Fire Protection

Hold-open systems for fire doors and gates are part of the product category of preventive fire protection and have the task of ensuring the safe operation of fire doors and gates. These systems ensure that fire doors are kept open during normal operation, but close automatically in the event of a fire to prevent the spread of fire and smoke.

Components of a hold-open system

A hold-open system usually consists of several components that work together to ensure the system functions:

Smoke detector: 

These are used for fire detection and are the central element for identifying the trigger for closing the door. In the event of smoke or fire, they send a signal to the hold-open system.

Control unit: 

The control unit is the ‘brain’ of the hold-open system and coordinates all other components. It receives signals from the smoke detectors and gives the command to close the door. It also monitors the proper functioning of the entire system.

Hold-to-run switch/manual switch: 

The hold-to-run switch can be used to trigger the hold-open system manually to close the fire door immediately. This is particularly important when a manual release is necessary faster than the automatic smoke detection.

Hold-open device (e.g. electromagnets): 

The hold-open device, often electromagnets, keeps the fire door open during normal operation. As soon as the signal to close the door is given by the smoke detector or the control unit, the magnetic current is interrupted and the door closes by means of a mechanical closing mechanism.

Closing mechanism:

The actual closing function of the fire door or gate is ensured by a closing mechanism that causes the door to close after the hold-open system has been triggered. This can be done, for example, by a door closer or a counterweight.

Reliable closing of fire doors

The hold-open systems are designed and installed in such a way that they allow for an open passage on the one hand and ensure reliable closing of the fire doors or gates in the event of a fire on the other. This is particularly important in public buildings, production plants, hospitals and all buildings with high fire protection requirements.