Electrical plans for US electricians: symbols, circuits and home runs
What a US residential electrical plan shows and how it is drawn: receptacles with GFCI and AFCI where the code calls for them, single-pole, 3-way and 4-way switches, lighting outlets, the panel, circuits and home runs, in feet and inches at 120/240 V.
A US residential electrical plan shows every receptacle, switch, lighting outlet and fixed appliance on the floor plan in ANSI/NECA-style symbols, with GFCI and AFCI protection noted where the code calls for it, each device's circuit numbered to the panel, a home run for each circuit, and dimensions in feet and inches. Your local code and inspector decide the details.
This page is the US version of the residential plan article, in the words and marks a US plan uses. If your work crosses the Atlantic, the IEC vs US article puts the two conventions side by side.
What goes on a US residential electrical plan?
Under everything is the floor plan, drawn to scale, often at 1/4 inch to the foot for a house, with each room named. On it sit the devices, the switching, the circuits and the notes, with a legend and a title block around them.
| Layer | What it shows | How it is usually drawn |
|---|---|---|
| Receptacles | Every place a cord plugs in, with GFCI, weatherproof and 240-volt ones marked | A circle with lines through it, letters beside it |
| Switches | Every switch, with 3-way and 4-way switches marked | The letter S, with a 3 or a 4 |
| Lighting outlets | Ceiling and wall fixtures, recessed lights, fans | A circle and its variants |
| Switching | Which switch controls which light | A curved line, often dashed, from switch to light |
| Fixed equipment | Range, dryer, water heater, air conditioning, EV charger | A mark of its own, on a dedicated circuit |
| Smoke and CO alarms | Where the alarms go | A lettered mark on the ceiling |
| The panel | Where every circuit starts | A rectangle, often hatched, with the panel's name |
| Circuits and home runs | The circuit feeding each device, and the run back to the panel | Circuit numbers, and an arrow toward the panel |
| Notes and legend | GFCI and AFCI requirements, mounting heights, the symbols used | Text on the sheet |
Which symbols do US plans use?
Most US plans use marks that descend from the old ANSI Y32.9 table and NECA's later guidance, with each firm's own variations. That is why the legend matters: on any sheet, a mark means what the legend says it means. These are the marks ePlan draws when a device is set to US symbols.
| Symbol | Name | Where it goes |
|---|---|---|
| Duplex receptacle | Walls of every room, at the spacing the code sets | |
| GFCI receptacle | Bathrooms, kitchen counters, garages, outdoors and other wet or damp places | |
| Weatherproof receptacle, WP | Outdoors, under a weatherproof cover | |
| 240-volt receptacle | A dryer, a range or a large tool, on a circuit of its own | |
| Split-wired receptacle | Half switched, for a lamp in a living room or bedroom | |
| Quad receptacle | Two duplexes in one box, behind a desk or a TV | |
| Ceiling receptacle | A garage door opener | |
| Single-pole switch, S | A light switched from one place | |
| 3-way switch, S3 | One of a pair switching a light from two places | |
| 4-way switch, S4 | Between a 3-way pair, for a third place | |
| Occupancy sensor switch | Closets, laundry rooms, garages | |
| Ceiling lighting outlet | A fixture on the ceiling | |
| Recessed light | A can or wafer light in the ceiling | |
| Wall lighting outlet | A sconce or a bracket light | |
| Ceiling fan | On a box rated for a fan | |
| Smoke/CO alarm | Bedrooms, the hall outside them and every level, as your code requires | |
| Panel | The panelboard, where every circuit starts | |
| Range outlet | The range, on a 240-volt circuit |
The symbols chart has every device in both conventions.
How are 3-way and 4-way switches drawn?
A light switched from one place gets an S beside the door. Switched from two places, at the top and bottom of a stair or at two doors of a long room, it gets a pair of S3 marks: 3-way switches, joined by two travelers. A third place adds an S4, a 4-way switch, between the pair, and more 4-ways can follow.
The plan does not draw the travelers. It draws a line from each switch to the next and to the light, so the reader sees which switches work together. US plans often draw these lines dashed; ePlan draws them as solid curves, colored by circuit.
The two-way switch article has a simulator to flick. Europe calls the 3-way switch a two-way switch, and the wiring is the same.
Where do GFCI and AFCI protection go?
GFCI protection is marked at the receptacle, with GFCI (or GFI) beside the duplex mark. The usual places are bathrooms, kitchens, garages, outdoors, basements, crawl spaces, laundry areas and anywhere near a sink. The list has grown with each edition of the NEC, so the edition your jurisdiction adopted decides it.
AFCI protection is usually a note, not a mark. Recent editions require it on most 120-volt, 15- and 20-amp circuits that feed a home's living spaces, and it is usually provided by a breaker in the panel, so plans say it once, in the notes or on the panel schedule.
ePlan has a GFCI receptacle mark and, like most plans, no AFCI mark. Put the note where the reader will see it: in a receptacle's label, or in the circuit's name, C3 AFCI for example, which the PDF's legend lists.
How are circuits and home runs shown?
Each device carries the number of the circuit that feeds it, matching a breaker in the panel: odd numbers down one side, even down the other, a 240-volt circuit taking two spaces. Devices on one circuit are joined by lines. The home run, the cable from the panel to the first box on the circuit, is drawn as an arrow pointing toward the panel and labeled with the panel's name and the circuit number.
| Circuit | Usual size | What it feeds |
|---|---|---|
| General lighting and receptacles | 15 or 20 A, 120 V | Bedrooms, living areas, halls |
| Small-appliance circuits | 20 A, 120 V, at least two | Kitchen counter and dining receptacles |
| Laundry | 20 A, 120 V | The washer's receptacle |
| Bathroom receptacles | 20 A, 120 V | The bathroom receptacles |
| Range | 40 or 50 A, 240 V | The range, or a cooktop and an oven |
| Dryer | 30 A, 240 V | An electric dryer |
| Water heater, air conditioning, EV charger | As the nameplate requires, 240 V | Each on its own circuit |
These are common choices, not rules: the nameplate, the code edition and your inspector decide.
In ePlan, a circuit is a name. The wire tool numbers new circuits C1, C2 and on, and any name can be typed instead, so a plan can use the panel's own numbers. ePlan does not draw a home-run arrow: draw a wire from the first device on each circuit to the panel symbol. That wire is what Test mode's Check follows back to the panel.
Feet and inches, 120/240 volts and Letter paper
| On US plans | In ePlan | |
|---|---|---|
| Dimensions | Feet and inches, such as 12'-6" | Drawn walls and 3D room scans show feet and inches on a device set to US units |
| Scale | Often 1/4" = 1'-0" for a house | An imported PDF or photo keeps its own scale; ePlan does not measure on it |
| Voltage | 120 V for lighting and receptacles, 240 V for the big loads | The load estimate works at 120 V, with 240-volt equipment at 240 V |
| Breakers | 15 and 20 A, larger for the big loads | The Loads tab steps through 15, 20, 30, 40, 50 and 60 A |
| Paper | Letter and Tabloid, larger sheets for a full set | The PDF takes the plan's own shape or a US Letter page |
How does ePlan draw a US plan?
- Set US symbols. A device set to the US, Canada, Mexico or the Philippines starts with them. Anywhere else, tap the symbol size button in the editor and choose US under the slider, or use Symbols in the account menu. The choice belongs to the device, so a colleague in Europe can open the same plan in IEC symbols.
- Bring in the floor plan. Import the architect's PDF and pick its pages, photograph a paper plan, scan the rooms on an iPhone or iPad with LiDAR, or draw the walls on a grid, 2 feet a square on a device set to US units.
- Place the devices. Drag receptacles, switches and lights from the palette. The palette and the PDF's legend use the US drawings and names.
- Wire the circuits. Pick a circuit, tap a symbol, then the next. Draw each switch to its light and each circuit back to the panel.
- Test it. Check finds devices with no path from a panel, Simulate flips the 3-way and 4-way switches, and Loads gives an indicative load per circuit. Test mode is part of Premium.
- Export. A PDF at the plan's own shape or on US Letter, with a legend in US names, or a picture of the same page.
What is the load estimate, and what is it not?
With US symbols, ePlan's Loads tab adds a typical load for each device on a circuit, divides each by its own voltage, and compares the current with the breaker you choose. It is a quick screen for a circuit that is plainly overloaded on paper.
| Device | Assumed load |
|---|---|
| Receptacle, single, duplex or GFCI | 180 VA at 120 V |
| Ceiling light | 100 VA at 120 V |
| Recessed light | 50 VA at 120 V |
| Dishwasher | 1,200 VA at 120 V |
| Washer | 1,500 VA at 120 V |
| Range outlet | 8,000 VA at 240 V |
| Dryer | 5,000 VA at 240 V |
| Water heater | 4,500 VA at 240 V |
| EV charger | 7,700 VA at 240 V |
It is not an NEC calculation. A home's service and feeders are sized under Article 220, with an allowance per square foot for general lighting and receptacles, set allowances for the small-appliance and laundry circuits, and demand factors, and a permit's calculation follows the edition your jurisdiction adopted. The Loads tab says under its figures that they are indicative. The load calculation article goes further.
Common mistakes on US plans
- 3-way switches drawn as plain S marks. A plain S is a single-pole switch, and two of them cannot share a light. Mark the pair S3 and draw them to each other and to the light.
- The kitchen counter on one circuit. Codes generally want at least two 20-amp small-appliance circuits there. Check your edition.
- A circuit with no home run. Without the run to the panel, nobody can tell which breaker feeds it, and Check cannot either.
- GFCI left to memory. Mark it where it is required, or say in a note how it is provided.
- A 240-volt appliance with no circuit of its own. The range, dryer, water heater and air conditioning each need one on the plan.
- Metric dimensions or IEC marks on a US plan. A US reader expects 12'-6" and S3, not 3.8 m and a circle with two strokes.
- The load estimate offered as the service calculation. It is a screen, not Article 220.
Questions
Is an outlet the same as a receptacle?
In everyday speech, yes. In the NEC, an outlet is any point where current is taken to supply equipment, a lighting outlet included, and a receptacle is the device a plug goes into. Plans use both words, and the legend says which mark is which.
What does S3 mean on an electrical plan?
A 3-way switch, one of a pair that controls a light from two places. S4 is a 4-way switch between such a pair, and a plain S is a single-pole switch.
Do I have to show AFCI protection on the plan?
Usually as a note rather than a mark: which circuits are protected, and how. What a plan must show is up to your jurisdiction's code edition and your inspector.
Can I draw a US plan in ePlan on a phone set to another region?
Yes. Choose US under the symbol size slider, or in Symbols in the account menu. The plan itself does not change, only how this device draws and names it.
Does ePlan's load estimate count for a permit?
No. It is an indicative figure per circuit at 120 and 240 volts. A permit's load calculation follows Article 220 of the NEC edition your jurisdiction adopted, and the inspector checks it.
What paper size should I export?
US Letter prints anywhere. For a larger sheet, export at the plan's own shape and let the printer scale it to Tabloid.