# Magnetic door holder plan symbol

Canonical URL: https://eloragrid.ai/symbols/iec-magnetic-door-holder-plan-symbol
Publisher: Elora Grid
Updated: 2026-10-28
Lookup label: DH
Drawing use: GA
Reference families: IEC

## Symbol convention

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

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.

### Terms

- 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.

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

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.

## Important distinction

A door contact only reports door position; a door holder keeps a fire door open until alarm.

## Facts

- Fail state: Releases door on power loss
- Interface: Fire alarm relay or module
- 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.