Hi,
Has anyone any experience in wiring up a 24v MAGNETIC Fire door release. Ideally I would like to link it to the mains interlinked fire alarms that I have around the house (Screwfix). Would this be possible? ... and is it safe?
cheers Colin
No, but they are also available in 240v which could simplify things somewhat.
In article , Colin writes
I've just fitted a number of these, I assume you mean the ones with a large 10" X 2" electromagnet rather than the solenoid lock releases? The only worry I had was that due to the positioning at the top of the door then a determined person may be able to exert enough force lower down to still force the door open, but there again that could apply to any lock. The plate that fixed to the door was held on by 8 X 1" screws and was easy enough to fit. The magnet was fitted to the door frame and was not so easy, on a new install it would probably be much easier and neater. I had to cut out a 10" section of the trim around the frame to accommodate the bracket but there was only about an 1" of the frame to screw to, it would have been stronger if this could have been made thicker, there was a good 1" gap between the frame and the brickwork. Cabling was another issue, most of the doors I were below a false ceiling and a short vertical run of conduit was all that was needed but one was in a recess and took a bit longer. You say fire alarms, are these just inter linked smoke detectors or do they go to an alarm panel? If they are just the former then maybe some one produces a relay interface for them or if an alarm panel does it have an out put you could use to drive a relay?
They would obviously unlock when power was removed so even if you had battery back up there could come a time when they opened themselves so I wouldn't use it as my only lock on an outside door, secondly how are you going to open them at other times? A time delayed push button maybe the easiest.
Caveat: I am a radio engineer by trade not a chippy or lock smith so take the above as non professional advice, it was just that we had a customer that needed these as an extra to something we were already supplying, we put proximity card swipes on the locks, remarkably cheep they were too, almost worth looking at for home use, if the kids loose a key just disable the card and give them a new one.
Take a look at http:/
Do you mean the ones that hold self closing doors open until triggered when they release the door or do you mean the magnetic locks?
It's quite possible with either but you would need to make/obtain a fairly simple interface between the sensor wire (which I think is only low voltage anyway) and your door control.
I was hoping for one that holds self closing fire door open until the smoke alarm was triggered. I am not sure what the BCO would think... but they have them in public buildings.
I guess that the smoke alarms have a 240v interlink, (there is no central control, they are daisy-chained one of the other)and I am guessing that the interlink goes live when one of the smoke alarms are triggered. Both of these factors make it more complex than first appears (?)
Colin
In article , Colin writes
In which case disregard at lot of what I said earlier!
I would imagine the BCO would be happy with your idea plus a door closer of some kind.
Find out who manufactures the smoke alarms and see if they provide an interface that will give you dry relay contacts that are triggered when the alarm activates and if they do or can advise you on how to make one then it should be easy enough. You would still need a release switch by each door though for manual operation, not a problem.
You can use a small relay of appropriate rating.
I have a door holder with the supply running through a relays fired from my intruder alarm panel in both Alarm (fire) ond Set conditions. That way the door closed as soon as the alarm is set. It's the door to my garage so having it close automatically whenever I'm out is brilliant.
Thanks, I'll try that.
Sounds great. Is there a risk of being locked out in the event of a power cut with such a system?
Colin
The interlink is frequently low voltage, so it can operate after mains failure on the low voltage batteries.
My mains linked smoke alarms have an optional relay base that I've used to activate a fire zone on my intruder alarm. Such a device could easily operate the latches.
I didn't actually particularly want to use the surface mounted base it comes in, so removed the internal gubbins and stuck them in a wiring accessory box next to the alarm. This probably invalidates some sort of approval, but it is safe in my case, and I'm not actually required to have the alarms, so they aren't subject to building control.
Christian.
If on a door that self locks then yes, I suppose so. In my case it the door from the Garage to the Utility area. I have a magnetic holder because I do lots of work in the garage and want the door open. When I set the alarm I go out through the front door of the house and if I've forgotten to close the garage door it closes automatically - two reasons... 1. it's alarmed and so need to close to enable the alarm to set and 2. fire/smoke risk as it's a garage door.
Any recommendations as to where to buy a door release mechanism?
I've bought and installed a door closer for the front and rear doors of my house. Great relief from having to shout at the kids all the time!
When I have to carry something awkward into the house (the wife... :-), having the door wishing to close within about 1 second of opening is a nuisance.
Hence I was thinking of some sort of electromagentic latch incorporated into a circuit with (say) a 3 minute timer. Once energised the latch holds against the closer for about 3 minutes, then the power releases and the door closes as normal.
But where to pickup an electromagnet capable of thwarting a door closer...
Thanks in advance
Mungo
In article , Mungo Henning writes
Try taking a look at
This is the normal ( 9" X 2" approx.) 12V electromagnet and will certainly hold against your door closer. @ £20 ish each A lot cheaper than RS @£200 each, but then every thing is!! Unfortunately there is no picture on the site but it may be worth while giving them a call 01189440123. Depending on how you want to fix them you may need a Z&L bracket set as well.
"Mungo Henning" wrote | Any recommendations as to where to buy a door release mechanism? | But where to pickup an electromagnet capable of thwarting a door closer...
Any electrical wholesaler who sells fire alarm bits.
Owain
In article , - writes
Where did you get your prices - looks like a phone for quotation type outfit.
In article , fred writes
I recently installed some but can't remember exactly how much we paid, company money not mine!!
-------------- Firstly, the power source for the detectors is 24VDC supplied by the fire alarm panel. (you can't believe the amount of times sparkies hook up to the wiring thinking it is mains and bugger everything up)
I assume you are considering the Fire Panel and detectors on page 186 of the latest Screwfix catalogue. It doesn't give much in the way of details but I'm sure Screwfix will provide you with contact details for the manufacturer. What you need to know is how many door holders you plan to use and how much current they require. The manufacturer can then advice you if their unit has sufficient spare DC capacity. If it hasn't, which is likely, they can probably either sell you an auxiliary supply or point you as to where you can get one. It's also a good idea to ask which holders they recommend.
As you are intending to apply these in a house then it need not be complex to wire.What you must decide is whether or not you want ALL doors to close on any alarm or just those in that zone. If you want it done zone by zone then you must ask the manufacturer if their unit can do that. In any event, the wiring is simple. One pair for the detectors per zone and one pair for the holders. The detectors get wired into their respective zone inputs and the holders can all be connected to the Aux Fire Relay (for all close at once) or, as zones they can be connected to the individual zone alarm relays, if available. (note: the relays are voltage free, typically, so you would be using them to switch either an auxiliary 24VDC source or the internal 24VDC source - just wiring up to the relays does nothing if you haven't also connected the voltage. All these Units come with wiring diagrams so I'm sure you'll suss it out) Unless you have some particular reason for not releasing all the doors in one go then that is what I would do in something as small as a house.
And remember to use the right type of detector for each area or room.
NORBAIN??!!!!!
Forget them. They won't give you a catalogue if you're not trade and even then they won't deal as a one off.
Electrical wholesaler is a good idea though. Also try A+A Security Wholesalers (part of the Newey & Ayre group) or Gardiner Security. Those type of wholesaler will usually supply one offs to non trade buyers.
If you know of anyoen with access to an RS account they will have or you can go direct.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.