Electromagnetic Locks for Safety & Security

April 2, 2018
Today, electromagnetic locks are used safely in a wide range of access control applications

Electromagnetic locks are a popular method to control the locking and unlocking of access controlled swinging doors.

Advantages of Electromagnetic Locks:

Electromagnetic locks are reliable because they do not have any moving parts.

Electromagnetic locks are easy to install since they are comprised of two major components and require three screws to install. Many individuals involved with the installation of access controls are not locksmiths or mechanically oriented and prefer to not have to deal with real mechanical locks.

Electromagnetic locks are intrinsically Fail Safe. When power is cut to an electromagnetic lock, it unlocks.

Drawbacks of Electromagnetic Locks:

They do not have an integral way to unlock like most mechanical locks do and can only be unlocked by switching off power to it.

Because they can only be controlled mechanically, they require a safe and properly designed control system to ensure safe egress can be assured in all circumstances.

Because of the unique characteristics of electromagnetic locks, and because of some unfortunate past accidents involving doors equipped with electromagnetic locks, many municipalities banned their use completely.

That unfortunate history helped to spur development of building codes and life safety created a series of codes setting up the requirements for approved electromagnetic lock installation. These codes are revised regularly with the intent to make electromagnetic locks totally safe. The security industry has also developed standards for electromagnetic lock standards defining performance and specifications

All the codes apply to how the electromagnetic lock is (locked or unlocked) controlled for egress rather than how it controls entering, since egress is where life safety is the concern.

The codes have undergone some recent revisions. An electrical switch contact is required to control (lock and unlock) an electromagnetic lock.

Since most of us who use electromagnetic locks are familiar with the existing various codes, we conduct our proposals and installations so that our systems will be accepted by the AHJ, or at least be substantially acceptable, and then we can make adjustments and alterations as the AHJ requires. If we are responding to a request for a quotation based on a spec developed by an architect or other party, it does not relieve the installer from confirming the locking device is appropriate and the installation environment is consistent with the relevant code.

There are two different model codes (sets of requirements) for the control of electromagnetic locks.

These model codes are the basis upon which the building codes for structures and municipalities are based. AHJs have the ultimate power to determine what is allowed and what is not allowed, but they generally will use the model code as a source of information and as a guideline for their own requirements.

Any door using an electromagnetic lock must comply with one or other of these codes, but additionally are also subject to codes specific to the building occupancy type and usage.

In some situations a door may also be subject to provisions in UL 294 The Standard For Access Control System Units.


Sensor Release Of Electrically Locked Egress Doors (formerly called Access-Controlled Egress Doors) also Sensor-Release of Electrical Locking Systems applies to doors which unlock when an individual approaching the door to egress is sensed by a motion detector.

On these doors, the electromagnetic lock must also release with:

  • loss of power to sensor
  • loss of power to lock or locking system
  • activation of building fire alarm or automatic sprinkler system (door must remain unlocked until the fire system is reset)

The door control system must also include a manual unlocking device (pushbutton) located between 40 and 48 inches above the floor and within 5 feet of the door to which there is ready access, and which is marked “push to exit.” Pushing the button must directly interrupt power to the electromagnetic lock independent of other electronic devices in the system. Once the button is pressed, the door must remain unlocked for at least 30 seconds


The other applies to doors with door mounted hardware which incorporate a switch, which when actuated, releases the lock. Formerly titled ‘Electromagnetically Locked Egress Doors’ or ‘Electrically Controlled Egress Door Assemblies,’ now renamed ‘Door Hardware Release of Electrically Locked Egress Doors’ or ‘Door Hardware Release of Electrically Locked Egress Door Assemblies’.

These doors:

  • must be readily operated with one hand and under all lighting conditions
  • must directly interrupt power to the electromagnetic lock independent of other electronics and
  • must unlock immediately upon loss of power to lock or locking system

If panic hardware is required (by another applicable code (e.g. NFPA 80), operation of the panic hardware or fire exit hardware must release the lock.

Note that this section does not require the door to unlock upon activation of the fire protective system.

This category is also covered in a new BHMA (Builder’s Hardware Manufacturer’s Association) Standard titled ANSI/BHMA A156.41-2017, Standard For Door Hardware Single Motion To Egress.

This standard describes requirements for doors and door hardware to comply with Code Requirements for single operation egress, to allow a door to be opened for passage by releasing all latch and locking mechanisms on a door with one motion in a single linear or rotational direction using only one hand and without the use of a key, a tool, or special knowledge or effort.

For a door to meet requirements for single operation egress, it shall not have more than one single operation release hardware device.

The recently revised ANSI/BHMA A156.23 -2017, American National Standard for Electromagnetic Locks. A156.23-2017 establishes requirements for electromagnetic locks and includes cyclical, dynamic, operational, strength and finish tests. This product is used for access control. For further information about electromagnetic locks, consult the full standard.

Building Codes: Builders hardware provides several attributes that are essential to building safety and performance, including egress and fire protection. BHMA electromagnetic locks are designed to comply with all applicable requirements. Electromagnetic locks used on labeled fire door assemblies shall be listed or labeled for fire doors by a nationally recognized independent testing laboratory and be subject to a periodic in-plant follow-up inspection service.

SDC Maglock Products

Security Door Controls offers a large catalog of electromagnetic products suited for every imaginable scenario.

The EP17624 EMLock Series Explosion Proof Magnetic Lock is specifically designed for applications where flammable vapors are cause for concern, like clean room, chemical plant, or refinery environments by eliminating the sparks or arc in the magnetic lock.

It is UL listed for use in hazardous locations CLASS 1, DIVISION 2.

• Explosion Proof Epoxy Sealed to eliminate sparks

• No moving parts, virtually maintenance free

• Corrosion Proof

• Door Status Sensor

• 628 Clear Anodized Aluminum housing

• Classified for Class 1, Division 2 Hazardous Locations

The EP17624 EMLock Series Explosion Proof Magnetic Lock is intended to be used in the following atmospheres: Acetone, Ammonium Hydroxide, ATSM fuel C, Benzene, Methyl-Ethylketone, Diethyl-Ether, 2-Nitropropane, Ethyl-Acetate, Furfural, Normal Hexane, Methyl Alcohol.

Operating temperature for the magnetic lock will not exceed 185° F (85° C). Maximum ambient temperature is not to exceed 104° F (40° C). For supply connections, use a suitable wire with a minimum insulation temperature rating of F (75° C).

This unit must be connected to a NEC (National Electric Code, NFPA 70) Class Supply Circuit rated for 24 VDC with a minimum current output of 0.5 amperes and output power of 12 watts. A UL Listed SDC 600 Series Power Controller is recommended.

For use with the explosion proof electromagnetic locks, SDC’s 499 Explosion Proof Exit Switch is a rugged accessory designed for hazardous locations. UL Listed, the 499 Explosion Proof Exit Switch is made from impact resistant, non-metallic PA6, glass reinforced antistatic material and is used at petroleum refineries, chemical/petrochemical plants and other processing or storage facilities where hazardous and corrosive environments exist.

  • Silicone gasketing on all enclosures and operators throughout
  • Operating Temperature of -50°C to +60°C
  • Complies with RoHS, WEEE, ATEX, EMC and Low Voltage directives

SDC’S 602RF 602RF Series 1 Amp Modular Access Control Power Supply provides a “clean” source of power - filtered to ensure against spikes and surges, properly regulated for consistent output, and offering short circuit and thermal load protection.

They combine the efficiency (low heat generation) of a switching supply and the rugged inductive load capability of a linear power supply. With a high-performance transformer and extra filtering added to the output stage, the 602RF provides protection to ensure longevity of all system components.

  • Field selectable 12 or 24VDC, regulated and filtered
  • Auto resetting output circuit protection
  • Isolated 13.5/27VDC battery charger
  • Low battery disconnect
  • Emergency release input
  • Field selectable UBC & California compliant manual power up
  • Input, output and battery status LED&s
  • 12 x 12 x 3 3/4 ; enclosure
  • Choice of output and door control modules

More Info: www.sdcsecurity.com

Locknetics WMG Series Mag Locks

Locknetics was the first electromagnetic lock I worked with, and I had several dialogs with the individual credited with the invention of the electromagnetic lock.

Allegion recently introduced Locknetics, an entirely new portfolio of electric strikes, electromagnetic locks and access control accessories, billed as simple solutions at a practical price point. Among those products are the WMG Series of surface mount electromagnetic locks. The WMG600 and WMG1200 are designed for high profile openings that require tamper-resistant locks with an aesthetically pleasing appearance.

Features and Benefits:

  • Sealed stainless steel housing for weather resistant applications
  • Optional mounting plate for quick, simple installation
  • Magnetic bond sensor included
  • Field Selectable 12/24 VDC
  • Available brackets for inswing and narrow frame doors


  • UL10C listed
  • UL294 listed
  • UL1034 listed including outdoor

More Info: www.allegion.us

Dortronics’ ML-1100 Series Mortise Lock & Pull

Aluminum storefronts are a common application for electromagnetic locks. Because electromagnetic locks have traditionally been mounted at the top of the door and frame, and because storefront doors are relatively flexible, pulling on a door with an electromagnetic lock often can result in the door warping, perhaps the glass breaking or the electromagnetic lock bond being broken.

The Dortronics ML-1100 Series Mortise Lock&Pull provides another choice for electronically securing storefront aluminum glass doors. The lock mechanism is an electromagnet installed into the swing side aluminum jamb. The armature is concealed, mounted into the handle, which is installed onto the pullside of the flush mount doors’ stile.

With this type of installation, the handle pulls directly against the electromagnet providing evenly spaced holding force and limiting the ability to rack the door. The ML-1100 uses a ten inch long, one thousand pound holding force electromagnet. The Fail Safe electromagnet current draw is 360mA @24VDC.

In addition to finish options for the ML-1100, there is the Magnetic Bond Sensor (MBS) option that provides a signal when the lock is properly energized and the magnetic field is holding the armature flush.

More Info: www.dortronics.com

Camden CX-93M-12LSs Shear Lock

Shear locks are indeed electromagnetic, but they also use an interlocking between the armature and the electromagnet. This enhances the holding power, and allows the shear lock to be deployed on bi-swinging doors.

Camden CX-93M-12LS shear lock is designed for swinging doors, where the lock can be mortised into the door and frame. The CX-93M-12LS has a remarkably low current draw, while providing 1,200 lbs. of holding force. The shear lock features stainless steel construction and is backed by a lifetime warranty.

CX-93M-12LS shear locks are ideal for exterior and interior swing doors where the use of a traditional electric strike or magnetic lock would be unattractive, impractical or prohibitively difficult. The shear lock and armature assemblies are recessed (mortised) into the door and the door frame, providing an unobtrusive high security locking solution.

• Compatible with all access and egress systems

• Rugged and compact design

• Stainless steel construction

• Selectable 12/24 VDC

• Selectable 3 to 12 second timer

• Bond sensor output (form c)

More Info: www.camdencontrols.com

BEA Maglock Products

BEA’s UL Listed Maglock with DS provides a standards compliant locking solution for retail, healthcare, banking and other high security facilities that require a UL listed security product.

UL Listed Maglocks can be used on hollow metal, wood, aluminum, glass and composite door materials.

The Maglock with DS is available in surface mount, single or double door configurations, with a holding force of 600 or 1,200 lbs. These locks include an adjustable 0 – 90 sec relock time delay, lock status sensor with visible LED and door status sensor.

BEA’s Br2-900 is a 2-relay logic module with built-in 900 MHz wireless technology. Designed to provide wireless MC25 functionality, it is ideal for applications requiring sequencing of electric locking devices and automatic door activation.

Additionally, Day / Night Mode on the Br2-900’s wireless receiver enables the user to designate “secure” or “unsecure” access for controlled entry points. Push plates with wireless transmitters can be programmed to operate during specific time periods (controlled via DRY Day / Night Input).

BEA’s Universal Mode allows pre-learned Universal Transmitters to function directly out of the box...no programming required, saving time and enhancing accessibility.

The Br2-900 is compatible with all existing BEA 900 MHz transmitters and products, plus the Universal Transmitter.

Its logic module with integrated 900 MHz wireless technology eliminates the need for separate logic module and wireless receiver.

BEA also offers its Universal Keypad Family. Available in both single gang and slim-line surface mount, these devices are designed for integration into security systems with electromagnetic locks, electric strikes and other equipment requiring on/off or momentary control inputs.

All programming is completed entirely from the keypad. Non-volatile memory means codes settings will remain in the event of power loss.

More Info: www.beasensors.com

Securitron M680E EcoMag 

The new Securitron M680E Series with EcoMag technology from ASSA ABLOY delivers the same intelligence, style and convenience as the previous Securitron M680 series, but with up to 80 percent reduction in energy consumption.

Increased holding force of 1,200 pounds adds an increased level of security to the access point.

Optional door prop sensing allows the magnet to de-energize the coil when the door is held open for extended periods, dropping the power draw as low as 20mA at 24V.

All-in-one optional integrated accessories provides flexibility to customize as needed.

Product Features:

• 1,200 lbs holding force

• Strike plate mounting template ensures rapid alignment upon installation

• Lower power consumption allows for use of smaller backup batteries and decreased operating costs

• LED Indicator shows lock status

• Tamper Switch sends an alarm output if the cover is removed and is selectable to NO or NC

• Autosensing dual voltage with microprocessor technology

• Adjustable automatic relock timer (0 to 30 seconds)

Available Options:

  • Integrated BondSTAT lock sensor
  • Integrated Door Position Switch
  • Integrated Door prop sensing allows the magnet to de-energize the coil, dropping power draw as low as 20mA at 24V
  • Integrated Passive Infrared Motion Detector

The M680E is being used predominately in aesthetically demanding applications such as office buildings, universities, hospitals, and banks.  The target audience for the product is very broad, from locksmiths adding retrofit security, to system integrators or environmental consultants working on new construction projects.

When I began using maglocks, we often had to re-purpose security motion detectors for use with electromagnetic locks. There many drawbacks doing this. I was happy when they came out with an access control specific REX sensor.

The Securitron XMS Exit passive infrared (PIR) motion sensor request to exit (REX) device reliably detects motion near a door and releases its lock. Versatile mounting options and an easily adjustable infrared beam pattern provide optimal coverage of the egress area for smooth, hands-free lock release and exit.

More info: www.securitron.com

Products mentioned in this article may only be some of the products  available in this hardware group.  Contact your local locksmith distributor for their suggestions on possible additional product lines.

About the Author

Tim O'Leary

Tim O'Leary is a security consultant, trainer and technician who has also been writing articles on all areas of locksmithing & physical security for many years.