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

SNDR

IEC

Fire alarm sounder plan symbol

Fire alarm sounders are drawn as a horn shape or a square with a sound mark, at wall or ceiling positions throughout the building. Their spacing is set by the required sound pressure level above ambient in each area.

Drawing use: GA
Application: Installation & communications
Reference family: IEC
Form evidence: Fire alarm sounder. 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 schematic siren or buzzer symbol represents a component; this plan symbol marks a building alarm device.

Full reference

HAN1S

IEC

Audible siren

A siren indication identifies an audible alarm output with the documented operating role.

Drawing use: Schematic
Application: Control circuits
Reference family: IEC / Manufacturer
Form evidence: Audible siren. Autodesk IEC-60617 Symbol Preview — Audible indication and protective component forms; vendor family reference, not certified IEC geometry or database identifier.

A distinction that matters

The symbol alone does not prescribe tone pattern or evacuation meaning.

Full reference

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