# Duct smoke detector plan symbol

Canonical URL: https://eloragrid.ai/symbols/iec-duct-smoke-detector-plan-symbol
Publisher: Elora Grid
Updated: 2026-10-28
Lookup label: DSD
Drawing use: GA
Reference families: IEC

## Symbol convention

Convention: IEC
Form: Duct smoke detector
IEC 60617 installation-plan style (architectural and topographical installation symbols); independently drawn, not certified IEC geometry or a database identifier.

Plan symbol for a smoke detector sampling air from a ventilation duct, drawn on the duct with sampling tube.

## In plain English

### What does Duct smoke detector plan mean?

Duct smoke detectors sample air flowing in a ventilation duct through a sampling tube, so smoke can be detected and air handling shut down or dampers closed. Plans draw the detector housing on the duct with a line across the duct for the sampling tube.

### A simple example

They are coordinated with mechanical drawings and with the fire alarm cause and effect, since their main job is usually plant control. A remote indicator is often required where the detector is in a ceiling void.

### What the drawings help you do

The symbol does not prove the detector provides room protection. Duct detectors are not a substitute for area detection.

### This particular reference

Plan symbol for a smoke detector sampling air from a ventilation duct, drawn on the duct with sampling tube. A room smoke detector protects a space; a duct detector monitors air in a duct for plant control.

### Terms

- Schematic: A drawing showing function and connections rather than physical appearance.

Concept diagram: Identify the device and form → Read the connections and state → Check the equipment reference
A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram.

- [IEC graphical symbols for diagrams](https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/)
- [Electrical installation design methodology and references](https://www.electrical-installation.org/enwiki/General_rules_of_electrical_installation_design)


## What it represents

Duct smoke detectors sample air flowing in a ventilation duct through a sampling tube, so smoke can be detected and air handling shut down or dampers closed. Plans draw the detector housing on the duct with a line across the duct for the sampling tube.
They are coordinated with mechanical drawings and with the fire alarm cause and effect, since their main job is usually plant control. A remote indicator is often required where the detector is in a ceiling void.
The symbol does not prove the detector provides room protection. Duct detectors are not a substitute for area detection.

## How to read it

- Check the duct and airflow direction on mechanical drawings.
- Look for a remote indicator.

## Information to show or reference

- Show duct location.
- Define plant shutdown action.
- Provide remote indicator.

## Important distinction

A room smoke detector protects a space; a duct detector monitors air in a duct for plant control.

## Facts

- Primary purpose: Shut down air handling or close dampers
- Companion: Remote indicator
- Exact standard graphic: Not reproduced here; confirm the form against IEC 60617 and the project legend

## Public references

- [IEC graphical symbols for diagrams](https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/) — IEC. IEC graphical symbol context for installation plans; independently drawn here.
- [Electrical installation design methodology and references](https://www.electrical-installation.org/enwiki/General_rules_of_electrical_installation_design) — Schneider Electric — Electrical Installation Guide. Installation design context: life-safety systems are coordinated with the building electrical design.

## Graphic scope

Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.