Electrical Symbols
Blueprint symbols for receptacles, switches, lighting, panels, wiring, and motor controls.
6 reference items · 6 sections
Receptacle Symbols
Receptacle Outlet Symbols
| Symbol | Meaning | Notes |
|---|---|---|
| Duplex receptacle (standard) | NEMA 5-15R or 5-20R | |
| Weatherproof receptacle | Outdoor, GFCI required | |
| GFCI receptacle | Required: bath, kitchen, garage, outdoor | |
| Special-purpose receptacle | Dedicated circuit | |
| 240V receptacle | Dryer, range, etc. | |
| Receptacle on specific circuit | Number = circuit ID | |
| Floor receptacle | Flush or poke-through | |
| Isolated ground receptacle | Orange face, dedicated ground | |
| Multi-outlet assembly | Continuous strip of outlets |
1.Symbols may vary between architects/engineers — always check the drawing legend
2.Height from floor shown as number near symbol (e.g., 48" for countertop)
Switch Symbols
Switch Symbols
| Symbol | Meaning | Notes |
|---|---|---|
| Single-pole switch | Controls from one location | |
| Double-pole switch | Switches both hot legs (240V) | |
| Three-way switch | Controls from two locations | |
| Four-way switch | Controls from 3+ locations (with two 3-ways) | |
| Dimmer switch | Variable light level | |
| Weatherproof switch | Outdoor rated | |
| Key-operated switch | Security application | |
| Switch with pilot light | Indicates when load is on | |
| Timer switch | Automatic off after time delay | |
| Motion/occupancy sensor | Auto on/off with occupancy |
1.Dashed line from switch to fixture shows switching relationship
2.Subscript number indicates switch type (3=3-way, 4=4-way)
Lighting Fixture Symbols
Lighting Symbols
| Symbol | Meaning | Notes |
|---|---|---|
| Ceiling-mounted light | Incandescent or LED | |
| Recessed can light | In ceiling | |
| Surface-mounted fixture | On wall or ceiling | |
| Fluorescent/LED strip | Surface or pendant mount | |
| Recessed fluorescent | 2×4 or 2×2 troffer | |
| Wall-mounted sconce | Usually decorative | |
| Exit sign | Emergency/egress lighting | |
| Emergency light | Battery backup | |
| Track lighting | Adjustable direction | |
| Outdoor pole light | Parking lot, pathway |
1.Letter/number next to symbol indicates fixture type per fixture schedule
2.Wattage often shown next to fixture symbol
Panel & Equipment Symbols
Panel & Equipment Symbols
| Symbol | Meaning | Notes |
|---|---|---|
| Panelboard | Labeled with panel name (A, B, etc.) | |
| Transformer | Step-up or step-down | |
| Motor control center | Multiple motor starters | |
| Automatic transfer switch | Generator/utility switching | |
| Generator | Backup power | |
| Electric meter | Utility metering point | |
| Main distribution panel | Service entrance panel | |
| Safety disconnect switch | Lockout/tagout point |
1.Panel schedules provide circuit details for each panelboard
2.One-line (single-line) diagrams show overall power distribution
Wiring & Raceway Symbols
Wiring Method Symbols
| Symbol | Meaning | Notes |
|---|---|---|
| Wiring in ceiling/above | — | |
| Wiring in floor/below | — | |
| Number of conductors (ticks = wires) | — | |
| Home run to panel (arrow to panel) | — | |
| Home run — identifies panel and circuit | — | |
| Wiring turned up (rises to above) | — | |
| Wiring turned down (drops below) | — | |
| Conduit run | — |
1.Tick marks across wire: each tick = one conductor beyond the default 2
2.Default assumption: 2 conductors unless marked otherwise
Motor & Control Symbols
Motor & Control Device Symbols
| Symbol | Meaning | Notes |
|---|---|---|
| Motor | — | |
| Generator | — | |
| Transformer | — | |
| Resistor / heater element | — | |
| Inductor / relay coil | — | |
| Capacitor | — | |
| Normally open contact | — | |
| Normally closed contact | — | |
| Overload relay | — | |
| Push button | — | |
| Limit switch | — | |
| Pressure switch | — | |
| Temperature switch | — | |
| Flow switch | — | |
| Control relay | — |
1.Control diagrams use ladder logic format
2.L1 and L2 are the power rails in ladder diagrams
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