Side-by-side reference

Understand the difference.

Compare the meaning, drawing context and source references of two entries. A similar graphic or shared abbreviation does not establish equivalence.

First referenceCompare with

IEEE / ANSI

ANSI smoke detector plan symbol

US fire alarm plans commonly draw smoke detectors as a circle tagged SD or a square with an S, with a subscript for duct or beam types. The form follows the project legend, which often adapts NFPA-based fire alarm conventions.

Drawing use: GA
Application: Installation & communications
Reference family: IEEE / ANSI
Form evidence: Smoke detector, US plan. US architectural electrical plan practice in the ANSI Y32.9 lineage, read alongside IEEE 315 context; independently drawn, not a certified IEEE or ANSI graphic.

A distinction that matters

The IEC-style smoke detector plan symbol serves the same purpose with a different internal mark.

Full reference

IEC

Smoke detector plan symbol

Point smoke detectors are drawn on fire alarm layouts as a square or circle with a smoke mark inside, such as wavy lines or the letter S, at their ceiling position. Each symbol is usually tagged with its loop and device address so the plan doubles as the commissioning record.

Drawing use: GA
Application: Installation & communications
Reference family: IEC
Form evidence: Smoke detector. IEC 60617 installation-plan style (architectural and topographical installation symbols); independently drawn, not certified IEC geometry or a database identifier.

A distinction that matters

A heat detector responds to temperature, not smoke; it uses a different internal mark.

Full reference

Original educational previews. Follow the source references on each full entry for the appropriate standard or selected product.