SpecCalc Hub
Reference overview for common schematic symbols.
Electrical symbols let you read a schematic without seeing the physical device. A switch, fuse, motor, earth connection or resistor is normally represented by a compact symbol so the drawing stays readable even when the real installation is large.
This reference is useful for electricians, students, maintenance teams and buyers who need to understand what a drawing is describing before they compare parts, trace a fault or review a cable schedule.
The page is structured as a practical reference: start with the visible table, diagram and labels, then compare them with the exact connector, device, enclosure or symbol set in front of you.
Use the listed sources to confirm revision, naming and application context. Similar labels can hide different electrical limits, pin functions or test conditions, so the page should be treated as a guided reference rather than a universal standard text.
A resistor, capacitor and switch in one branch usually mean the designer wants timing, filtering or suppression, not just a plain on/off path. Reading the three symbols together is more useful than reading each one in isolation.
If you see earth, fuse and motor symbols on one feeder, the drawing is showing both protection and the connected load. The symbol tells you the device class, but not its final rating. The rating must still be verified in the schedule, datasheet or project notes.
Not always. The general function may be the same, but the exact graphic style and notation can differ between IEC, ANSI and manufacturer drawings.
No. Use the symbol page to identify the item, then check the schedule, datasheet and project notes for ratings and selection details.
Because many drawings reuse similar shapes for different contexts. The legend tells you how that project defines the symbol set.
Last reviewed: 2026-06-05
| Item | Simple symbol | Meaning |
|---|---|---|
| Resistor | --/\/\-- | Limits current or drops voltage |
| Capacitor | --| |-- | Stores electric charge |
| Inductor | --oooo-- | Stores magnetic energy |
| Switch | --o/ o-- | Manual or controlled open/close |
| Fuse | --[F]-- | Overcurrent protection component |
| Earth | ⏚ | Earth/ground reference |
| Transformer | coil || coil | Magnetic coupling between windings |
| Motor | (M) | Electrical motor |
This calculator provides an estimate for informational purposes only. It is not a certified engineering design, electrical safety approval, or professional installation recommendation. Always verify final decisions with a qualified professional and applicable local codes.