Hold-open systems (and accordingly also free-swing door closers and door drives with a hold-open function) on fire doors (fire protection or smoke protection doors) must automatically close the door element in the event of danger. For this purpose, fire detectors are required, usually for the fire parameter smoke. Smoke detectors must be used for hold-open systems for closures in escape routes. A distinction is made between fall detectors and ceiling detectors according to their position - in some systems, fall detectors are already integrated into the hold-open system, provided that it is located in the fall area. Depending on the installation situation, additional ceiling detectors are required:
SM= fall detectors; DM = ceiling detector
The preceding sketch serves as a guide, the actual type, number and arrangement of the required fire detectors can be found in the registration certificate of the respective hold-open system. In certain cases, the fall detector can be omitted in case 2a. For opening widths of more than 4 m, additional fire detectors are required.
The ceiling base to which the ceiling detectors are to be mounted is the raw ceiling or, if available, a closed suspended ceiling. In the case of smoke-permeable suspended ceilings, the raw ceiling surface is also the relevant ceiling surface.
Source: bauwion
