Electrical Plan Symbols
Simple, original drawings of symbols commonly seen on electrical plans in the U.S. They are not copied from any published symbol sheet. Project drawings always control — many offices use IEEE / NFPA 170 / office-standard variants. Use the legend on the sheet in front of you.
Duplex receptacle
Two vertical slots and a U-ground, plan view. Add WP / GFCI / TR notes beside the symbol as needed.
GFCI receptacle
Same device body with a GFI / GFCI note. Used for bathrooms, kitchens, outdoor, garage, and other 210.8 locations.
Single-pole switch
S in a circle. Mounting height and load description go in the notes, not in the glyph.
3-way switch
S3. Traveler routing is shown in the switching diagram, not by this symbol alone.
4-way switch
S4, used between 3-way switches in a multi-location circuit.
Ceiling luminaire
Circle with a star / rays. A small tick or “W” may mark a wall-mounted light; stay consistent on the sheet.
Junction / outlet (generic)
Circle with a cross often marks a junction or a lighting outlet in older sheets. Confirm the legend on that drawing.
Panelboard / load center
Rectangle with circuit rows. Label as LP, MDP, or the panel name in the schedule.
Disconnect / safety switch
Enclosure with a schematic blade. Note fused vs non-fused and the ampere rating.
Motor
M in a circle. Add HP, voltage, and one-line wire size in the schedule.
Transformer
Two windings. Note kVA, voltages, and whether it is a SDS on the one-line.
Ground / grounding electrode
Standard stacked-bar ground symbol. Identify the electrode type (rod, Ufer, water pipe, ring) in the note.
Smoke detector / alarm
Letters in a circle. Follow the fire-alarm or residential-smoke legend on the drawing.
Fan (ceiling)
Circle over a stacked base; many sheets use “F” or a blade glyph instead. Match the project legend.
Thermostat
A boxed T is common on HVAC plans. Note low-voltage vs line-voltage.
These glyphs are for field recognition and training. Do not treat them as a substitute for a project’s official symbol legend or for a copyrighted standards plate (IEEE, NFPA 170, ISO, or a publisher’s drafting set).
Reference only — not engineering, legal, or code-compliance advice. Results are estimates for qualified persons and must be verified against the NEC edition adopted where the work is done (your selected edition), manufacturer instructions, and the local AHJ. Use is subject to the Terms of Use & Disclaimer. — Morningstar Electric LLC