Electromagnetic Locks for Safety & Security
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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 CONTROLLED TYPE: 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 SWITCH ON DOOR CONTROLLED TYPE: 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