Unobtrusive design

The ZF-MR2 is an unobtrusive door retaining unit designed to hold fire doors, in the open position, on busy corridors, yet on a fire condition allowing them to automatically close. The unit consists of two separate parts, a door plate which is fitted to the fire door and a solenoid usually installed on the wall, or (using the bracket supplied separately) to the floor. Doors are held in the open position, against self-closing mechanisms, when the solenoid is energized and are automatically released when current is switched by the fire alarm panel. The solenoid unit is housed in a strong di-cast enclosure. A manual release button, which can be fitted to either side of the solenoid casing allows the door to be easily released at any time, without operating the fire alarm system.

Unique spring release

The solenoid core features a unique spring release design which, whilst providing a holding force of 40 Kg ensures reliable 'non stick' operation by reducing residual magnetism to a minimum. Two versions of the release unit are available, the 24 volt DC device, powered by either a dedicated DC supply, or a transformer rectifier arrangement and a 240 volt AC unit powered directly from the mains supply. An added advantage of the mains powered version is that should a public power supply failure occur, as a fail-safe measure, all fire doors will automatically close. Most fire detection and alarm control panels, will require an intermediate mains relay, to switch current from the 240 volt AC unit.

Easy to wire terminals

Door release units are wired as separate circuits, from the fire detection and alarm control panel and are controlled either on a system bases where all doors in the building close on a common fire signal, or by zonal fire outputs from the control panel, releasing the doors in the affected part of the site only. Large fixed terminal blocks are provided in each unit for ease of installation.

Downloads

• Datasheet