Unlocking The Mystery long as the battery life will allow. the system, several additional options can also be incorporated. Some of the options available include motion sensors, request-to-exit switches and door contacts, some of which might already be required depending on the application and the local building, fire and life-safety codes, not to mention the local authority having jurisdiction. panic hardware. Load The load, also know as the electronic lock-ing or release device, can be one of many types including mortise locksets, cylindrical or bored locksets, panic or fire exit devices, electric strikes or unlatch devices and elec-tromagnetic locksets — surface mounted or shear-type. The loads need to be specified as fail-safe or fail-secure, depending on the appli-cation, operation required and the codes having jurisdiction, including building, life-safety, fire and local codes. Fail-safe would be specified if a particu-lar opening needs to open when a fire alarm is engaged, which means that this type of function is locked only when there is power put to the device and unlocked when there is no power present. Fail-secure would be the opposite, locked when there is no power and unlocked when power is put to the device. Strikes And Electromagnetic Locks Electric strikes or electromagnetic locks can be used to further regulate who passes through access points, providing an even greater level of protection. Electric strikes are door release devices, usually solenoid-operated, that will unlock the door when electrical power is applied. An opening that requires a person to be “buzzed in” is equipped with an electric strike. The buzzing sound is created when a button is pushed, sending an AC electric charge through the device. This action disengages the device and allows the door to open. The operation just mentioned is a fail-secure mode of operation, the most com-mon function of an electric strike. A fail-safe configuration will operate in the reverse condition; normally locked when power is applied and unlocked when power is interrupted. If desired, the buzzing sound can be eliminated by using a DC power source. Electromagnetic locks mount on the fixed frame and a strike plate mounts on the moving door or gate. When the door closes, the strike plate automatically aligns with the magnet. The magnetic force then takes over, strongly securing the door. Release is achieved by switching off the power to the magnet. Electromagnetic locks are available in a range of holding forces. Facilities that demand greater security, such as a detention facility, will need mag-netic locks with holding forces that approach 2,000 pounds. Since electricity is required to power the magnet, all electromagnetic locks are fail-safe unless they are equipped with a back-up power supply. Electromagnetic locks operate on DC power and, unlike electric strikes, are silent when locked or unlocked. Both electric strikes and electromagnetic locks are commonly operated with a push-button switch, making them ideal for personnel-monitored openings, such as office suites and hospital ward entrances. CM www.cmmonline.com A Closer Look At Loads Electromechanical versions of mortise-locks, cylindrical locks and exit devices enhance access control, life-safety and convenience. Mortise locks fit into a mortise in the door edge and typically feature levers to operate a latchbolt. They provide greater torque resistance, security and a greater variety of functions than typical cylindrical locksets and are rec-ognizable by the separate key cylinder above the lever. Mortise locks can be applied to any door in a facility that requires latching or locking and doesnʼt require panic hardware. The brute strength of a mortise lock makes it a popular choice for securing sen-sitive areas. Cylindrical locks are a step down from the strength and durability of a mortise lock and are more appropriate for securing inte-rior openings. A cylindrical lock requires less door preparation than a mortise lock and is also less expensive and easier to install. Control The control, also known as the switch, can be a magnetic strip card reader, proximity reader, smart card reader, a motion sensor, push button or any type of device that turns an electrified locking device and/or off. These switches are operated by a variety of means, including electronic keys with similar technologies to their respective readers, again including magnetic strip card, proximity card or a smart card — an electronic key with a microchip capable of storing a large amount of information. Exit Devices Exit devices, also known as panic or fire exit hardware, allow safe egress while restricting access from outside a building. Exit devices consist of a push pad or bar which extends across the push side of the door. When depressed, the device retracts a latchbolt that allows the door to open. Think of these as a one-way valve through which people can exit but not enter unless authorized. Life-safety codes establish occupancy or space requirements that dictate which doorways must be equipped with an exit device. Rooms within education, health care and assembly occupancies with an occupant load greater than 50 persons will require Conductor The conductor, also known as the wire, is the final required piece of the puzzle. There are two factors that will affect the system in regards to the conductor: The amps and the distance of the wire. The more the amps and the greater the distance, the larger the gauge of the con-ductor required so that the voltage does not dissipate over the distance. If the incorrect gauge wire is used for a high-amp, long-distance conductor, the 24 volts that you started with could be reduced greatly by the time it reaches the load, not allowing the load to operate properly and compromising your system. In addition to the required components of 33
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