DorMag Pro wireless fire door magnet unveiled by Fireco

The majority of magnetic door retainers currently available on the market are characterised by being wired-in solutions. As such, the thought process behind the DorMag magnetic door retainer is that it would be wire-free. It’s installed behind any given door and, in practice, operated by battery packs in the form of three lithium-ion disulfide cells.

When the fire alarm’s triggered, DorMag Pro will release fire doors to close. ProHub is supplied with Fireco’s Site Manager software, which provides real-time information about the client’s Pro installation at different sites. This is accessible on any Internet device.

The ProHub is essentially a transmitter connected to the fire alarm panel. If the alarm’s triggered or the alert is triggered as well, it transmits a signal that’s between 433 MHz and 434 MHz (ie a regulated frequency here in the UK). It will trigger the unit to essentially pulse its magnet, unlatch the door and also cause the magnet to retract. The door is then no longer in a latchable state.

Importantly, the radio-activated device is not impacted by any noise. If the end user’s looking for a solution that’s independent of audio around the building, the radio option is probably the way forward.

On that note, the DorMag Pro is suitable for Category A (critical doors) as per BS 7273-4 when forming part of a critical system.

Matt Ball, product design engineer at Fireco, informed Fire Safety Matters: “The Pro unit is fixed to the wall, and the door keeper is fitted to the door. Magnetised together, they form a simple solution to hold open the door. Releasing the door is just as easy. When the unit receives a signal from the ProHub, the unit is automatically released. This sends a pulse to the electromagnet, briefly demagnetising the electromagnet and causing the keeper and the door to release. The magnet also retracts inwards, which is a key feature of the product. Once the magnet has retracted, you will not be able to hold the keeper on to it. It is now in a fail-safe state.”

Clients might ask: ‘Why not just have the current switched off to the magnet or the magnetism taken away from the magnet?’ Ball responded: “The problem is that this works by having a permanent electromagnet in there. A current is delivered to that magnet. As it’s a battery-operated device, if a pulse is continually fired through that magnet with a current flowing through it, the batteries are going to drain very quickly. A big part of the project is trying to overcome that, which is why you also retract at the same time. The key point is that, in that state, it’s now not using any excess power, only its quiescent (ie sleep) current to detect its transmitter.”

Fireco will be exhibiting at The Fire Safety Event, which runs at the NEC in Birmingham from 30 April-2 May. Visit Stand D110 in Hall 5.

*Further information is available online at www.fireco.uk