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Fail Safe and Fail Secure Electric Locking Devices

Definition

Basically:

  • Fail Safe = power off, it’s unlocked
  • Fail Secure = power off, it’s locked

Electric locking devices include:

  • Electric strikes
  • Electromagnetic locks
  • Electromechanical locks
  • Electrified exit devices

Most electric strikes are sold fail secure by default. For example,
if you order a Von Duprin 6123 24V US32D, and architectural grade 1
electric strike, it will most likely come fail secure regardless if
it has Von Duprin’s “FSE” (standing for fail secure) in the part number
or not. The part number in the Von Duprin price book does not include
“FSE.” To be sure you are going to get a fail safe electric strike (not
the norm) if that is indeed what you want, in this instance you would
include Von Duprin’s abbreviation for fail safe, “FS”, for example,
6123 -24V-FS-US32D.

All electromagnetic locks are fail safe because they are always
unlocked when disconnected from the power source. Using a battery
back-up does not make an electromagnetic lock fail secure because
the magnet would still be unlocked if the power was disconnected.
Later in this article it should become apparent why this detail
is important for reasons of life safety.

Electromechanical locks include standard cylindrical or mortise
locks that have been electrified and locks that are designed to
only work electrically, such as an electric bolt lock. They are
sold in equal amounts fail safe and fail secure.

Electrified exit devices come in a variety of functions, including
those with electric latch retraction and those with electrified outside
trim control. Electric latch retraction devices are fail secure whereas
exit devices with electrified exterior trim control might be either
fail safe or fail secure.

Application

Electric Strikes

Fail safe electric locking devices are used wherever doors must remain
unlocked in the event of a fire or other life safety emergency. If
the opening is fire rated, it must be positively latched by a fire
rated device in the event of a fire. Therefore there is no such thing
as a fire rated fail safe electric strike because if the power were
off (as it might very well be during a fire) the door would not be
positively latched. If you install a fail safe electric strike on
a fire rated opening, the inspector can require you to replace the
entire doorframe.

Technically, fire rated door frames cannot be modified in the field,
but must be prepared for hardware (including architectural grade electrified
hardware) in a fire rated shop. I have never heard of this being enforced,
nevertheless, the AHD (Authority Having Jurisdiction) could enforce
it, so if you plan to modify a fire rated opening in any way it might
be a good idea to get the local fire marshal on board during the planning
stages.

In general, a fail safe electric strike is a good choice for a “non-fire-rated
door that must be unlocked in the event of an emergency other than
a fire” kind of application.

Fail secure electric strikes are a good choice for exterior or other
non-fire-rated doors where remote release or electronic access control
is needed. They are pretty reliable, usually not difficult to install,
and relatively inexpensive. One of the chief disadvantages of an electric
strike is that, on out-swinging doors, they provide an opening into
which a burglar can insert a tool, such as a tire iron, to pry directly
on the locking device. A latch guard is a minimally effective deterrent
to this kind of attack.

(Exterior doors are almost never fire rated, and if they are, usually
it is because all the doors on the job were ordered to the same spec,
not because they have to be.)

Electromagnetic Locks

Some inspectors and fire marshals just don’t like electromagnetic
locks. This is another reason to get your local AHD on board from
the start. But if your AHD is not an obstacle, a mag can be a good
solution for existing fire rated doors with existing fire rated hardware
on them. The fire rated hardware can stay to keep the door positively
latched in the event of a fire, and the mag is inherently fail safe,
so it could be a good choice for stairwell doors, greatly simplifying
the application. The problem with mag locks is that they lock both
sides of the door simultaneously. That means you have to deal with
both a means to get in (access control) and a means to get out (presence
detector and redundant exit pushbutton, for example).

If the door already has an exit device, it is probably possible to
install a request-to-exit (RX) switch in the bar to allow exit by
a fully mechanical means – a factor which might make the AHD happier
with the installation. The AHD will also want to know that all electromagnetic
locks are wired so that the fire alarm will cut power to them in the
event of a fire.

Since a mag lock does not positively latch, it cannot be legally
used alone on a fire rated door. There must be a fire rated positively
latching mechanism in addition to the mag.

Delayed egress electromagnetic locks can also be used for access
control on egress doors while helping to prevent unauthorized exit.
For more information on delayed egress, please visit:

Electromagnetic locks are not too expensive and are very easy to
install. Because they are inherently fail safe, you may want to install
a battery back-up system so that they remain locked during routine
power outages.

Electromechanical Locks

Fail safe electrified standard locks are ideal for stairwell doors
(unless they already have exit devices) because they remain positively
latched when unlocked. Many states and localities require that stairwell
doors be unlocked in the event of a fire, and because all interior
stairwell doors are fire rated, they must also remain positively latched.

In order to replace a standard mechanical lock with an electrified
one, a raceway must be drilled through the door from lock side to
hinge side so that wire can be run to power the lock. If you guessed
that, technically speaking, this voids the fire rating on a fire rated
door, you were correct. Be sure to clear all modifications to fire
rated openings in advance with the local AHD.

Electric bolts are usually used as a last resort when no other application
will work, such as when retrofitting access control to automatic sliding
doors. Electric bolts are most commonly used in prisons, where egress
concerns are treated rather differently than commercial applications.
They can also be used in place of electromagnetic locks, however electric
bolts designed for commercial (rather than detention) applications
are less secure, less durable and more difficult to install than mag
locks.

Electrified Exit Devices

If a door has an existing exit device or an architect has specified
an exit device for an opening, it is because the capacity of the building
in terms of the number of people therein warrants the use of an exit
device. Therefore it is unwise to replace an exit device with another
kind of hardware.

Luckily, many exit devices can be electrified in the field either
by replacing internal parts of the device or by adding an electrified
trim (outside handle or lever).

As I mentioned earlier, exit devices can be electrified in one of
two ways:

  • Electric latch retraction
  • Electrified outside trim

Since electric latch retraction is always fail secure, it might not
be a good choice for stairwell doors unless it was always unlocked
from the stairwell side. If that were the case, the only probable
purpose for the electric latch retraction would be to unlatch the
door for a power operator (automatic door opener).

Electric latch retraction is ideal on exterior pairs of doors where
fail secure access control is required. Since exterior pairs of doors
are often equipped with concealed vertical rod exit devices, installing
electric latch retraction is often the easiest and best alternative.
Electric latch retraction (or electric remote dogging) is also very
compatible for use with power operators.

The down side of electric latch retraction, in addition to being
expensive in its own right, is that it often requires a special and
expensive power supply. Sargent 56 prefix exit devices are an exception,
requiring only a minimal power supply for activation.

Fail safe electrified exit device trim is a good alternative for
stairwell doors whether they already have an exit device or not. For
one thing, since the wire powering the trim is run through the exit
device, no modification of the fire rated door is necessary.

Electrified exit device trim is also available fail secure, and is
often a less expensive alternative to electric latch retraction where
simple access control is the goal.

Note on “Continuous Duty”

I have been asked, ‘What is the difference between fail safe and
continuous duty?’ Fail safe applies to the function of the device
as described above whereas continuous duty simply means the strike
is built to be constantly powered if so required. The confusion arises,
I think, because all fail safe locking devices are continuous duty.
This is because a fail safe device must have power to be locked. Fail
secure electric strikes that are connected to a timer and powered
all day to remain unlocked also must be continuous duty rated. Therefore,
not all continuous duty electric strikes are fail safe, but all fail
safe strikes are continuous duty.

Rule of thumb: almost every kind of electric locking device that
runs on DC current is continuous duty.

The Wacky World of Wireless Access Control Locks

Wireless access control locks are at the leading edge of door hardware evolution, creating hybrid devices that are both credential reader and locking hardware all in one. Some of these locks are designed to integrate with existing access control systems without the need to run cable back to the panel from the door; others interface with their own software on the end user’s computer or computer network using a wifi gateway.

Left: Dorma Kaba Eplex ………… Right: Alarm Lock Networx

The Independent Systems

Alarm Lock and Dorma Kaba are two manufacturers that offer wireless access control locks with proprietary software designed only to control and monitor these locks.  This represents a step up from standalone programmable locks that needed to be visited with a notebook computer or handheld programmer for programming and audit trail download purposes. The locks connect via a wireless router or gateway to a single PC or to a server on the end user’s computer network.

The Alarm Lock Networx product can also be integrated into a few access control systems; see the Alarm Lock Networx web site for details.  The Dorma Kaba wireless Eplex lock is compatible with Dorma Kaba E-Enterprise software.

These independent solutions are good for folks who want to upgrade from mechanical locking systems to electronic access control, offering full featured access control capabilities, near-instantaneous reporting and monitoring and requiring very little wiring to install.

If, however, the end user has an existing access control system that they would like to expand, using the Alarm Lock Networx software or Dorma Kaba E-Enterprise software would mean adding a second access control system – a complication many end users would like to avoid.

In the past, when a facility wanted to expand their access control system their access control company would be called in to run wire and install credential readers and the door hardware installer might be called in to install electric locks or strikes to be controlled by these new readers. Today, however, the door hardware installer can install wireless access control locks that can be integrated into the end users existing system.

But wait! Not so fast, there, champ.

Left: Schlage AD-400 ………. Right: Sargent IN120

The Integrators

Allegion and Assa Abloy are two major lock manufacturers that offer wireless access control locks that integrate with existing access control systems. This means that the end user can program these locks using the same access control software they are currently using.

Using the Allegion AD series wireless as an example, a single interface panel can allow up to sixty-four of these locks to the panel. There is actually some wiring involved with wireless locks: the interface panel (or wifi gateway) must still be wired to the main access control panel. This is the great attraction: that one can greatly expand an access control system without spending a lot of time and money on wiring. A wire is run from the access control panel to the interface panel in a distant wing of the building, and then the interface panel (or a few of them) communicate with all the locks in that wing.

Conflict arises from the very fact that these locks are designed to integrate with existing systems. Over the last several decades, access control systems have become big business. Traditionally, for every door in the system, the access control company sells a reader. In addition, an expansion module may be needed at the access control panel. If we install sixty-four wireless locks and integrate them into the existing access control system, it can be said that we just deprived the access control company of the sale of sixty-four readers.

Access control does a lot more than control access these days. Access control, environmental control systems, fire and security alarms, elevator control, employee time and attendance, student meal plan administration and other systems may all be incorporated into the same system, run by enterprise level software on a server on the end user’s computer network. You might say the access control company that owns the rights to the software and manufactures the access control panel is in a very secure position. Extricating one access control company to replace it with another could be a monumental task, involving every person whose life the system touches.

What can access control manufacturers do about these wireless locks being attached to their systems? Plenty. They can update their software so that these locks are incompatible. They can charge the end user a licensing fee for every lock that is added. In short, they can make the addition of wireless access control locks to their system expensive or impossible.

Both Allegion and Assa Abloy have made agreements with access control manufacturers that allow their products to be added to existing access control systems. Allegion has a range of agreements with various manufacturers limiting to whom Allegion wireless access control products can be sold. In many cases Allegion wireless products can only be sold to the access control company with whose system they will be integrated. Assa Abloy wireless access control locks can only be sold to their designated Certified Integrators. It is through these channels that wireless access control locks make it onto job sites.

Because of these sales limitations, bidding on jobs that specify these kinds of locks can be complicated. Bidders often find they must exclude specified wireless access control locks from their bid because they are unable to buy them. In the case of Assa Abloy products, some bidders may elect to take the online course and become a Certified Integrator. In the case of Allegion, they might be fortunate enough to be bidding on a job in which the access control manufacturer has no agreement with Allegion, and the job can therefore be freely bid. In either case, however, it is a more complicated process than simply pricing out a piece of door hardware.

 





Evolution or intelligent design? Wait, did you say, ‘intelligent?’

 

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Field Reversing the Precision E2203 SVR Exit Device

The Precision E2203 is a Surface Vertical Rod exit device with a solenoid in the head that controls the outside lever trim.  Ordered complete with trim: part number is E2203 × 4908A, specify door width, finish, handing, fail safe or fail secure.  The right thing to do is to order it fail safe or fail secure and handed at the factory for your application. 

But… let’s say for the sake of this article that you ordered the device and did not specify handing or fail safe / fail secure. You might find yourself needing to field reverse the handing.  Here is what you need to know.

Handing

Changing the hand on the basic 2200 device is not very difficult, but changing the hand on the E2200 is fairly difficult, and requires skill, patience and … tape.
For the non-electric, purely mechanical version of this device, changing the hand is not as simple as it is with some other exit devices, for example, flipping the device over, but it is not all that hard to do.  Below are the directions for field handing excerpted from the 2200 Series installation instructions from the Stanley Precision web site.   Why they have arranged the steps to be followed in counterclockwise order is a mystery to me, but I am not here to judge, just inform.

At a glance you can see that there is some disassembly of the exit device head required to change the handing of the device. But when you add electrified trim control it complicates things a bit.

In the photo below you see the wires for the solenoid where they pass through the hole in the bracket.  That bracket is an integral part of the active head and it does not move.  However, the solenoid must be installed at the other end of the active head in order to interface with the working parts of the device and the wires are just long enough to allow it to be installed where it is.  There is no play in the wire that would allow the wire to remain where it is and yet allow one to move the solenoid.

 

 

 

In order to move the solenoid to the other side of the active head, one must either cut the wires (a nightmare, do not do it) or to completely disassemble the exit device, bar and all.

Why do you have to completely disassemble the exit device to pull the wire through?  Because it is taped to the baseplate of with a piece of filament tape that runs the length of the bar.  The tape must be removed to free the wire so you can pull it out through the hole in the bracket.

I could not find the directions for changing the hand of the E2203, but here is a drawing of the solenoid placement for the E2103 rim exit device taken from the installation instructions from the E2103 Kit.

 

 

Once you have pulled the wire through the hole, changed the hand of the head, taped the wire back down the length of the bar baseplate and reassembled the device, you’re done.

Below is a picture of the E2203 with handing freshly changed and the device reassembled and ready to install.

 





Like I said: order it fail safe or fail secure… AND ORDER IT HANDED.

 

locksnsafescom

Your source for quality security products with superior service!

Compatibility Issues

What’s wrong with this picture?

When specifying door hardware I understand that it can be like being an kid in a candy store.  But like that kid, you may not be able to always get everything you want.   Sometimes “this” might not go with “that.” There are some examples that should be obvious, such as fire rated exit devices with cylinder dogging, since fire rated exit devices must positively latch each time they close without exception and any kind of dogging could prevent that.  But other combinations of options are less obviously incompatible.

One elusive combination of exit device options that pops up sometimes is delayed egress with electric latch retraction.  In most electric exit devices this is almost a contradiction in terms because they use the same mechanism for delayed egress as they do for electric latch retraction, except it works the opposite way.  For example, the Von Duprin Chexit uses the same kind of motor that the Von Duprin EL devices use, except that the Chexit motor pushes out on the latch mechanism while the EL motor pulls in.  What would be necessary I guess would be to build a little transmission so one could shift gears from push to pull to switch from delayed egress to electric latch retraction and back again.

But since no one has yet invented this miniature transmission neither the Sargent Electroguard nor the Von Duprin Chexit currently offer both delayed egress and electric latch retraction in the same device.  The only device I have encountered so far that does offer these two options together in the same device is Detex.  There could be others.  Check with individual factories to be sure.

Two options that are offered together in many, but not all exit devices, with varying degrees of availability, are cylinder dogging and electric latch retraction.   For example, Sargent offers cylinder dogging with electric latch retraction, but only when factory installed.   Von Duprin offers “Special Dogging” (SD prefix) with electric latch retraction.  In this case the effect of cylinder dogging is accomplished by a cylinder operated latch holdback feature in the center case of the device.  (Not quite the same as traditional cylinder dogging.)  Precision can offer cylinder dogging and electric latch retraction in the same device without complication because their electric latch retraction and cylinder dogging mechanisms happen in different sections of the rail altogether.  Corbin and Yale offer devices with cylinder dogging and electric latch retraction in the same device.   Yes, the electric latch retraction and cylinder dogging combo is all over the charts when it comes to availability.

 





As in all facets of life, when in doubt, contact your friendly door hardware genius.

 

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Von Duprin QEL Kit Diversity

qelhdqel

QEL and HD-QEL modular conversion kits.

Von Duprin offers several versions of its QEL (Quiet Electric Latch retraction) conversion kits for its 33, 35, 98 and 99 series exit devices.  The variations are:

  • Modular (no baseplate)
  • Modular, with connectors (Molex)
  • Modular with hex dogging
  • Modular with hex dogging and connectors
  • With baseplate, specify 3-ft. or 4-ft.
  • With 3- or 4-ft. baseplate and connectors
  • With 3- or 4-ft. baseplate and hex dogging
  • With 3- or 4-ft. baseplate, hex dogging and connectors

None of the modular kits come with baseplates.  Kits with baseplates offer a small ease-of-installation advantage because replacing the whole baseplate is slightly faster than field installing the modular kit onto an existing baseplate.  Modular kits can be installed in either 3- or 4-ft. devices, so if you want to have one kit on your truck, a modular kit would be the logical choice.

Which modular kit should you get?  I would suggest the HD-QEL Modular Conversion Kit with Connectors.  If you don’t want hex dogging, you can use a blank cover plate or plug the dogging hole in the existing cover plate.  If you don’t want the connectors, you can cut them off.  And since at the time of this writing there is no price difference between a modular kit with connectors and/or hex dogging, or without connectors and/or hex dogging, you might as well get the one with all the bells and whistles.  As I indicated, you can always dial it back.

While Von Duprin recommends any of their PS900 series power supplies together with their 900-2RS relay board to run their QEL devices, many installers are using their own power supplies and this seems to be working just fine.   QEL draws a 1-amp inrush.  I recommend allowing 2 amps for each QEL on a power supply, and it is always good to isolate them on their own set of contacts in the power supply if possible, using a power distribution or relay board.   If these contacts can be protected by a fuses or circuit breakers, so much the better.   A regulated and filtered power supply is also a plus.





Unlike many power supplies, I am both unregulated and unfiltered … and I like it that way.

 

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Door Sag

Which door is sagging?

Which door is sagging?

I have mentioned this before, but it bears revisiting.  Lock problems and door problems are often related.  If the door is does not swing or is not hung properly the lock may not work properly either.

I bring this up now because I was recently called upon to go out and do actual work. I am no longer used to this and will usually refuse these opportunities, but my daughter called to say that the restaurant where she is working was having problems with their walk-in wine cooler. This small, chilled room is unfortunately located near the entrance of the restaurant, around the corner from virtually all activity except exiting and entering. Should an unscrupulous patron give the grade one cylindrical storeroom function lock a tug on their way out, the door would swing open, inviting pilferage of some very expensive vintages ranging in the hundreds of dollars. Some might even qualify as grand theft. So she asked if I would come out and have a look, and being the wonderful dad I am I grabbed my toolbox and cordless drill and headed out.

I managed not to hurt myself, so I am grateful.

When I arrived on the scene, I noticed immediately that the door was sagging – that is to say, it was no longer square within the door frame.  I could tell because – as in the handy picture I provided above – I could see that the gap between the header and the door was noticeably larger on the lock side than on the hinge side of the door.  I checked the top hinge screws – often the culprit in these situations – but all was well up there and all the screws were tight.   This could mean only one thing:  the door frame had settled with the building and was no longer square.  As a result the latch no longer lined up with the electric strike and the lock would no longer latch.

saghingeSince the door was wood I could have pulled the door, removed the hinges, planed the hinge edge and re-cut the top and middle hinge mortises to bring the lock edge up and back in line with the frame; or I could broken into the walls on both sides and adjusted the door frame so it would be square again.  But because I am old, tired, and was not getting paid I decided to take the easy way out:  I shimmed the bottom hinge, forcing the lock side of the door slightly up so that the lock would once again align with the electric strike.

To shim the bottom hinge I simply put a washer behind the hinge at the location shown in the picture  at right.  Then I explained to the restaurant manager that this was a temporary fix and that later on the door would most likely need attention again because the problem would probably recur.

So I left everyone happy and with a working door, but also with a warning.  Since the door frame is no longer square it is likely to continue in the same direction and someone (not me) will have to address it in the future.

 





And once again I looked like a … Hardware Genius.

Experiencing the New Von Duprin Chexit

Chexit door label from Chexit installation instructions.

Von Duprin Chexit door label from Chexit installation instructions.

Last year Von Duprin began shipping Chexit self-contained delayed egress exit devices that are motorized instead of solenoid driven.  Since they are motorized, the new Chexits draw less current and will probably be more reliable than the previous solenoid-driven version. This means a less serious, less expensive power supply, less need for high capacity, high gauge, high cost wire and greatly increased workable wire run distances – all good things.

The new Chexit will do everything the old Chexit did, including release of the outside lever trim when the external inhibit function is activated by access control or another external switch.  That remains a way to get access control out of a Chexit by simply adding a blank escutcheon or other unlocked outside trim to the Chexit exit device.

As of this writing Exit-only function Chexit devices were being shipped less the part number 040193-00 cable used to connect the E996L to the Chexit PC board.  The cables are only provided if you order the Chexit from the factory with trim, but that is okay as long as you want to use no trim or non-electric trim.  Electrified trim is a means to provide fail secure access control from the trim side, so if the fire alarm goes off and powers down the Chexit, the fail secure electrified trim will stay locked.  Entry can still be gained by key.

On another note, recently I was involved in an application where the installer was replacing a mortise exit device and wanted delayed egress from the push side and free ingress from the pull side.  Luckily it was a mortise device, so all I had to do was provide a Chexit mortise exit device with blank escutcheon (passage function) trim because THE MORTISE LOCK ACTS INDEPENDENTLY FROM THE CHEXIT ON THE TRIM SIDE. Cool. 🙂

Bear in mind that  the Chexit remains active while people are using the passage function trim to get in, so if they happen to depress the touch bar, say by bumping it up against the wall for two seconds, they may activate the Chexit alarm.   Von Duprin Tech Support suggested a palm switch on the trim side to activate the inhibit circuit in the Chexit while a person enters from that side.

 





It was fun, easy, and I looked like a … Hardware Genius.

Choosing a Delayed Egress System: Self-Contained, or Built from Components?

Delayed egress is a process that delays unauthorized exit from a space while complying with NFPA 101 life safety code.  Use of this process is strictly regulated with the help of building inspectors and fire marshals across the United Sates.  With that in mind it is always a good idea to get your local AHJ (Authority Having Jurisdiction) on board whenever you are planning to install delayed egress on an opening.

When you beginning planning your delayed egress system you will find that many systems on the market are self-contained.    These could be delayed egress electromagnetic locks or electrified delayed egress exit devices.

Here are some examples of self-contained delayed egress maglocks:

  • SDC 1511S
  • Schlage Electronics M490DE
  • Dynalock 3101C

Here are some examples of self-contained delayed egress exit devices:

  • Detex V40 EE
  • Von Duprin Chexit
  • Sargent Electroguard

delayed-egress-anatomy
Almost all delayed egress systems are made up of the same components:

  1. Delayed egress timer and relay logic board
  2. Initiating Switch (to initiate the delayed egress process)
  3. Audible alarm
  4. Signage
  5. Reset switch
  6. Optional bypass switch
  7. Fire Alarm interface
  8. Power supply
  9. Locking device

Therefore it is possible to construct a custom delayed egress system from components.  Later I’ll talk about why you might want to choose a built-from-components delayed egress system instead of a self-contained one.   The following sections describe each part of a built-from-components delayed egress system.

Delayed Egress Timer and Relay Logic Board

This board is UL Listed and specifically designed to perform all delayed egress functions in compliance with life safety code.   Here are some examples of component boards for delayed egress:

  • Securitron XDT-12 or XDT-24
  • Seco-Larm SA-025EQ

The board is the brains of the delayed egress operation.  It has contacts to wire in switches for delayed egress initiation, fire alarm interface and system reset, timers to control nuisance and egress delay, and relays to control locks and notify external devices.

There are also delayed egress controllers that offer more features.  The following may include the delayed egress timer/relay board and some other required feature(s) such as the initiation switch or the audible alarm.

  • Alarm Controls DE-1
  • Security Door Controls 101-DE
  • Securitron BA-XDT-12 or BA-XDT-24

Initiating Switch

The switch that initiates the delayed egress process shares several characteristics with any request-to-exit switch.  To comply with life safety regulations it must require no prior knowledge to operate; it must require no more than one motion to operate; and it must be placed in relation to the door according to life safety standards in your local jurisdiction.  I think that the best possible initiation device is a mechanical push bar with a switch, such as the Adams Rite 8099-M or the Securitron EMB.  In a panic situation it remains obvious that to get out, one must push on the bar, and because it is mechanical it is unaffected by power outage.  If it is wired to open the contact when pushed, if the wires leading to it are cut it will initiate the delayed egress process.

In rare circumstances where it might be permitted, the locking device might be a fail safe electrified mortise lock that is locked on both sides, inside and out.  Then the initiation switch might be a palm switch next to the door.

Audible Alarm

The mandatory audible alarm sounds for 15 seconds before the delayed egress controller releases the locking device to allow exit.  It’s loudness must be between 81 and 88 decibels.  In some jurisdictions the alarm must be manually reset at the door; in others it may be self resetting via timer or door position switch.  Yet another reason to have a heart-to-heart talk with your local AHJ when designing your delayed egress system.

Signage

The wording on the mandatory sign must comply with life safety code.  There are minor variations in wording.  I suggest buying a sign that is part of a delayed egress system.  The sign that comes standard with the Von Duprin Chexit is readily available as a separate part.

Reset Switch

As mentioned in the “Audible Alarm” section above, a delayed egress system reset switch located at the door is mandatory in some jurisdictions.  Check with your local AHJ.  In some jurisdictions delayed egress systems are allowed to be reset by remote switch or other means, such as a door position switch.

Any kind of momentary contact switch will do the reset switch job, but delayed egress system reset switches located at the door almost always require some kind of security to prevent unauthorized resetting.   Standalone keypads or key switches are often used for this purpose.  Delayed egress systems can also be integrated into existing access control.

Optional Bypass Switch

Not required but often needed, the optional bypass switch allows authorized personnel to exit without triggering the delayed egress system.  Again, any momentary contact switch will do, but usually some security is required.  If you are using a keypad as the system reset switch and the keypad has more than one relay, you can program the second relay to be the bypass switch.

If access from the exterior side is required a bypass switch is required on that side.  Sometimes security is not needed from the exterior side.  In that case a simple momentary contact pushbutton will do the job.

Fire Alarm Interface

The mandatory fire alarm interface allows enables fire alarm panel to deactivate the delayed egress system immediately in the event of a fire alarm.  This is an integral part of the life safety code that allows a delayed egress system to exist.  Therefore, if your building does not have a fire alarm panel, without special permission from the local AHJ you cannot have a delayed egress system.

Power Supply

All delayed egress systems I have had experience with run on low voltage power that comes from a low voltage power supply.  Generally delayed egress systems require regulated and filtered power at 12 or 24 volts.  Delayed egress controllers draw very little current, but as will all electrically operated systems, the current draw of all attached devices must be taken into account when selecting a power supply.

Locking Device

The locking device must be electrically locked and fail safe from the egress (interior) side.  The most frequently used locking device in a component based delayed egress system is the electromagnetic lock.

Why Build a Delayed Egress System?

Why would you put together a delayed egress system from components when there are so many good self-contained systems?

  1.  To Save Money.  Piecing together a delayed egress system can be significantly cheaper than buying a self contained delayed egress system.
  2.  To take advantage of existing hardware.  For example, if there is already an electromagnetic lock on the door, adding the other components is relatively easy.
  3. Conditions at the door prohibit use of a self contained delayed egress system.  For example, door size or the presence of existing hardware may require the installer to seek a more creative solution.

 





Bottom line, unless you have a prison, you cannot lock ’em in.  Well, not without permission.  🙂

Door Hardware Triage

The Medical Metaphor

medicalAs previously published in Doors and Hardware Magazine, Feb. 2016

As in the medical profession, correct diagnosis of door hardware problems is wholly dependent upon the knowledge, skill and powers of observation of the person whose job it is to correct the problem.  “The devil is in the details,” they say, and it is never truer than when said in reference to doors and hardware.

Another old saying, “ignorance is bliss,” can be liberally applied to who those innocent building occupants and visitors who think that the answer to a lock that is not latching is to slam it until it does – or until the hardware falls off, whichever comes first.  Yet by the same token, door hardware technicians who fail to look at door hardware problems holistically are equally blissful.  If you have ever seen the latch hole in an ANSI strike enlarged to include half the head of the bottom mounting screw in order to remedy what is clearly a hinge problem you will understand what I am talking about.

The above occurs because the technician sent to solve the problem is guilty of treating the symptoms while failing to diagnose the disease.  He or she observes that the latch is making contact with the strike too low to drop into the strike hole as it should, but does not question why this is happening.  This example is a simple one, but the principle applies to more complex problems as well.

Method

A great way to make sure you correctly identify a door hardware problem on the first visit is to have a consistent method of examining the total opening.   An example follows:

  1. If possible, speak with the person who has reported the problem, or better yet, meet with them at the opening so that they can show you what the problem is.
  2. As you approach the door, visually check the gap around the edges of the door on the top and both sides.  (The gap should be one-eighth inch.)  If the gap is greater in one place and less in another, the problem may be a bent hinge or misaligned frame.
    Open the door.  How does it feel?  Does the door itself stick?  If it has a latch, is there resistance when you turn the lever to retract it?  Do the hinges groan or squeak?
  3. Inspect the door for dents and abrasions.  For example, scratches at the top of the lock-side edge may indicate bent or loose hinges.   Dents may indicate attempted forced entry:  check for damage to internal lock parts.  A dent in the gap between the door and frame above the top hinge may mean an object was placed there.  The frame may be damaged and/or the top hinge may be bent.
  4. Inspect the hardware for damage, missing parts and/or wear.   If it is a hollow metal frame, are the silencers installed?  If there are no silencers the door will not align properly and the lock will not latch correctly.  Is the door closer leaking?  Does the door closer arm move smoothly?  Are the hinge screws all present and accounted for, and are they tight?  If there is a latch, there probably is a drag mark on the strike.  Does the drag mark reflect correct alignment?

In other words, look at the door, the frame and the hardware thoroughly and completely, and always do it the same way.  That way you won’t fix one problem just to return the following week to fix another problem that you missed.strike

Tools May Be Required

To identify a door hardware problem you may find it helpful to use instruments or tools.   For example, a carpenter’s level can help you determine whether a door or frame is level or plumb quickly and accurately, and a carpenter’s square can show immediately if the frame is true or sprung.   A tape measure may be helpful to check if hardware is correctly located, whether or not the gap between door and frame is consistently one-eighth inch, and if one leg of the door frame seems to be longer than the other.

One problem most swiftly identified using a carpenter’s level is positive pressure.   If you detach the closer arm and tape back the latch on a door that is level, and it swings open seemingly of its own accord, chances are it’s a positive pressure issue.  Positive pressure occurs when the air pressure inside the HVAC ducts is greater than the pressure outside, causing air to be constantly forced out of the structure.  Positive pressure can be powerful enough to prevent a door closer from closing the door, and sometimes the only cure is when the HVAC technician changes the settings on the air circulation system.

The positive pressure issue is one of those door hardware issues that may require someone besides a door hardware technician to fix.

Waiting For The Electrician

Problems with electro-mechanical and electronic locking systems, like positive pressure issues, may require a low voltage or electronics specialist to solve in addition to a door hardware technician.  For liability reasons it is important to use technicians who are appropriately licensed as required in your locality.

Often these problems are due to mechanical as well as – or even instead of – electrical or electronic issues.  Therefore the best situation for electronic or electrical door hardware triage is when the technician called upon to fix a problem is skilled in all three disciplines. Out in the world we are finding locksmiths that have their low voltage electrical technician license and a working knowledge of how to troubleshoot or program an access control system, systems integrators who can disassemble and repair a mortise lock, and even electricians who can adjust a door closer or repair an exit device.

This is a phenomenon driven by a market that desires to have one technician who can do everything, both for convenience and economics.  In any event, a technician equally skilled in these areas solves the problem of cross discipline communication.  If you’ve ever had to explain the difference between fail safe and continuous duty electrified door hardware to someone who just does not get these concepts you will understand what I’m talking about.

For this reason alone it behooves one in the door hardware repair and installation business to learn as much as they can and get all the credentials they need to be able to service all the door hardware out there in today’s electric and electronic world.

Closure

The age of door hardware in which we work today is the age of the renaissance woman or  man, student of many skills.  However, diagnosing the often complex ailments of doors and door hardware takes more than skill and knowledge:  it requires mindfulness, openness, resourcefulness and humility.  It is not only necessary to know what could go wrong (and doubtless will, according to Murphy’s Law); it is necessary to be aware enough to observe all the symptoms, to be open to all possibilities and to be imaginative in creating solutions.  One must also have the humility to realize that it is not possible for anyone to know absolutely everything.  Sometimes the most useful tool at your disposal is your mobile phone.  A call to factory tech support can often save hours of fruitless aggravation.

 





No man is an island – but some men belong on one. 

The Pressure’s On

balloonPositive Pressure Issues

Sometimes doors are required to perform conflicting functions simultaneously.  For example, in order to comply with the American Disabilities Act a particular door may be restricted to a door closer that requires as little as five pounds of opening force.  This same door may be required to lock automatically without fail.

One solution could be to use a non-hydraulic, motorized power operator (automatic door opener) instead of a standard hydraulic closer.  Since many non-hydraulic power operators do not depend on a spring for closing force it is possible for them to have an ADA compliant opening force and also exert a closing adequate to close and latch the door.  Most power operators that fit this description must be installed by AAADM certified installers.

Without the magic fix of the non-hydraulic power operator, all a door technician can do is fine tune the door so that it swings perfectly and is perfectly balanced; fine tune the locks, hinges and door closer to peak performance under the opening force restriction; and pray there isn’t a positive pressure or wind issue.

One caveat:  deprived of electricity, a non-hydraulic power operator will neither open nor close the door.

Positive pressure HVAC operation is a prime example of how the intended function of a door can be impeded or prevented by the normal operation of building infrastructure.   Positive pressure in a building is accomplished by using the HVAC system to add air from outside the building to the air that is already in the building.  As with a balloon, the added air pushes outwards in all directions.  When an exterior door is opened, air flows out through the open portal, acting as an invisible barrier that keeps outside air out.

Unfortunately positive pressure acts like a constant wind pushing on the inside of the exterior doors.   Since almost all exterior doors swing out, the net effect of positive pressure HVAC on exterior doors is that of blowing to doors open and/or preventing them from closing.

The non-hydraulic power operator idea discussed above can usually solve the problem, but I have had some success adjusting door closers to compensate for positive pressure situations.  I have found that a slow swinging speed followed by a fast latching speed will often accomplish the mission.  This solution, however, can create other problems such as creating a wider time window for unauthorized persons to enter while the door is still shutting, for example.

I have found no reliable fix for an opening subjected to positive pressure that must comply with ADA reduced opening force requirements; however, since positive pressure on out-swinging doors inherently reduces opening force, there is some hope.

In the best of all worlds, door hardware technicians and HVAC technicians work together to coordinate positive pressure ventilation needs with security and ADA compliance requirements.

Excerpt from Tom’s article “Butcher, Baker, Door Hardware Technician… ” published in the February 2015 issue of Doors and Hardware Magazine, magazine of the Door Hardware Institute.


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