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Full Height Housings for Electromagnetic Locks

December 29, 2011 access control / builders hardware / door hardware / security hardware
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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

December 26, 2011 access control / door hardware / Life Safety Hardware / security hardware
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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.


Exit Device Checklist

December 1, 2011 builders hardware / door hardware / hardware sales wars / Life Safety Hardware / security hardware
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See also Exit Device Basics

Here are a few questions you need to be able to answer before you order exit devices:

  • Is the door made of wood, hollow steel, Fiberglas, aluminum and glass, or all glass?
  • Is the door is fire rated or non-fire rated?
  • Door width if single door or pair of doors with center mullion?
  • Door width and height if for a pair of doors without mullion?
  • Door thickness?
  • Exit device finish?
  • Will this be an exit-only device, or will there be outside trim?
  • If there is outside trim, what function is it?

It will save you time and aggravation if you know the answers to these questions before you call your hardware vendor.

You may also want one or more of these or other mechanical options:

  • Cylinder dogging (not available on fire rated devices)
  • Less bottom rod (for vertical rod exit devices)
  • Double cylinder (trim locked or unlocked from inside secured space)

There may also be electrified options:

  • Does the exit device need to have electrified trim?  If so, fail safe or fail secure?
  • Does the exit device need to have electric latch retraction?
  • Does the exit device need to have push pad or latch monitor switches?
  • Do you need a delayed egress exit device?

Save time and money by gathering the necessary facts before shopping for exit devices.

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