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Exit Devices with Electric Latch Retraction

Overview

Almost all exit device manufacturers offer the option of electric latch retraction on their touchbar-style exit devices.  Different manufactures may call it by other names such as ‘latch pull-back’ or ‘remote dogging’.  Some people refer a device with electric latch retraction as an ‘electrified exit device’, but that could also refer to electric unlocking of outside trim – a different animal altogether.  Electric latch retraction is accomplished by unsing a powerful solenoid or electric motor to actually retract the latch or latches of an exit device.

The advantages of electric latch retraction over other means of electrically unlocking exit device-equipped openings are:

  • Electric latch retraction is fail secure.  When power is supplied, the latches retract.  When power is shut off, the latches extend, securing the door.
  • Electric latch retraction works well with power operators because when the latches are retracted, the doors can swing free.
  • With electric latch retraction, pairs of doors continue to be latched top and bottom.

Cheaper alternatives, such as using an electromagnetic lock or an electric strike, would result in double doors that are only locked at the top.  If they happen to be aluminum narrow stile doors locked only at the top, a person could actually pull the bottom of the locked door open several inches with very little effort.  Such installations are at best sloppy, at worst not secure.

    Following are examples of electric latch retraction devices by different manufacturers.

    Adams Rite

    Division of Assa Abloy.

    http://www.adamsrite.com/

    Adams Rite makes hardware primarily for aluminum-and-glass storefront type doors, but also for standard hollow metal and wood doors. All of their exit devices are available with latch retraction.

    Their rim devices, the 3700, 8700 and 8800 series require no specific power supply. 12VDC models draw 1.5 amps, 24VDC models draw 600mA.

    All other devices draw an inrush current of 16 amps and require the Adams Rite PS-LR power supply. The PS-LR will power up to 2 Adams Rite exit devices with electric latch retraction.

    They make rim, concealed vertical rod, surface vertical rod, and mortise exit devices.

    They do not offer a retrofit kit for field conversion of existing devices to my knowledge.

    Doromatic

    Division of Ingersoll Rand.

    http://exits.doromatic.com/

    Doromatic makes exit devices primarily for aluminum storefront doors. All of their touchbar-style devices are available with electric latch retraction. Since purchased by Ingersoll Rand they use the Von Duprin type solendoid for latch retraction, and use the Von Duprin PS873-2 power supply to handle the 16-amp inrush current these solenoids draw.

    The PS914-2RS  will power up to 2 exit devices with electric latch retraction.

    Doromatic offers an electric latch retraction field retrofit kit for their 1490 series concealed vertical rod device and their 1590 series rim device. The EL1690 concealed vertical rod device and EL1790 rim device are in fact field retrofit kits to electrify the 1990 and 2090 series crash bar “pipe-type” exit devices for latch retraction.

    Precision

    Division of Stanley.

    http://www.precisionhardware.com/

    Precision makes exit devices for hollow metal, aluminum storefront, and wood doors, fire rated and non fire rated. All touchbar-style exit devices are available with electric latch retraction. ELR devices require an ELR150 series power supply. Use:

    • ELR151 for 1 ELR exit device
    • ELR152 for 2 exit devices
    • ELR153 for 3 exit devices
    • ELR154 for 4 exit devices

    Precision offers ELRK and NELRK series conversion kits to retrofit existing exit devices to electric latch retraction in the field.

    Sargent

    Division of Assa Abloy.

    http://www.sargentlock.com/

    Sargent offers a very wide variety of exit devices in various functions and configurations to accomodate diverse applications. All 80-series models are available with “Remote Dogging / Latch Retraction”. Sargent recommends the Securitron BPS-24-1 power supply, a simple 1-amp, 24VDC power supply, to power it electric latch retraction offerings.

    Sargent offers a retrofit kit to convert existing Sargent exit devices to electric latch retraction in the field.

    Von Duprin

    Division of Ingersoll Rand.

    http://www.vonduprin.com/

    Von Duprin offers electric latch retraction in rim, surface vertical rod, concealed vertical rod, mortise, and three-point exit devices for narrow stile aluminum storefront, standard hollow metal, and wood door applications. These would be the 33, 35, 98 and 99 series. Like the Doromatic exit devices discussed earlier, since they use almost exactly the same solenoid, Von Duprin electric latch retraction devices draw a 16-amp inrush current and therefore require the PS914-2RS to power 1 or 2 devices.

    Von Duprin offers retrofit kits to field convert existing exit devices to electric latch retraction.

    Global Considerations

    • Check door width. Electric latch retraction devices may not fit if the door is too narrow.
    • A means of getting current from the door frame into the device, such as a door cord or electric power transfer will be needed.
    • Voltage drop due to length of wire run could be an issue with high current inrush devices.

    If you have further questions, don’t hesitate to contact me at tomr@rubecom.us

    Easy Hinge Replacement

    The easy way to replace worn hinges is to leave the door on its hinges while you replace them.

    To do this:

    • You must replace the existing hinges with hinges of the same size
    • On a hollow metal door your hinges must match the hinge prep screw pattern
    • You must be able to open the door far enough so that you can reach the screws on the door leaf of the hinge with your screwdriver – typically you would need to open the door to about 100 degrees of opening

    If any of these is not the case, stop right here and go get some help.   You will need to take down the door, put it in a door stand and replace the hinges one leaf at a time, the old fashioned way.

    You will need:

    • A screwdriver that fits your hinge screws, most likely a number 3 Phillips head
    • A ladder
    • A piece of 1 x 4 pine between 2 and 3 feet long or similar piece of wood
    • Wood shim stock

    If you are replacing hinges with the same size hinges and can open the door wide enough, go ahead and open the door to the degree of opening that best allows you to access all the hinges screws on both leaves.  Beneath the door place the piece of pine, and then between the pine and the bottom of the door stack shim stock until the door is fully supported by the wood.  If there is a closer on the door, the door should be resting securely enough on the wood shims so that the closer cannot close the door.  However, the door should be shimmed just enough to take the tension off the hinges – no more.  You want the hinge preps to remain as properly aligned as possible.

    Once you have shimmed the door you can replace the hinges.   Start with the top.  Install each leaf with two screws only, not quite fully tightened.  Then move on to the next hinge, then the next, until they are all replaced.   When each hinge is in place with two screws in each leaf, tighten all the screws and try the door.  If the hinges bind or make noise, something is amiss and needs further adjustment.

    If applicable, put masking tape over the strike plate and close the door.  Is the door happy to remain closed, or does it want to spring open?  If it wants to spring open, chances are the new hinges aren’t quite as thick as the old hinges and need to be shimmed.  Support the door with wood as before and inspect the hinges.  Both leaves should be flush.  If they appear to be inset, shim them out with very thin slices of wood that are the same height as the hinge prep.  Continue as necessary until when tested the door is stable when fully closed.

    Troubleshooting

    If the hinges bind or make noise, remove the screws from one leaf of the middle hinge and gently pry it out of the hinge prep.  Test the door again.  If the door still binds or makes noise, put the screws back in the middle hinge and try removing the screws from one leaf of the bottom hinge.   By this method you should be able to isolate the hinges that are binding and then look closer to determine the exact problem.

    If, as you are working, you find that the hinge preps aren’t lining up so well, the door may have settled on the hinges – particularly if they are plain bearing, five knuckle steel butt hinges and they have been there a long time or had heavy use.  You may find that you have to shim the door up just a bit more to get the hinge preps to line up right for the new hinges.

    If there is no possible way to get the hinge preps to line up right then you may be dealing with a deeper issue than simple hinge replacement.  Your best choice might be to put the old hinges back and then decide whether you want to replace the door, frame, or both, or whether you can use a surface mount continuous hinge instead.

    Click here to read more about hinges.

     

    Wiring Through a Door

    AKA coring the door or drilling a raceway.

    Like Moses leading the Hebrews across the Red Sea, you must work a miracle to bring electricity from the hinge side of the door to the lock side.  Luckily it is a miracle on a much smaller scale.  Moses had to deal with millions of gallons of water and miles of sea bottom whereas you only have to deal with a few feet of wood.   So relax.

    Raceway Reasons

    The best way to get a wire raceway into a door is to order the door with it already built in.  This is especially true of hollow metal doors which often have cross members inside at angles to where the through-wire needs to go.  However, that would require planning in advance – a rare occurrence these days, it seems.    Lack of planning is the main reason that field-drilling a raceway becomes a necessity.

    Coring the door is usually the best option whenever you are installing an electric lockset.  This is true whether you use a door cord or an electric hinge.  The safest place for the wire is inside the door.

    You will probably also need to drill a raceway if you are using an electric strike in the inactive leaf of a pair of doors.   Usually you will also need a door cord, electric hinge or other power transfer.

    Horizontal vs. Vertical

    Electric Through-Wire Hinge

    It is possible to drill a raceway with the door still up.  I have done it but I don’t recommend it.  It takes nerves of steel and a stiff, sharp drill bit.  You need a decent sized bit that won’t bend right or left on you as you try to drill straight, and you need to make sure that the door doesn’t move on its hinges while you are drilling.

    I found that taking the door down and standing it on edge in a homemade door stand is the easiest for me because:

    • The door is much less likely to move while you are drilling it
    • Using a level to guide you is much easier, and
    • Gravity is on your side

    Constants

    Certain constants apply to either horizontal or vertical drilling.  In both cases I recommend a 3/8-inch by 3-foot drill bit.  If the door is more than 3 feet wide, drill it from both sides or get a 4-foot bit.  I prefer to drill from both sides because it’s a lot easier to drill straight for 18 or 24 inches than it is to drill straight for 3 or 4 feet.

    Simple Door Stand

    If you have a drill with a built-in level, use it.  If your drill does not have a built-in level, any level will do.  Just put it against the door anytime you want to check the angle at which you are drilling.  Determine if the door has a beveled edge and don’t let the bevel skew your path through the door.  Make sure your drill bit remains parallel to both the interior and exterior surfaces of the door.

     

    Drilling a raceway across a door is a challenge, but all it really takes is good focus and an ability to drill a straight hole.  If you are challenged in the latter aspect, you might consider a drilling tool like the Security Door Controls product shown below.   If you have many raceways to drill, a tool like this one is a great idea.

    Security Door Controls 7000IDF Door Drilling Kit

     

     

    Exit Device, Panic Hardware and Crash Bar Basics

    Introduction

    The terms “crash bar”, “panic hardware” and “exit device” all mean the same thing.

    Precision Apex 2000 Series Rim Exit Devices by Stanley

    Exit devices are used on doors in the path of egress in buildings built to accomodate numbers of people.  Facilities like schools, hospitals, goverment buildings and large residential buildings all use them.  Fire rated exit devices are used on fire rated doors.  Most interior doors that require exit devices, especially stairwell doors, are fire rated.

    Fire Rated Exit Devices

    Fire rated openings require fire rated exit devices. Fire rated devices are so designated by Underwriters Laboratories. I am told that UL tests them by mounting the device on a fire rated door and setting the door on fire, letting it burn for a time, and then blasting the door full blast with a fire hose. If the door opens, the device fails the test and cannot be sold as a fire rated exit device.

    Non-fire-rated exit devices are used mainly on exterior doors.

    Dogging Feature

    One of the chief differences between a fire rated exit device and a non-fire-rated exit device is called the “dogging” feature. A dogging feature allows the user to “dog the bar down” using a hex wrench or standard key, leaving the door unlatched. Since fire rated devices must always postitively latch, they never have a dogging feature.

    Narrow Stile Exit Devices

    The term, “lock stile”, refers to the part of a panel door or aluminum-and-glass storefront door onto which an exit device or other lock is installed. Many aluminum storefront doors one encounters in the world have lock stiles only 1-3/4 inches to 2 inches wide. If you need an exit device for such a door, you need an exit device for a narrow stile application.

    Exit Device Types

    The four main types of exit devices are:

    • Rim
    • Mortise
    • Surface Vertical Rod
    • Concealed Vertical Rod
    • Mid-panel

    See examples of rim exit devices at:

    http://www.sargentlock.com/products/product_overview.php?item_id=86

    and

    http://www.sargentlock.com/products/product_overview.php?item_id=57

    See an example of a surface vertical rod device at:

    http://www.sargentlock.com/products/product_overview.php?item_id=56

    See an example of a mortise exit device at:

    http://www.sargentlock.com/products/product_overview.php?item_id=59

    See an example of a concealed vertical rod exit device at:

    http://www.sargentlock.com/products/product_overview.php?item_id=60

    Specifying Exit Devices

    Exit device choice is based upon the door. As mentioned previously
    if the door is fire rated, the exit device must also be fire rated.
    If the door is a narrow stile door, an narrow stile application exit
    device is required.

    In addition, you need to know the width of the door. Exit devices
    come in different lengths to accomodate different door widths, so
    that the touchpad of the exit device provides the coverage required
    by national and local life safety and/or fire code. Door thickness
    could also be a factor, especially if you are going to need exit device
    trim, that is, a lever, doorknob or thumbpiece that allows people
    to unlatch the door and enter from the outside. I will discuss exit
    device trim shortly.

    For a pair of doors (otherwise known as a double opening, or a set
    of double doors), the best choice is usually a surface or concealed
    vertical rod exit device. In this case you also need to know the door
    height.

    It is possible to lock a pair of doors using one rim or mortise exit
    device and either a vertical rod exit device or a set of flush bolts,
    but these solutions (while perhaps saving a little money) present
    other problems. If you use a rim device on the active door, then the
    strike (the part you will be mounting on the inactive door to receive
    the latch of the rim device) is called quite appropriately a “pocket-ripper”
    strike, since it hangs into the opening at pretty much trouser pocket
    level. Use of a mortise exit device on the active leaf eliminates
    that problem, but it will not work as reliably as would two vertical
    rod devices, and would save very little money.

    The choice between concealed and surface vertical rod exit devices
    should be a simple one. If you are having doors made, have the door
    manufacturer install concealed vertical rod exit devices at their
    factory. If you are installing a vertical rod device at a job site
    on existing doors, then use surface vertical rods.

    Concealed vertical rod exit devices are preferable because they are
    protected from damage by the door. However, it is an especially skilled
    installer who can install one in the field, and at that, it is a time
    consuming and difficult job.

    Mortise exit devices offer superior durability, and are otherwise
    the best choice when retro-fitting an exit device to an existing door
    that already has a mortise lock.

    Exit Device Trim

    The exit device goes on the inside, or interior side of the door,
    and exit device trim goes on the outside. Exit device trim is available
    in different functions. Below are the most common functions:

    • Key locks and unlocks lever handle or thumbpiece. Trim can be
      left unlocked for periods of time allowing free entry.
    • Key retracts latch. Exit device is always locked from outside,
      entry by key only. Not available on some vertical rod exit devices.
    • Key unlocks trim only while key is inserted. User turns key, operates
      control for entry. Trim is relocked when user removes key.
    • Passage function: trim is always unlocked allowing free entry.
    • Dummy trim: trim is rigid, usable as a handle to pull the door
      open when either the bar is dogged down using the dogging feature
      (see above) or when the latch is retracted or the device released
      by other means.

    Exit Device Options

    Exit devices are available with a wide variety of options that increase
    their functionality. These include:

    • Alarm
    • Touchpad or latchbolt monitoring switches
    • Electric latch retraction
    • Electric dogging
    • Delayed egress

     

    When Your Key Won’t Turn

    Someday you might come home or go to open up your business and find that your key won’t turn at all, not even a little. There are several reasons this might occur.

    At right, illustrations show the operation of a standard pin tumbler lock. When you insert your key, the key raises the pins to the point where the division between the top pins and the bottom pins aligns with the division between the plug and the bible of the cylinder, allowing the plug to turn.

    Sometimes dust and dirt collect inside the lock cylinder. When that happens the dirt can cause the pins to stick in a partially raised position, preventing the plug from turning. In most cases a spritz of dry lubricant will be sufficient to free up the plug and allow you to open your door. Simply spray the lubricant into the keyway and insert the key a few times to work the lubricant into the mechanism. If this method does not work you may need to use a more solvent-based lubricant like WD-40 to loosen the dirt. Locks exposed to the elements sometimes collect a lot of dirt.

    If your key will only go in part way, this could still be the same problem, or there may be an obstruction in the keyway. Illumination of the keyway reveals that the bottom pins hang down into the keyway. In the event that lubricating the lock is ineffective, slide a thin piece of wire into the lock along the bottom of the keyway, avoiding the pins, and feel for an obstruction. If the piece of wire will not go in as far as the length of the blade of your key, there may be an obstruction present. At this point you might want to call a locksmith, however, you can gently work your way past the pins and try to go over the obstruction in order to try to coax it out. This process can take a lot of patience and skill, and it is possible to make the problem worse if you are heavy handed with the pins.

    From Wikipedia

    Should lubrication fail to free up your lock and you can find no obstruction, your lock may have a more serious malfunction, such as a pin chamber worn enough to allow a pin to get stuck at an angle, or a corroded pin that is frozen in place and will not budge no matter what. In these cases you need a professional to gain entry for you and repair your lock. If you succeed in freeing up your lock but find that the problem is reoccurring with increasing frequency, it’s probably time for you to replace your cylinder.


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