Today’s "smart" electromagnetic locks have expanded the capabilities of maglocks to new levels, creating opportunities for locksmiths to provide higher levels of security to meet and exceed customer requirements.
Electronic access control can be provided for high, medium and low level security doors using electromagnetic locks alone and in combination with other lock mechanisms. Traffic control electromagnetic locks are used to control the movement of people throughout a building or facility. Electromagnetic locks/holders keep cross-corridor and area separation doors retracted for normal traffic flow. Moisture-proof electromagnetic locks are used on perimeter entries and gates.
Going beyond openings, a number of showcase manufacturers incorporate electromagnetic locks for ease of security. Since no physical contact with a lock or locking mechanism is required, there are few limitations. An electromagnetic lock provides a much larger locking area than a conventional latch or bolt. This larger locking area can be configured to instantly lock once a glass or clear material showcase door, base or cover is in the secured position.
The electrical current travels through the circuitry and the wire coils surrounding the ferrous metal plates become instantly magnetized. When the face of the electromagnet is within range of the ferrous metal armature, the armature is magnetically drawn to the electromagnet, becoming magnetically bonded.
Electromagnetic locks are Fail Safe, needing continuous power to remain locked. Depending upon the application, it can provide the primary locking mechanism (with appropriate backup battery power) or a secondary (daytime/business operation) locking method. No physical locking mechanisms attach conventional electromagnets and armatures. When power is removed, the electromagnetism disappears, the electromagnet and the armature separate.
The development of the electromagnetic lock for door locking operation is relatively new, as the introduction occurred around 1969. Like many developing technologies, time was required to discover some of the problems and develop "fixes." A number of the early electromagnetic door locks suffered from residual magnetism, which resulted in some difficulty opening an unlocked door, as the armature did not easily separate from the electromagnetic lock. As a result, authorities and government agencies discouraged the use of electromagnetic locks. Then instant release electronic (degaussing) circuits were incorporated into electromagnetic locks to dissipate any residual magnetism. The processes removed any residual magnetism each time power was removed from an electromagnetic lock.
Holding force is determined by the number of and the size of the lock's ferrous metal components, and the AWG and number of wire coils that surround the ferrous metal components. The holding force is determined by using a preset value of the surface area of the armature that contacts the magnet. The actual surface area contacted often does varies because installations are not always exact. For this reason, it is a good idea to consider the holding force of an electromagnetic lock to be up to the manufacturers stated value.
The strength of an electromagnetic locks' holding power depends upon the face-to-face alignment between the electromagnetic face and the armature. For this reason, many armature installations are spring loaded, using a centralized bolt or having the armature built into a spring loaded mounting bracket. This enables the armature to tilt in order to take full advantage of the surface area contact with the face of the electromagnetic lock.
For optimum contact, electromagnetic lock manufacturers offer monitoring to notify if the minimum armature contact with the lock face is below the set standard. Some electromagnetic locks offer anti-tamper switches that signal the removal of the wiring access cover. Some manufacturers of low voltage detection notify the access control or alarm system when the voltage drops a specific percent. A voltage drop significantly reduces the maglock’s holding force.
The basic installation of the electromagnetic lock is mounted onto the jamb on the secure side of the door. The most common installation is onto the header near the lock edge of the door. The armature is mounted onto the secured side of the door face. To maximize the face-to-face alignment, which maximizes the strength of the electromagnetic lock bond, most manufacturers offer mounting brackets and filler plates to accommodate different jamb configurations. Mounting brackets are designed to slide the magnet in position, which eliminates holding the magnet in place while starting and installing mounting screws. Additional improvements include the wiring chamber and placement of the anti-tamper switch in the wiring chamber.
Conventional electromagnetic door lock holding forces range from under 600 pounds to more than 1500 pounds. Electromagnetic locks are designed to be either surface mounted or mortised into the doorjamb. There are electromagnetic locks designed for sliding doors and doors with wide gaps or installation issues. Some manufacturers offer "low profile" or "compact" locks to accommodate openings that are more complex.
Before purchasing an electromagnetic lock, know the door and jamb materials, the application, interior or exterior/swing or sliding and the amount of foot traffic. Some doors are rigid, built with solid wood cores or rigid metal components. Jambs can be filled, rigid or built onto a finished wall having no real support.
Since an electromagnetic lock requires a rigid bond, a flexible door or jamb may not provide the desired level of security. For example, aluminum glass storefront doors provide minimal security when installing an electromagnet into the header as the only locking mechanism. These doors are susceptible to permanent damage when the door handle is pulled repeatedly while the door is in the locked condition. The storefront door has a glass panel that can easily be removed or broken. In addition, an aluminum glass storefront doorframe can easily flex or even bend. For most applications, installing an electromagnetic lock on an aluminum glass storefront door should be for traffic control (daytime hours), not security.
If security is required, consider mounting the electromagnetic lock at the vertical centerline of the lock edge of the door. Note: This type of installation can only be installed on doors that will still meet ADA and code requirements as the door width will most likely be decreased. This location prevents the electromagnetic lock bond from being easily "racked" apart.
For single electromagnetic lock applications, consider the Dortronics ML-1100, a mortised 1000-pound holding force electromagnetic lock that has the armature installed into the surface-mounted door pull. Because of the location of the mortised electromagnetic lock, no mechanical advantage is gained when force is applied to the pull handle.
For a higher level of security, consider installing a ROFU 8122-002 Two Point Locking Door Magnet. Two 1500-pound holding force magnets are interconnected within a full length extruded aluminum housing, providing up to 3000 pounds holding force at the top and bottom of the swing side of the opening. To accommodate ADA, after installation the doorway must have a minimum of 32 inches clear width with the door open 90 degrees.
To compensate for door and jamb imperfections, SDC 1560 Series Surface Mount Hi Shear EMLocks incorporate a “floating” armature assembly and special alloy steel locking “tabs” on both the lock and armature assemblies. They can be vertically and laterally adjusted to compensate for wide door gaps and warped or misaligned doors. Configurations enable installation as concealed and surface mounted. The surface mounted 1561S Hi Shear EMLocks can be used on Herculite Doors with top rails in addition to hollow metal and wood doors and frames. These locks provide up to 2000 lbs. holding force.
The use of electromagnetic lock mechanisms for gate locks is becoming an increasing popular. Electromagnetic gate locks usually vary from standard electromagnetic locks. A built-in conduit fitting prevents moisture from getting into the electronics, and an extra-long wire cable can be run to an electrical box. Some gate locks have a floating armature that compensates for misalignment of pedestrian and vehicle gates. Some manufacturers offer remote lock status that indicates if the magnet is locked or unlocked.
Over the years, electromagnetic lock manufacturers have begun to introduce “smart” electromagnetic locks equipped with onboard microprocessors and sensors. An early form of “smart” technology for electromagnetic locks is auto-sensing voltage with microprocessor technology, which increases the lock's life expectancy and reduces power consumption.
By incorporating “smart” technologies, electromagnetic locks have new and expanded capabilities including free egress, delayed egress and early warning. Some of the “smart” technologies include Passive Infrared Request to Exit (PIR REX), surveillance cameras, sensors, switches and mechanisms.
The RCI EW8310 Early Warning Electromagnetic Lock is designed to sense when an intruder is attempting to gain access through a locked door. The patented built-in red/green sensor of the RCI EW8310 detects attempted forced entry and can activate an auditory and visual alarm before the integrity of the door is compromised. The early warning electromagnetic lock offers holding force up to 1200 lbs.
The Dynalock 3006 Series 1500 lbs. Holding Force Electromagnetic lock has an integrated infrared sensor providing self-contained free egress capability. When an individual attempting to egress approaches the door, the built-in Egress Control Logic disengages power, enabling the door to be opened. Access can be granted by either removing power (two wire control) or using the access input with adjustable relock delay. Additionlal inputs include external egress and PIR disable. The PIR can be maintained for up to an hour without power, allowing two-wire control only. Outputs include optional Door Status Monitor, Dynastat Magnetic Bond Sensor, Anti-Tamper Switch, and egress monitor (standard) with adjustable relock delay. The 3006 Series Electromagnetic Lock circuitry can shunt security alarm systems for access and egress.
The RCI 8310-IQ IntelliMag has been designed to recognize the armature plate. This prevents anyone from using a separate armature plate to deceive the magnet with in order to enable the door to stay open. Each individually encoded armature plate is registered to match its own electromagnetic lock. The Lock Status Sensor recognizes when the compatible armature is bonded. The 8310-IQ IntelliMag Series features a built-in time delay for instant release with adjustable relock. The IntelliMag is available with single or dual electromagnets.
Video confirmation is the latest option being offered with "smart" electromagnetic locks. The RCI Delayed Egress Electromagnetic Lock, DE8310 Series offers a built-in camera as an option with voice, part number DE8310CV or sounder. The camera module provides continuous video signal to DVR via the provided BNC connector.
Securitron offers two electromagnetic locks with video options. The UL 10C fire-rated and UL 1034 Burglary-Resistant Securitron M680 Series 1100 lbs. holding force electromagnetic lock is available in different configurations including the "smart" technologies. Choices include color or black and white video surveillance cameras, passive infrared, Request-to-Exit, autosensing dual voltage with microprocessor technology, adjustable automatic relock timer (0 to 30 seconds), door position switch and BondSTAT, Securitron's patented lock bond sensor.
Having a magnetic lock equipped with built-in PIR REX, simplifies the installation by having the sensor area originating from the M680. The beam pattern can be adjusted for a hallway or door approach. When installing this REX equipped electric strike, a separate continuous power input of up to 27.5mA @12VDC/11mA @24VDC is required to power the REX.
Mounting an analog video surveillance camera into the M680 body enables discreet surveillance of area from a height that will include videoing facial images. When installing this analog video surveillance camera and REX equipped electric strike, a separate continuous power input of up to 250mA @12VDC/100mA @24VDC is required to power the video camera and the REX.
The Securitron M380 Series, the 600 pound "smart" electromagnetic locks, combine auto voltage-sensing microprocessor, the patented BondSTAT, door position monitoring, adjustable automatic relock timer (0.5 to 15 seconds) and advanced options including integrated camera and/or REX. Unlike its more powerful sibling, the M680, the M380 Series are not UL fire or burglary rated. The M680 and M380 Electromagnetic Locks are designed for indoor use only.
For delayed egress applications, the DynaLock 3101B Series Delayed Egress Electromagnetic Lock incorporates a 1500lbs holding force electromagnetic lock. This single delay egress lock is designed for outswing interior applications. The 3101B Series conforms to NFPA101 Life Safety Codes and high security needs at the same time. The "Smart" on-board microprocessor controlled 3101B system offers custom factory programs, an Opto-Electronic System Sensor, watchdog circuit and a lifetime warranty.
