of mounting the panel enclosure, securing feeder and branch-circuit conduits, landing conductors at the correct terminations, and establishing grounding and bonding connections before cover installation.
Field logA daily written record kept by the apprentice or student documenting tasks performed, code references observed, tools used, and any safety events; signed by the supervising journeyman each workday.

Worked examples4

1. You need to install a 90-degree stub-up of 3/4-inch EMT so the conduit rises exactly 12 inches above the concrete floor. The take-up for 3/4-inch EMT with a standard hand bender is 5 inches. Where do you place your bender mark on the conduit?
  1. Step 1 — Identify the desired stub length: 12 inches above the floor.
  2. Step 2 — Recall the take-up distance for 3/4-inch EMT: 5 inches. Take-up is the amount of conduit used by the bend itself.
  3. Step 3 — Subtract the take-up from the desired stub length: 12 in − 5 in = 7 inches.
  4. Step 4 — Measure 7 inches from the end of the conduit and place your mark there. Align the mark with the arrow on the hand bender, then bend to 90 degrees.
  5. Step 5 — After bending, verify the stub measures 12 inches from the floor reference point. Adjust technique if the stub is short or long for the next piece.
Answer: Place the bender mark 7 inches from the end of the conduit. After bending, the stub should measure 12 inches.
2. You are pulling three 12 AWG THHN conductors through 1/2-inch EMT. The NEC conduit-fill table shows the internal area of 1/2-inch EMT is 0.304 square inches. Each 12 AWG THHN conductor has a cross-sectional area of 0.0133 square inches. The NEC allows a maximum 40% fill for three or more conductors. Does this combination comply?
  1. Step 1 — Calculate the total conductor area: 3 conductors × 0.0133 sq in = 0.0399 sq in.
  2. Step 2 — Calculate the maximum allowable fill area: 0.304 sq in × 0.40 = 0.1216 sq in.
  3. Step 3 — Compare total conductor area to maximum fill: 0.0399 sq in < 0.1216 sq in.
  4. Step 4 — Since the total conductor area is less than the maximum allowable fill, the installation complies with NEC conduit-fill requirements.
Answer: The combination complies. The conductors occupy approximately 0.0399 sq in, well under the 0.1216 sq in maximum for 40% fill in 1/2-inch EMT.
3. You need to make a 3-point saddle bend in 3/4-inch EMT to clear a 2-inch obstruction (such as a water pipe). Using the standard multiplier for a 22.5-degree saddle, calculate the distance between the center bend mark and each outer bend mark.
  1. Step 1 — Identify the obstacle height: 2 inches.
  2. Step 2 — Recall the multiplier for a 22.5-degree saddle bend: 2.6 (a standard value used in the trade for the center-to-outer-mark spacing).
  3. Step 3 — Multiply the obstacle height by the multiplier: 2 in × 2.6 = 5.2 inches.
  4. Step 4 — Mark the center of the obstacle on the conduit. Measure 5.2 inches to each side of the center mark for the two outer bend marks.
  5. Step 5 — Bend the center mark to 45 degrees, then each outer mark to 22.5 degrees (rolling the conduit 180 degrees for the second outer bend) to complete the saddle.
Answer: Place the outer bend marks 5.2 inches on each side of the center mark to produce a saddle that clears a 2-inch obstacle.
4. A conduit run will have four 90-degree bends between two pull boxes. Before pulling wire, you want to confirm the NEC constraint on bends is not exceeded. How many total degrees of bends are in this run, and does it comply?
  1. Step 1 — Identify the number of bends and their angle: four 90-degree bends.
  2. Step 2 — Calculate total degrees: 4 × 90 degrees = 360 degrees.
  3. Step 3 — Recall the NEC rule: the total number of bends between pull points shall not exceed 360 degrees (equivalent to four quarter-turns).
  4. Step 4 — Compare: 360 degrees = 360 degrees. The run is exactly at the NEC maximum and therefore complies, but no additional bends may be added. Adding even a small offset would exceed the limit and require an additional pull point.
Answer: The run totals 360 degrees of bends, which equals — and does not exceed — the NEC maximum between pull points. No additional bends may be added.

The math in this lesson2

Learners place a 12 in stub mark using take-up, compute conduit fill, and space saddle marks with multipliers.
7.RP.3N-Q.1
Brush up in the math halls at newSchoolWorks.com:
In class: Install EMT and rigid conduit runs using offsets, saddle bends, and 90-degree bends learned in the conduit-bending course; have each run verified by the supervising journeyman before securing. · Pull wire through installed conduit, label conductors according to site drawings, and terminate at junction and device boxes under direct journeyman supervision. · Complete daily field-log entries each workday recording the specific tasks performed, NEC articles referenced or observed applied, tools used, and any safety incidents or near-misses.
Materials: Conduit benders (hand and mechanical), fish tape, wire-pulling lubricant, EMT and rigid conduit, wire and cable per site spec, voltage tester, digital multimeter, site drawings, NEC code book, field-log booklet
Check: Journeyman initials each daily log entry confirming task completion and acceptable quality; at least 90% of entries completed without omissions. Any work rejected by inspection must be documented, corrected, and re-verified. Pass = journeyman sign-off on every logged workday with no more than two corrective re-dos per 30-hour block.

Practice check8

Answer each question, then check it. Nothing is recorded; this is your own practice.

OSHA 10 — Electrical Safety
1. Before beginning any work on a circuit that may have been energized, what is the correct first action according to OSHA LOTO requirements?
NCCER Electrical — Conduit Installation
2. The NEC limits the total degrees of bends in a conduit run between pull points to:
NCCER Electrical — Wire and Cable Installation
3. Which of the following lubricants is acceptable to use when pulling THHN conductors through conduit?
NCCER Electrical — Professional Practice
4. A journeyman rejects a section of EMT you installed because the supports are spaced farther apart than the NEC requires. What must you do next according to program requirements?
NCCER Electrical — Boxes and Enclosures
5. When setting a device box in a framed wall, which measurement is most critical to check before securing the box?
NCCER Electrical — Grounding and Bonding
6. What is the primary purpose of the equipment grounding conductor (EGC) in a branch circuit?
NCCER Electrical — Wire and Cable Installation
7. You are labeling conductors after pulling them through conduit. According to professional practice, when should conductors be labeled?
State Journeyman Electrician — Hours and Documentation
8. The daily field log you maintain during your externship serves which of the following purposes?
Record this lesson on my transcript. Sign in with your key and enrollment email to record lessons (enroll free if you have no key). This page stays open to read and practise.
← Previous lessonProgram planNext lesson →