Magnetic door holders use electromagnetism to keep doors open, typically for fire safety purposes. A small metal plate on the door interacts with an electromagnet to achieve this.
The Basics of Operation
Here's a breakdown of how these devices function:
- Electromagnet: The core of the system is an electromagnet, which is usually mounted on the wall or floor.
- Metal Strike Plate: A metal plate is attached to the door. This plate is positioned to align with the electromagnet.
- Holding Action: When the electromagnet is energized (activated), it generates a magnetic field. This magnetic field attracts the metal strike plate on the door, holding the door open.
- Release Mechanism: Crucially, magnetic door holders are connected to a fire alarm system or life safety system. When the fire alarm is triggered, the power to the electromagnet is cut. This deactivates the magnetic field, causing the door to release and allowing it to close (often with the assistance of a door closer) to contain the fire and smoke.
Connection to Fire Safety Systems
The integration with fire alarm systems is a critical safety feature. This ensures that the doors automatically close during a fire emergency, helping to prevent the spread of smoke and fire.
Key Components Summarized
The following table summarizes the key components:
| Component | Function |
|---|---|
| Electromagnet | Generates a magnetic field to hold the door open. |
| Metal Strike Plate | Attached to the door; attracted by the electromagnet. |
| Fire Alarm System | Deactivates the electromagnet during a fire emergency, releasing the door. |
In essence, magnetic door holders are fail-safe devices that enhance fire safety by automatically closing doors when a fire is detected.
