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 · MSD
Multi-sensor fire detector plan symbol
Fire alarm plan symbol for a detector combining smoke and heat sensing, often switchable between modes.
In plain English
What does Multi-sensor fire detector plan mean?
Multi-sensor detectors combine optical smoke and heat sensing, and sometimes carbon monoxide, in one head. Plans draw the detector box with both smoke and heat marks, or a tag such as MS, so the installer fits the correct head.
A simple example
These detectors reduce false alarms while keeping smoke sensitivity, and some can be programmed to act as heat only at certain times. The plan symbol therefore often sits alongside a cause-and-effect note. The symbol does not show the programmed mode. The fire alarm configuration records that.
What the drawings help you do
Check programmed modes in the configuration notes. Confirm the base type matches the panel protocol. A single-sensor smoke detector has one mark; the multi-sensor shows both smoke and heat elements.
This particular reference
Fire alarm plan symbol for a detector combining smoke and heat sensing, often switchable between modes. A single-sensor smoke detector has one mark; the multi-sensor shows both smoke and heat elements.
- Signal
- Electrical information passed between devices, rather than necessarily the main power supply.
- 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 · Multi-sensor 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 · MSD
What it represents
Multi-sensor detectors combine optical smoke and heat sensing, and sometimes carbon monoxide, in one head. Plans draw the detector box with both smoke and heat marks, or a tag such as MS, so the installer fits the correct head.
These detectors reduce false alarms while keeping smoke sensitivity, and some can be programmed to act as heat only at certain times. The plan symbol therefore often sits alongside a cause-and-effect note. The symbol does not show the programmed mode. The fire alarm configuration records that.
How to read it
- Check programmed modes in the configuration notes.
- Confirm the base type matches the panel protocol.
Information to show or reference
- State sensing elements.
- State programmed mode.
- Tag loop and address.
A distinction that matters
A single-sensor smoke detector has one mark; the multi-sensor shows both smoke and heat elements.
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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