SD
Smoke detector plan symbol
Fire alarm plan symbol for a point smoke detector, drawn as a detector box with a smoke indication.
IEC
IEC · DSD
Duct smoke detector plan symbol
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.
- Schematic
- A drawing showing function and connections rather than physical appearance.
Read the source: IEC graphical symbols for diagrams · Electrical installation design methodology and references
IEC · Duct smoke detector
IEC 60617 installation-plan style (architectural and topographical installation symbols); independently drawn, not certified IEC geometry or a database identifier.
Shown as an independently authored educational illustration. Use the cited publication and drawing legend to verify the required drafting form.
GA · DSD
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.
A distinction that matters
A room smoke detector protects a space; a duct detector monitors air in a duct for plant control.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
IEC graphical symbols for diagrams
IEC graphical symbol context for installation plans; independently drawn here.
Electrical installation design methodology and references
Installation design context: life-safety systems are coordinated with the building electrical design.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. DXF uses unscaled drawing units; a GA envelope supplies no product dimensions, clearances or fabrication information. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
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