7.1 Receptacles, Switches, and Device Selection

Device selection as a code workflow

Journeyman exams treat wiring devices as more than trim. A receptacle, snap switch, dimmer, occupancy sensor, cord connector, attachment plug, or controller is part of the electrical installation and must be suitable for the circuit, environment, load, and manner of use. The common mistake is to choose a device because it physically fits the box. The exam asks whether it is permitted, rated, listed, grounded, protected, and installed in the required location.

Use this device-selection sequence before you answer:

On R17, T17, and G17 exams, the exact scope of some GFCI, AFCI, and dwelling device rules can vary by NEC edition. R17 uses the 2023 NEC, T17 uses the 2020 NEC, and G17 uses the 2017 NEC. Do not answer from a 2026 habit or from a local amendment unless the question tells you to. The ICC national journeyman exam is open book, but 80 questions in 4 hours means you need to know where these rules live.

Receptacle rating logic

A receptacle question often turns on whether the receptacle is single, duplex, part of a multioutlet branch circuit, or installed for one specific appliance. A 15 A duplex receptacle on a 20 A general-purpose branch circuit may be allowed in a common multioutlet setup, while a single receptacle on an individual branch circuit must be checked more strictly against the branch-circuit rating. Read the stem closely. The phrase "single receptacle" is not the same as "duplex receptacle."

Match receptacle configuration to voltage and ampere rating. A 125 V, 15 A receptacle is not a universal answer for every 120 V load. Cord-and-plug connected equipment may have a required receptacle configuration based on the equipment nameplate, branch-circuit rating, and listing instructions. If a question gives a NEMA configuration, voltage, or amperage, treat it as a clue that device rating matters.

Location-driven device features

Several device features are location based. GFCI protection addresses shock risk. AFCI protection addresses arcing fault risk in specified dwelling areas. Tamper-resistant receptacles reduce child access to live contacts in required locations. Weather-resistant receptacles are built for outdoor or wet/damp exposure. Covers may need to protect the receptacle while a cord is inserted, not merely when the cover is closed.

Exam trap: a GFCI device is not automatically weather resistant, tamper resistant, or suitable for wet locations. Those are separate markings or installation requirements. Another trap is using a weatherproof cover that protects only when closed in a location where the receptacle must remain weatherproof with a cord plugged in.

Switches and controlled loads

Article 404 switch questions usually ask whether the switch is permitted for the load and whether it is installed in a compliant way. A general-use snap switch is not the same as a motor-circuit switch. A dimmer is not automatically suitable for every LED driver or fluorescent ballast. Electronic lighting controls may need a neutral conductor in the box, depending on the rule and device type in the tested edition.

Switching the grounded conductor is usually prohibited except in specific permitted arrangements. The exam may present a switch loop, a pilot-light switch, a smart switch, or a disconnecting means and ask what conductor must be present or what is not allowed. Keep the concepts separate: a wall switch controls a load, a disconnect isolates equipment, and an overcurrent device protects conductors and equipment within its rating.

Device boxes and yokes

Device selection does not stop at the strap. The box must have enough volume for conductors, device yokes, internal clamps, equipment grounding conductors, and splices. Receptacles and switches with larger bodies, dimmers, GFCI devices, and smart controls can create practical space problems even when the box-fill arithmetic is technically acceptable. For the exam, apply Article 314 box-fill rules when the question gives conductor sizes and counts.

Grounding and bonding also matter. Metal boxes, device yokes, and equipment grounding conductors must be connected so a fault can clear. Self-grounding devices have listing conditions; they are not a magic fix for every metal box or cover combination. If the stem mentions isolated grounding, hospital-grade devices, metal faceplates, or a nonmetallic box, slow down and identify the grounding path.

Installation cases

Case 1: A 20 A bathroom branch circuit supplies a single bathroom receptacle outlet and lighting in that same bathroom. Depending on the exact rule, this can be permitted only under limited conditions. The exam may test whether the bathroom receptacle circuit serves other bathrooms or other loads.

Case 2: An exterior dwelling receptacle is replaced with a GFCI receptacle, but the device is not weather resistant and the cover is not suitable for use with a cord inserted. The installation may still fail even though GFCI protection is present.

Case 3: A smart switch is installed in an old switch loop with no grounded conductor in the box. If the tested edition requires a grounded conductor at many switch locations and no exception applies, the correct answer is not to borrow a neutral from another circuit. Shared neutrals and random conductor borrowing create objectionable current paths and troubleshooting hazards.

Exam approach

Underline device words: single receptacle, duplex, individual branch circuit, GFCI, AFCI, tamper resistant, weather resistant, damp, wet, motor, dimmer, LED, switch loop, grounded conductor, metal box. Then choose the article. Receptacles usually point to Article 406 plus Article 210. Switches point to Article 404 plus the load article. Boxes point to Article 314. Grounding points to Article 250. Most wrong answers skip one of those layers.