Gooston provide a large selection of promotional resistance touch switch on sale
How to decide on Delayed Egress Hardware
Updated on August 18, 2013 Tom Rubenoff moreContact Author Example of Delayed Egress Signage | Source Introduction
Delayed Egress is a function of door hardware that does exactly what its name suggests: it delays people as they attempt to exit a secured space. When you’ve got experience installing hardware that complies with life safety code you will immediately understand that the very idea of delayed egress is a bit contrary to the entire philosophy of life safety because it applies to allowing folks to flee emergency situations without hindrance by locking systems or hardware. However, people have the suitable to try to defend themselves against theft of property, both physical and intellectual, and so the compromise of delayed egress was created.
Life Safety code says, in effect, “You can’t lock them in, but you may keep them in for fifteen (or so) seconds.” Aside from keeping people inside a space while they want to go away, delayed egress systems must otherwise comply with all other life safety code. Therefore all delayed egress systems:
Upon activation sound an alarm and keep the door locked from both sides for fifteen seconds
Should be automatically unlocked in the event of a fire
Must otherwise adjust to life safety and fire codes
Following is an excerpt from NFPA 101A Life Safety Code.
doors unlock upon actuation of the sprinkler system, any heat detector, or as much as 2 smoke detectors, and
doors unlock upon lack of power controlling the locking mechanism, and· an irreversible process (such as pushing the door or touch pad) releases the lock within 15 (AHJ can approve a delay of as much as 30 seconds) upon application to the discharge device (15 lbs for not more than 3 seconds), and
after release, locking shall be by manual means only, and
Must Otherwise Comply
Contrary to what some may believe, a delayed egress system is just not exempt from compliance with other life safety and fire code. For example, a hearth rated door must remain positively latched within the event of a fireplace; therefore if the only lock on a fire rated door is a delayed egress electromagnetic lock, this door is in violation. If one adds a UL Listed passage set to comply with the positive latching requirement, this will, in accordance with some Authorities Having Jurisdiction (AHJ) violate the “one motion” and/or “prior knowledge” requirements of life safety code since it will require those exiting in a panic situation to turn the lever after which push the door for fifteen seconds.
If you’d like to put in delayed egress, consult your local AHJ.
The Delayed Egress Process
All delayed egress systems work just about identically because they all must adjust to strictly enforced life safety code. The sequence of events that comprise delayed egress are roughly as follows:
When a person attempts to egress, they (hopefully) read the sign and start to push against the door or other initiation device
The timer may then time 2-3 seconds wherein nothing happens. This is named a nuisance delay. A nuisance alarm may sound through the nuisance delay.
The timer sounds the primary alarm and begins the irrevocable fifteen-second countdown to door release.
The system is reset. In some jurisdictions it could reset itself; in others it must be manually reset.
Most systems are also equipped with additional dry contacts that can be used to signal remote annunciators.
Securitron XDT Exit Delay Timer Module | Source Building Blocks of Delayed Egress
A delayed egress system consists of:
A specially designed, multifunction timer
Switches to show the system on or off, bypass the system for normal egress, and reset the system after it has gone through the delayed egress process
A fireplace alarm system interface
Many delayed egress systems are self-contained, having all these features built right in; it can be valuable to grasp each feature, what it does and how it does it.
Locks that meet the factors of securing the door from both sides are:
Specially designed delayed egress exit devices
Asylum or institutional function cylindrical or mortise locks
Cylindrical and mortise locks are rarely used for delayed egress, but it can be possible to do so if you really wanted to, though it can be difficult to make them comply with aspects of life safety code. Electromagnetic locks are the most popular for delayed egress applications because they are so easy to install, however delayed egress exit devices are often the most effective (or only) solution for some applications.
Delayed egress timing modules are specifically designed for use with delayed egress systems and all delayed egress systems have them. The timing functions the timer performs are:
Nuisance delay – when someone activates the system, local code usually allows a nuisance delay of up to 3 seconds (where permissible) before the 15-second irrevocable lock release process starts. There could also be a sounder that sounds an alarm during the nuisance delay period, giving someone who’s trying to get out an opportunity to vary their mind before the system goes into full alarm.
Exit delay – after the nuisance delay period, the timer causes an alarm to go off for 15 seconds. (Some jurisdictions may allow longer delay periods, but most allow only 15 seconds.) Some systems also offer an electronic verbal countdown to door release during this time. At the end of the 15 seconds the time releases the lock and the person is allowed to exit.
Automatic reset – in some jurisdictions the timer can rearm the system after a short time frame.
Manual reset, authorized exit system bypass, remote signalling and shutdown within the event of a fire are also functions performed by the timer module through an array of relay contacts.
Typically delayed egress systems in which the lock is an electromagnetic lock are powered by a low voltage, regulated and filtered power supply with battery back up. Delayed egress exit devices are usually powered by a power supply specifically designed to work with a certain exit device. It’s advisable to use the facility supply that’s recommended for the actual exit device.
On/Off Switch – used only when shutting down the system for service. Note: shutting down the system repeatedly for authorized egress or entry might be harmful to the system.
Authorized By-pass – used to allow people to exit or enter without triggering the delayed egress system
Reset – used only to reset the delayed egress system after it has completed the delayed egress process
Key switches, push buttons or access controls comparable to keypads or card readers can all be used as system switches. The on/off function can be performed by a maintained contact switch whereas all other functions can be accomplished through a momentary contact switch.
The initiation device is a switch that initiates the delayed egress process. Self contained electromagnetic delayed egress locks have the initiation device on board – a switch that detects door motion. The disadvantage to this kind of initiation device is that it can be activated from either side of the door – that’s, someone on the skin of the secured space can initiate the delayed egress process by pulling on the door.
Most self contained electromagnetic delayed egress locks feature contacts for an external initiation device. This device might be any kind of momentary contact switch, but the perfect sort of device is an exit device with an internal request to exit switch inside. This solution best complies with life safety code.
Delayed egress exit devices are basically their own initiation device. When the touch bar is depressed the delayed egress process is initiated.
As mandated by code, delayed egress systems have to be automatically deactivated by “actuation of the sprinkler system, any heat detector, or as much as 2 smoke detectors”. Therefore all delayed egress systems are equipped with terminals to be connected to the fire alarm panel via 2 conductor wire. If there is no such thing as a fire alarm system, technically speaking, one must install one before installing a delayed egress system.
If no fire alarm is present in the building, there are smoke detectors in the marketplace with on-board dry contacts that would do the job of deactivating the delayed egress system. Consult your local AHJ to see if that is a solution she or he will condone .
SDC 1511S Delayed Egress Electromagnetic Lock | SourceSecuritron IMXDA Delayed Egress Electromagnetic Lock | Source Self-contained Electromagnetic Delayed Egress Systems
The best way to put in delayed egress on an opening is to make use of a self contained delayed egress electromagnetic lock. At right are shown two examples.
On board the magnet is the delayed egress timer and all of the requisite electrical connections needed to adjust to life safety code.
The initiation device for a self contained delayed egress electromagnetic lock is usually a door motion sensing switch that’s integral with the lock. One simply pushes on the door to start the delayed egress process. As mentioned previously, it is also possible with this arrangement to drag the door and initiate the delayed egress process from the wrong side.
To remedy this example, one can use an external initiation device, equivalent to a regular panic bar with a request to exit switch inside. If access from the outside is required, one can provide a locking trim on the outside and a switch (key switch or other access control) to bypass the delayed egress system. If an electrified trim is used, the same access control that releases the delayed egress system can release the trim.
Basically the identical solution can be utilized on a fire rated door. Use a fireplace rated exit device with a request to exit switch in it for an initiation device. Then you may have your fire rating and your delayed egress magnet, too.
If there may be a fire rated exit device already on the door, there might be a retrofit request to exit switch available for it. Therefore on a door that already has a fire rated exit device, a self contained electromagnetic delayed egress system may be the best solution to go. Just install a request to exit switch in the bar and install the delayed egress mag lock and you are good to go – so long as your local AHJ approves.
Advantex Exit Device with “EE” Delayed Egress Option | Source Delayed Egress Exit Devices
A self contained delayed egress exit device is sort of as easy to install as a self contained electromagnetic delayed egress lock. Both offer much the same features – which makes plenty of sense given the code governing delayed egress is so specific.
All major exit device manufacturers offer a grade one exit device with delayed egress. The system usually consists of a more or less standard exit device that has an on-board exit delay timer with all the necessary features, an internal, electrically-operated device that keeps it locked, a key switch, a power supply and delayed egress signage. They’re all available in panic rated and fire rated versions.
Exit devices are inherently fail secure (mags are always fail safe)
Does not take up space in the opening
AHJ may hate mag locks
Yes it’s true: there is no such thing as a fail secure electromagnetic lock. There are mag locks with battery back up, but when the battery runs out the mag will probably be unlocked while the exit device will still be locked. If the door must provide free egress from one side and remain secured from the opposite with or without electric power, the exit device is the strategy to go.
Let’s face it, delayed egress mag locks are ugly. Of course, so is delayed egress signage, but it’s important to have the signage – you do not have to have the mag. Many end users prefer the look of an exit device over a mag. And should you should have an exit device anyway, making it a self contained delayed egress exit device may simply the job while providing a cleaner look.
The American Disabilities Act (ADA) mandates that openings be at the very least eighty inches tall – that would be six feet, eight inches of clear space to walk through when the door is open. In case your door is lower than six feet, eleven inches tall it may not be possible to install a delayed egress magnet and comply with ADA. There’s a minimum of one delayed egress magnet that is designed to be installed on the pull side and thereby could be a workaround for this situation.
Following the letter of the life safety code, one is just not purported to drill holes through a fire rated door except in a fireplace rated shop. This alone is reason enough to your local AHJ to throw a piece of hardware off a job, i.e. the mag lock. A method around that is to make use of a surface mounted bracket to carry the armature of the mag, but if the AHJ just would not like mag locks, the best thing to do is to make use of something else.
BA-XDT Delayed Egress Timer Module with Box and Sounder. | Source Delayed Egress Systems from Components
It isn’t possible or advisable to put in delayed egress on every door. Some doors already do not adjust to life safety code and their non-compliance is only made worse by the addition of delayed egress. Yet there are situations where a non-standard opening is approved and later requires a delayed egress system. There are components available on the market that might help.
Sometimes, too, when retrofitting a delayed egress system to an existing door, one can utilize some or all of the prevailing hardware through the use of components to convert the opening to a delayed egress opening.
Considered one of my favorite components for conversion of a door with an existing electromagnetic lock is the Securitron BA-XDT delayed egress system in a box. You get the sounder, the signage, and the timer module in a single package. The unit could be easily mounted above the door or high on the wall nearby. It requires as well as an initiation device, reset, on/off and bypass switches and a regulated and filtered power supply. Several manufacturers make similar products.
On doors too narrow to accommodate a self contained delayed egress exit device, several companies make delayed egress exit devices with remote timer modules. Some include an on-board keypad for reset, by-pass and on/off functions while others are prepared to just accept a standard mortise cylinder.
Removing the timer module from the device allows the device to be cut shorter, thereby allowing installations on narrower openings.
Source AHJ On Board
I cannot stress enough how important it is that the Authority Having Jurisdiction be consulted whenever one plans to install a delayed egress system. Before you call the AHJ, take the time to familiarize yourself and understand exactly how a delayed egress system is presupposed to work. Be sure your AHJ is on board with your plan, otherwise you might find yourself with a big and expensive paperweight.
view quiz statistics Related
Door ImprovementsHome Improvements Door Hardware Knobs Levers| Buy Online
by Ken Kline3
Door ImprovementsUse barn style sliding doors to boost decor, save space
Door ImprovementsStorm Door Installation Instructions for Installing a Storm Door
by Dan Harmon4
Door ImprovementsWhich is the perfect Keyless Door Lock? Four RFID height:75px” class=”thumbphoto”>Door ImprovementsWhat Do The Numbers On My Key Mean?
by Tom Rubenoff14
Gooston provide a large selection of promotional resistance touch switch on sale