FACP
Fire alarm control panel plan symbol
Plan symbol for fire detection control and indicating equipment, the panel that monitors detectors and drives alarms.
IEC
IEC · DH
Magnetic door holder plan symbol
Plan symbol for an electromagnetic door holder that keeps fire doors open and releases them on alarm.
In plain English
What does Magnetic door holder plan mean?
Electromagnetic door holders keep fire doors open during normal use and release them when the fire alarm operates or the supply fails. Plans draw a small box against the wall at the door swing with an M or DH tag, linked to the fire alarm interface.
A simple example
The holder is fail-safe: loss of power releases the door. The plan should show the interface relay or module and the supply, so the installer can wire the release correctly. The symbol does not show holding force or the door closer, which is a door hardware item.
What the drawings help you do
Check the door swing and holder position. Find the alarm interface that releases it. A door contact only reports door position; a door holder keeps a fire door open until alarm.
This particular reference
Plan symbol for an electromagnetic door holder that keeps fire doors open and releases them on alarm. A door contact only reports door position; a door holder keeps a fire door open until alarm.
- Coil
- A wound conductor that can produce a magnetic field when energised.
- Terminal
- An identified point where a conductor connects.
- 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 · Door holder
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 · DH
What it represents
Electromagnetic door holders keep fire doors open during normal use and release them when the fire alarm operates or the supply fails. Plans draw a small box against the wall at the door swing with an M or DH tag, linked to the fire alarm interface.
The holder is fail-safe: loss of power releases the door. The plan should show the interface relay or module and the supply, so the installer can wire the release correctly. The symbol does not show holding force or the door closer, which is a door hardware item.
How to read it
- Check the door swing and holder position.
- Find the alarm interface that releases it.
Information to show or reference
- Show interface module.
- State supply voltage.
- Coordinate with door hardware schedule.
A distinction that matters
A door contact only reports door position; a door holder keeps a fire door open until alarm.
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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