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 dimmer switch plan symbol

A wall dimmer in US plan practice is drawn as S with subscript D, sometimes with a wattage note. The switch leg links it to the dimmed group, and three-way dimming is shown by pairing SD with S3 or with a companion device.

Drawing use: GA
Application: Installation & communications
Reference family: IEEE / ANSI
Form evidence: Dimmer switch, SD. 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 dimmer uses a variability arrow on a switch mark; the US form uses the D subscript.

Full reference

IEC

Dimmer switch plan mark

A dimmer varies the power delivered to luminaires using phase-cut electronics or a control signal. IEC-style plans typically draw the switch mark with an oblique arrow or a small adjustment mark to show continuous variation, and the switching line links it to the dimmed group.

Drawing use: GA
Application: Installation & communications
Reference family: IEC
Form evidence: Dimmer switch. 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 one-way switch has no variability mark; the dimmer adds continuous control of light output.

Full reference

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