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Quest for the 24-Inch Exit Device with Electric Latch Retraction

Yale7100I had a lot of fun recently trying to meet a customer’s requirement for a 4-foot by 7-foot pair of doors in a hospital that needed to be fire rated and automated.   I found that Corbin and Yale (sister companies whose exit devices are almost identical) offer fire rated surface vertical rod exit devices with electric latch retraction that meet this need.   The installer will be able to put some kind of little power operator on each 24-inch leaf of this four foot pair and cram two fire rated surface vertical rod devices onto these same narrow leaves.  Doubtless it will look odd, but it will work.

Admittedly the whole idea is a bit dubious.  True, by having both leaves opened simultaneously by power operators will provide amply more than the minimum 32-inch clearance demanded by the American Disabilities act, but if anyone manually opens either leaf it certainly will not.

Sargent and Von Duprin offer 24-inch fire rated exit devices, but neither offer them with electric latch retraction.   It is unfortunately necessary to call these companies’ tech support lines in order to verify this information, since their price lists both show 24-inch possibilities without disclaiming the electric latch retraction option.  Neither the Sargent nor the Von Duprin has a note to say the 24-inch device is not available with electric latch retraction that I could see; if that is in fact the case, the buyer is left to beware the exit device order that bounces back because it was ordered with options that are mutually incompatible.

It’s good advice anyway to always call the manufacturer’s tech support whenever there is a question.  Waiting on hold is a lot better than storing thousand-dollar exit devices that didn’t work out on the job.

Note:  A reader named Rick writes in with this about Sargent electric latch retraction:  “Tom, I just stumbled across your site this evening, while doing a search for Fail Secure mag locks of all things (IR says there is one).  But I saw your latest article on latch retraction units and had to clarify the Sargent restrictions. These can be found within the catalog pages, specifically the page showing the 56 option (toward the back). It says:

              -Wide Stile Door 28″
              – Narrow Stile Door 26″
Thank you, Rick, for this bit of info.  I should add that it is always good to check all the literature at your disposal for any information you are looking for.  Some manufacturers have more detail in their price list than in their catalog, and others vice versa.  Thanks again.

Securitron’s new PowerJump ICPT™ Inductive Coupling Power Transfer

Securitron’s new PowerJump ICPT™

Securitron’s new PowerJump ICPT™

The door hardware industry breathlessly awaits the debut of Securitron’s new PowerJump ICPT™ Inductive Coupling Power Transfer.  The PowerJump is Securitron’s miraculous new device that may put a significant dent in the electric through-wire hinge market.  I mean, why would you drill a half inch hole the width of a 36-inch door when you could install this little pair of black boxes on the lock side?

I downloaded the installation instructions from the Securitron web site to check out product attributes and characteristics.  The first thing I noticed, having spent much of my career working with wooden doors, that the Securitron PowerJump ICPT is a bit friendlier to a hollow metal door or frame install than it is to a wood door or frame install.  Because the body of the unit is almost the same size as the face, the installer must take great care to cut a very clean hole for the body so that the hole does not exceed the size of the face.  This can be a little tricky when using a speed bore bit (or auger bit as mentioned in the instructions) to drill the two deep holes for the mortise pocket before cutting in the face.

One trick I have used to use when installing mortise locks was to cut in the face first and get that nice and clean before drilling the holes.  I had good success with this because it gave me a very clear outline to stay within – much like coloring inside the lines with crayons in kindergarten.  Installing the PowerJump is a lot like installing a really small mortise lock, actually.  The face is the same width and a standard architectural grade mortise lock – 1-1/4 inches.

The PowerJump ICPT draws 500mA at 24 volts DC on the frame side, will transmit it across up to 3/16 inch of empty air and output either 250mA at 24VDC or 500mA at 12VDC on the door side.  500mA seems a little slim to be powering an electrified mortise lock.  Usually I like to see a bit of a cushion when it comes to current, so I would usually not power a device that requires 250mA at 24 volts DC, like a Sargent electrified mortise lock, with a power source that provided no more than the 250mA required.  I’d be a lot happier with a power source that has a capacity at least 1.5 times as great as the appliance being powered.

However, the average electrified hinge with 28-gauge through-wires only has a current rating of about 160mA and we have been powering electric mortise locks with these for decades.  Since I am not an electrical engineer I am not sure how that works, but it does.  I am also mystified by the science behind transmission of electrical current by induction.  Therefore, like most installers, I trust Securitron to produce yet another innovative product that works well.   I’ll be waiting to hear how installers like it when it is finally released.  I know I’ll hear about it one way or another.

The Double Door Rim Strike – A.K.A. “The Pocket Ripper”

pocketripperOne of the hallmarks of bad hardware choices is the “pocket ripper” strike, used on a pair of doors when there is an inactive leaf with flush bolts or a vertical rod exit device and an active leaf with a rim exit device. Whenever I see this I think, “Cheap bastard,” because the only reason for this half fast solution is money and the desire not to spend it on doing the job right.

This lovely piece of hardware earned the nickname, “pocket ripper,” but hanging into the opening at a convenient height to catch the front pocket of a pair of trousers, resulting in egregious damage to said pocket and colorful language on the part of the victim.

What is the right way to secure a pair of doors? Vertical rod exit devices are the best. My second choice would be a mortise exit device with an open back strike and a vertical rod exit device on the inactive leaf. My third choice would be a mortise exit device with flush bolts on the inactive leaf.

Below are a couple of examples of the ‘pocket ripper.’   On the left is the classic Von Duprin 1609 strike and on the right an example from Ingersoll Rand in Europe.  The European version looks like it has better manners.

In the center we have the Hager 4921 strike that really looks like it could take out more than just a pocket if you catch it the wrong way.





In addition, I find that often the rim latch stops dead before latching on the strike.  Also, depending on how you install the rim device, the latch may drag across the edge of the other leaf, scraping an ugly divot over time.  Yes, all in all a hardware choice to be avoided if you can.


Securitech Trident Multi-Point Deadbolt Exit Lock

Trident 4-point deadlocking exit device.

Simple and robust design helps to ensure security and longevity; single motion egress ensures life safety code compliance.  

Simple to order and to install, the Trident offers excellent security while preserving life safety.

The first thing I noticed when I unpacked the box was the small number of parts.  The second thing I noticed was how well all of these parts are labelled.  As I read the installation instructions I was struck by how easy Securitech had made the installation process, especially with the inclusion of a metal template to help get everything lined up just right.

I assume that the Trident is named for the three active bolts that secure the door on the lock side, but with the inclusion of the passive hinge side bolt it is actually a four point lock.  The hinge side bolt slides passively into its keeper whenever the door is closed.

Trident is a heavy device, so before installing it, make sure your door swings and closes properly and the hinges are in good shape.  I suggest using hinges with non-removeable pins so as not to rely solely upon the Trident’s hinge side bolt.  A stainless steel continuous hinge would be even better for both security and durability, if it is possible to use one.

Every locking mechanism of the Trident is through-bolted through pry-resistant steel plates, so casual attack using a pry bar would likely be fruitless no matter how much time the would-be burglar might have.  Each locking bolt is substantial and housed in a very sturdy mechanism.  Bending one of them would be difficult; bending all of them enough to gain entry would be almost impossible.  The main outside plate is impressive-looking with its Securitech logo and satin stainless steel finish, and since it is through-bolted to the head of the device in several

Photo by Tom Rubenoff

places, it’s pretty strong, too.

The weakest part of any muli-point locking device is the door frame.  Fully grouted (concrete filled) hollow metal frames hold up the best under attack.  At the very least, to have real security measures must be taken to ensure that the door frame cannot be either pulled out of the wall or bent away from the locking bolts.

To maximize security, I suggest not using the optional exterior key control with this device.  The presence of a key cylinder outside provides a target for burglars.

The Trident comes standard with a paddle that tells the user to push to exit and alarm will sound, but since the alarm is optional, this may be an empty threat.  Be sure to order your Trident with an alarm if you want one.

I was impressed with the workmanship evident in how the Trident is put together.  Everything worked super-smoothly and fit together perfectly.  The strong, simple design looks like it will provide many years of flawless service.  I highly recommend it for the back doors of stores, warehouses or factories or anywhere where a higher level of security may be needed.

Securitech Lexi Electrified Exit Device Trim

Great Problem Solver

The Securitech Lexi series retrofit exit device trim is available with a variety of back plates and adapters that allow it to be used with most major brands, including many surface vertical rod and concealed vertical rod exit devices.  Compatibility with a variety of vertical rod devices is a major plus.

I mean, anybody can electrify a rim exit device by simply installing an electric strike.  However, while it is possible to install an electric strike on a vertical rod device it rarely brings a good result.  First of all, in order to use an electric strike you have to first lose the bottom rod.  That just leaves one latch at the top of the door to provide all the security.  If it is a tall door or a flexible door – like an aluminum storefront door – you can pull the bottom open several inches with just that top latch holding it.  Add a little time and a little hinge sag and pretty soon you have no security at all.

The other solution is electric latch retraction, or electric latch pullback, as some manufacturers call it:  relatively expensive compared with a Lexi trim.  Also, electric latch retraction is a fail secure only solution when locking trim is used and therefore may be inapplicable to fail safe installs such as stairwells, unless passage function (always unlocked) trims are used.

I notice that right out of the box the Lexi is very self contained.  Other than a tiny box containing mounting screws, tailpiece operators, and a cylinder collar and cam, what you see is pretty much what you get.  It’s pretty hefty for its size – it is designed on the slim side so as to be usable on narrow stile as well as hollow metal or wood doors.   This does mean that the installer may have to be a little creative when replacing a larger exit device trim with the Lexi.

Installation instructions are easy to follow and short – only four pages, including the template. Something I would have liked to see in the instructions, but didn’t, was current draw.  If I am installing one of these, the number of amps it draws are not going to matter much to me.  But if I am installing twenty of them and want a centralized power source, now it’s an issue.  Yet it isn’t anything that an experienced low voltage specialist with a ammeter can’t find out in two seconds.

One of the great innovations I noticed right away is the rotation restriction clip that allows the installer to customize tailpiece rotation to the exit device.  I do not think that this is handled better by any other manufacturer.  Correct degree of rotation often determines whether a trim will work or not, and to have a trim that has degree of rotation so easily selectable is damn nice.

As mentioned in the sales literature, since Securitech’s Lexi trim is compatible with so many exit devices, if you have a facility with different brands of exit devices dispersed throughout, you can install access control and unify the exterior appearance at the same time.  And in addition to being versatile it is also durable.  Forcing the lever only causes its internal clutch to break away, and it can easily be set right by rotating it back the other way.

All in all the Securitech Lexi trim seems to be a well built, versatile problem solver.  I think you’ll find it useful in many access control installations.

The Keyway: Gateway to the Cylinder

The keyway is the shape of the keyhole of the lock cylinder into which the user inserts the key.  The keyway is designed to allow only keys of the correct shape to be inserted such that, when properly made, they will align the pin tumblers properly and operate the cylinder.  If you view a key from the tip, you can see how the shape of the key corresponds to the shape of the keyway.






The theory behind the keyway is to let only certain kinds of keys in and keep all others out, and keyways do this with varying amounts of success.  A variation on this idea is the “sectional” keyway system in which keys of slightly different keyways are allowed to “pass” into the cylinder keyway.  See the diagram of the Schlage hierarchy of keyways below:

The keyways shown at the bottom of the chart are designed to fit in only one keyway.  Unlike the keyways shown in the top two rows, actual locks have the keyways in the bottom row.  The keyways shown in the second row could be called sub-master sectional keyways because keys cut on blanks of these keyways will each pass several of the keyways in the bottom row.  Keys cut on the “L” keyway shown at the top of the chart will pass all of the keyways below it.  This keyway is designed to be used only at the level of Master or Grand Master key.

Unfortunately, some key duplicators use the “L” keyway key blanks to cut keys of any sectional keyway they may currently not have in stock.  This shoddy practice degrades the security of a master key section that depends on sectional keyways for security.

Restricted Key or Restricted Keyway?

Keys can be stamped with the words, “Do Not Duplicate” or “Property of [insert name of institution or government agency here],” and that may stop some honest people from getting the key copied.  The term, “restricted key,” however, usually means factory restricted keyway, and a factory restricted keyway can effectively inhibit unauthorized key duplication.

How Does a Factory Control a Keyway?

The most effective way to control unauthorized key duplication is to make the key blanks as difficult to get as possible.  Key blanks are like blank paper to a copier.  Imagine copy paper protected by a patent owned by a paper mill.  The only place to get the paper would be the paper mill.  Thus, one of the ways security hardware manufacturers protect a keyway is to protect it by patent law.  Part of that protection is aggressively pursuing anyone who violates the patent with lawsuits and other legal instruments to prevent patent infringement.

Another way factories protect keyways is to keep records of who is using what keyway and where.  Many companies have restricted key programs – Schlage Primus, Kaba Peaks and Medeco are a few examples.  Factories may keep signatures of end users on file.  In this case, requests for restricted products must be accompanied by a document that is signed with the correct signature or the factory will not release the product.

Some restricted keys come with an ID card that authorizes the card holder to get keys made.  This is less secure than key duplication that is controlled at the factory, but it is a step up from keys that anyone can get made at Home Depot.

Keyways and Key Bumping

In order to use a bump key to open a lock, the key bumper needs to have the right blank.  You cannot bump a cylinder with a bump key that has the wrong keyway.  It won’t go in.  Therefore, having a lock that has a somewhat rare keyway is a very easy and inexpensive way to make unauthorized entry by key bumping difficult.  Most of the people out there bumping locks open are not the brightest bulbs in the lighting fixture.  Challenge them with a hard-to-identify keyway and they will most likely be defeated.

Multi-function Doorways, Part Two

Secured stairwell doors are among the most basic multi-function door applications.  In most jurisdictions they must (usually)* be both unlocked and positively latched in the event of a fire.  Unlocked so that if a person, fleeing into the stairwell during a fire, finds the stairwell full of smoke, they can safely exit the stairwell.  Positively latched so that the door will remain latched closed against the spread of the fire.

Until there is a need for access control, a passage function mortise lock, cylindrical lock with UL listed latch or exit device with passage function trim are fine.  The application begins to get interesting when the need arises to lock a stairwell door.

Right up front, electric strikes are out of the question because of the unlocked/positive latching requirement mentioned above.   It is not possible to positively latch a door when the electric strike is unlocked.  There is no such thing as a fire rated, fail safe electric strike.  If you configure a fire rated electric strike to be fail safe it voids the fire rating.

Since electric strikes are unusable for this application, that leaves either electric locks or electromagnetic locks.  Both have advantages and disadvantages.  Fail safe electric locks positively latch whereas mag locks allow the installer to us the existing hardware on the door to accomplish positive latching.  Electric locks require running wire through the door and some means of getting the wire from the frame into the door, such as an electric through-wire hinge.  Not all inspectors like electromagnetic locks, so before you install them be sure to check with your local Authority Having Jurisdiction (AHJ ) – that is, Fire Marshal or Building Inspector.

If the stairwell door already has a fire rated exit device installed, there is probably a fail safe electrified trim available for it.  Once again, this means an electric through-wire hinge or other power transfer device would be required.  Sometimes existing exit devices are incompatible with the electrified trims available for that brand and model of device.  If that is the case, the exit device might have to be replaced with one that is compatible with electrified trim.

Alternatively, there are after market request to exit (a.k.a. RX) switches available for most exit devices.  One could be used to release an electromagnetic lock on the stairwell door.

Usually it is required that all electric locking devices on stairwell doors be controlled by the fire alarm panel.  When the fire alarm is in a state of alarm, it unlocks all the stairwell doors.  Two conductor wire is run from the fire alarm panel contacts to a special fire alarm relay in the power supply that powers the electric locks on the stairwell doors.  The alarm panel opens the circuit, causing the state of the fire alarm relay to change, thus powering down the fail safe locks and thereby leaving them unlocked.

An important detail:  technically speaking, according to most building and life safety codes, fire rated doors can only be modified in a fire rated shop.  Therefore if you field cut a raceway for an electric wire through the cross members of the door, for example, you are probably voiding the fire rating.  I have never heard of anyone being called on this, but it is good to keep in mind.  Just like it is good to keep in mind that the AHJ has total authority over what you can or can’t install.  Best make sure you’re on the same page with her or him, otherwise they do have the power to make you remove what you installed and replace both door and frame to repair the damage.

Happy hardware and good luck to you.

*Some jurisdictions specify that not all stairwell doors need be unlocked in the event of a fire, only certain doors.  For example, I have known some places where code was the door had to be unlocked at every fourth floor.  Check with your local AHD to find out what the rules are for your location.

Hot Stuff: Continuous Duty Electric Locking Devices

The Ohm Symbol

I regularly hear complaints about electric strikes, cylindrical locks or mortise locks that are hot to the touch.   When I ask, I am always answered that, yes, the device is being used in a continuous duty application.

Continuous duty means that the electric lock or strike is powered continuously, usually for several hours a day.  Most fail safe locks and strikes are run continuously, since they are usually locked part of the day and they require electric power to lock.  Whenever a door is kept unlocked by using an electrical timer, the lock or strike that is controlled by the time is run continuously for part of the timing cycle.

Heat in an electric lock or strike is caused by resistance in the electrical circuit as it passes through the coil of the solenoid inside the device.  Often this heat is sufficient to “burn out” the solenoid.   The solenoid does not actually catch fire, usually.  The term, “burned out” refers to a solenoid that has been ruined by excessive heat so that it no longer functions.

Heat from electrical resistance is exacerbated when there are problems with the supply of power.  For example, if the power supply provides less than sufficient amperage to constantly power the solenoid, the solenoid will ‘run’ hotter.  Similarly if there is a current drop because of a long wire run with inadequate wire gauge, the solenoid will not get sufficient current and will run hot.  Also if the voltage supplied is significantly higher than the solenoid is rated to accept, that could create a heat problem as well.

Often, however, there is no detectable reason for the solenoid to run hot.  Sometimes, it seems, they just do.

A great way to mitigate the problem of the hot lock or strike (when all power supply problems have been solved) is to use an electrical device in line with the electric lock or strike that provides it with a full inrush voltage and current upon activation and then reduces the voltage and/or current to a holding level, allowing the solenoid to run cooler.

Several companies offer these units.  Here are some examples:

  • HES:  Model 2005M3 Smart Pack controller
  • COMMAND ACCESS:  CRU-2 current reduction unit
  • TRINE:  LC-100 line conditioner



Full Height Housings for Electromagnetic Locks

Maglocks are generally great problems solvers, but they also create problems.  One significant problem is the fact that they are usually installed on the header, and therefore only lock the top of the door.  If the only lock on the door is a magnetic lock and the door is fairly flexible, a reasonably strong person may be able to pull the bottom of the door open four or more inches.

One solution to this problem is to install mags top and bottom on the lock side leg of the frame rather than on the header.  If you have an opening that measures at least 35 inches from stop to stop and you use magnets that are three inches wide or less, you can install mags in the opening and still have 32 inches clear to comply with the American Disabilities Act.  The problem with this idea is that no matter where they are installed in the opening, users are likely to bump into them with some body part or other.

Enter the full height housing for electromagnetic locks, an enclosure that houses one or two maglocks and mounts on the stop of the lock side leg of the door jamb as illustrated below.

The illustration above is one I prepared for a customer so that I could order a custom built, full height housing for two electromagnetic locks.  The drawing shows the dimensions I requested as indicated by the lines with arrows at both ends:  height of the opening from threshold to header stop; distance from header stop to center line of upper maglock prep; distance from threshold to center line of lower mag prep; and distance between the center lines of the mag preps.

Provided the opening is at least 35 inches clear and the housing is no more than three inches wide, the opening will still comply with ADA after the full height housing system is installed.


Multi-function Doorways, Part One

As seen in Doors and Hardware Magazine.

Whenever something is invented, humans find more uses for it.  This is certainly true for door automation and electric locking.  It was not long after people realized a door could be unlocked remotely using an electric strike and a door could be opened automatically using a power operator (automatic door opener) that they began using these devices together.   Of course this combination of devices was soon interfaced with intercoms.  Exit devices with electric latch retraction and electromagnetic locks were thrown into the mix, as well as access control, delayed egress and/or security interlock systems.  Any of these systems alone is sufficient to complicate an installation, but when you start to use several on one opening, that’s when things really start to get interesting.

A hospital can be one of the best places to run into a doorway that needs to perform many functions (pun intended).  Hospitals seem to have more varied reasons to keep different people out at different times, or to let them in or out by different means.  In addition to standard life safety and security issues, hospitals also have to anticipate the needs of patients who may be under the influence of medication and/or mental disorders and/or have physical limitations.  Some patients must be kept inside for their own safety while all patients must be able to exit swiftly and safely in the event of a fire.

Let’s use as an example a hospital emergency ward entrance used primarily by ambulance drivers.  The hospital wants only ambulance personnel and the security guard  to be able to activate the power operator, and to control access by use of a remote switch operated by the security guard  for the general public and an access code by hospital employees (other than ambulance personnel).

Since it is a pair of doors, concealed vertical rod exit devices are the most efficient, safe and secure way to lock them and provide reliable free egress in the event of an emergency.  However, since there is a power operator involved, these devices must be equipped with electric latch retraction; and since use of the power operator was to be limited, a second electric means of opening the door would be required.

A simple way to solve the problem of the second means of unlocking is by using electrified exit device lever trim with one of the concealed vertical rod exit devices.  Persons not requiring the power operator can get in by using the access control, or the security guard  can “buzz” them in using one of two remote buttons.  Because there will be two means of unlocking the door electrically, the security guard  will need a small desk unit with two buttons:  one that activates the power operator and electric latch retraction and one that activates the electric exit device trim.

Below is an amateur wiring diagram (made by me) of how, basically, the system works.

Central to the concept is an access control device with two relays and a request to exit input.  This allows several of the connections to be made through the access control system.  If the access control system on site does not provide more than one relay, the same functions can be accomplished by using additional relays in the power supply.

The system as shown in my illustration above works like this:

Ambulance personnel activate the power operator using the access control system.  The access control system signals the power operator via contact closure in Relay #1.  The power operator triggers the relay in the power supply to retract the latches of the exit devices, then opens the door.

Other authorized hospital personnel use the access control system to unlock the lever trim.  The access control system changes the state of Relay #2, triggering the relay in the power supply to unlock the trim.  They turn the lever, pull the door open and walk in.

Injured people arrive on foot at the Emergency Room entrance.  The Security Guard sees them (or is notified by intercom, not shown) and lets them in by pressing the red button, activating the power operator, or by pressing the green button that unlocks the exit device trim.

There exist many possible variations of this system.  Knowledge of access control systems and door hardware are required, but the most important principal in play is the use of contact closure to signal multiple devices.