Volume 38, Issue 11, November 2003
Electric Strikes Are
Making it Big in Storefronts
By Tim O'Leary
Strikes such as the Trine 3458 and 3258 are designed for use in demanding applications.
Electric strikes (also referred to as electric releases), are gaining new levels of acceptance as merchants and business owners endeavor to protect their customers, employees, their inventories and themselves against any number of unthinkable crimes, which fill the airwaves and newspapers in most regions of the country, and the world.
We are a more dangerous society than ever before, or to put it more accurately, everyone is more aware of security and safety. What might have been laughed off as paranoia a few years ago may now be regarded as just common sense today.
Doors: What are They Good For?
The two most important functions of a door are to facilitate egress in emergency situations and to prevent intruder access at other times. Electric door hardware will permit the installation of any number of popular security related systems, such intercom entry, remote door control and access controls. Electric locking devices used for storefront applications include:
• Electromagnetic locks;
• Electromechanical locks; and
• Door strikes (releases).
Electric locks are classified as either fail-secure (normally locked; apply power to unlock) or fail-safe (normally unlocked; apply power to lock).
The traditional electromagnetic lock is comprised of an armature, which is mounted on the door, and coil, which is mounted on the doorframe. The physical mounting and operation of an electromagnetic lock is rather simple, as it is comprised of only two components.
Electromagnetic locks are always fail-safe. When power is applied to it the magnet attracts the armature, and the door cannot open until power is removed. But, because there is no integral means on an electromagnetic lock to unlock it (no lever, paddle or cross bar), electromagnetic locks can be dangerous to building occupants unless a properly designed control system has been installed, such as a UL-listed power supply, request-to-exit controls (R-E-X), override key switch and an interconnection with the building’s fire alarm system. These items, and the additional labor required, can cost more than the electromagnetic lock.
Additionally, building codes and the National Fire Protection Association Life Safety Code, usually enforced by the local authority having jurisdiction, restrict and regulate the use of electromagnetic locks. Installing an electromagnetic lock should not be taken on casually, because if it is misused there could be significant repercussions. Left: The 3258 has a 1-inch backset, so it can be used in most frames without interference.
Other locking devices, which we’ll refer to as electromechanical locks, include those such as shear locks and electrified deadbolts. Shear locks, which are always electrically fail-safe, combine electromagnetic holding power with mechanical latching, and all of the safety issues that apply to electromagnetic locks apply to shear locks. Electrified deadbolts do not use magnetic armatures, but pose a similar set of issues. Electrified deadbolts are available in both fail-safe and fail-secure. Both shear locks and electrified deadbolts are subject to a variety of mechanical failures if the doors upon which they are installed become misaligned. Unfortunately, the potential for the mechanical portion of the lock binding up on a door and impeding egress in an emergency makes them a less desirable choice for openings along the path of egress.
Both electromagnetic locks and electromechanical locks create a security issue: they unlock if power to them is lost, and usually neither can be used with existing or standard door hardware and locks in place.
Electric strikes typically are latching type devices that mount in a doorframe in the position where a strike plate would be normally. Electric strikes usually utilize the existing lock on the door.
Although there has been much rhetoric about the advantages of the no-moving-parts design of electromagnetic locks compared to electric strikes that have moving mechanical parts, a quality electric strike, properly rated for the duty and weight of the door it controls, not only will provide excellent service, but it will be less involved to deploy and will provide a safe and secure locking system (occupants will be able to safely egress).
Electric strikes utilize existing door locks and hardware. This means that whether they are fail-safe or fail-secure the existing lock trim will continue to function under any condition and thereby permit free egress.
Also, electric strikes usually mount in an area of the doorframe that does not place stress on the frame and glass as do many electromagnetic, shear and bolt locks that are mounted at the top (or bottom) of the door.
If electric strikes have a bad rap, it is primarily for the following reasons:
• Shopping by price rather than by rating can lead to disappointing results;
• Electric strikes are often installed on doors that needed adjustments or repairs; and
• Electric strikes are sometimes not matched to the door or the duty cycle properly.
Select By Rating, Not Price
Although to some extent every customer is cost-conscious, do not succumb to the lure of selecting an electric strike because of low cost. As is the case with other door hardware items, such as closers and hinges, selecting an electric strike solely on the basis of price almost guarantees that the device will not perform satisfactorily. On the other hand, if a product has the appropriate ratings and listings for your application, don’t let a good price stand in your way either.
Streamlined manufacturing, smart engineering and simplified marketing channels have made possible the introduction of some great values in a wide variety of door hardware and electric strikes.
Wrong Door Installations
A significant number of door strike failures can be attributed to the fact that the door strike is placed on a door that is misaligned horizontally, where the door interferes with the jamb or the door closer is not functioning. Although horizontal alignment is important on any lock, when a door is supplied as new, aging and wear will occur over time and eventually most doors require adjustment. When a door strike is installed on a door that has been in service for a while, deterioration will have begun, and the new strike may already be misaligned. (This may not be a big problem for door installation companies, but it is common practice for locksmiths and alarm dealers to ignore the condition of existing hardware on the door and forge ahead with an installation.)
Electric Strikes Not Matched Properly
Using the right tool for the job is essential for proper door strike operation. Selecting a strike that is designed for the frame and application means that the optimum level of security will be maintained on the door, the installation will be faster and the electric strike will function reliably. Selecting a door strike that requires minimal cutting on the jamb is advisable for several reasons:
Aesthetics: By not requiring major alteration to the jamb and by using a strike that looks at home in the frame, the installation’s appearance will be more acceptable to the client. Additionally, if the door strike is unobtrusive it will be less likely to draw attention from vandals or would-be intruders as an attack point on the opening.
Weakening of the Frame: Some door strikes require so much cutting to the doorframe that the structural integrity of the frame is actually jeopardized. You may have selected a door strike as strong as Fort Knox, but what good is that if you destroy the door system when installing it?
Disruption at Installation Site: For retrofits, the less a fuss you create on the site during installation the better off you are. Although the client wants that electric strike, he may not want you to shut him down for hours, spread debris and make noise. Of course, sometimes installations must be performed during business hours, but your customer satisfaction quota is exponentially inverse to the time you’re on the door. Using an electric strike designed to fit also means you’ll require fewer tools and will save installation time.
Providing electric door locks and systems is an important revenue source for many companies. An understanding of the options available for securing a door means you will be more profitable and your customers will be happier. You will also be able to rest assure that you have installed equipment that is enhancing the safety and security of the people who use your doors.
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