Electromagnetic locks were introduce in the U.S in the 1970’s and continue to be popular today. They are used to secure emergency exit doors and when connected to a fire alarm system, the locks power source automatically disconnects when the fire alarm is activated to allow people inside to exit quickly.
The operation of an electromagnetic lock is different from that of a conventional locking device. Unlike a mechanical lock, an electromagnetic lock does not rely on the release of a bolt or latch for security. It instead uses electricity and magnetism. It is the magnetic power of these locks that tend to make them stronger than their mechanical counterparts and because the components of an electromagnetic lock are normally installed inside the door and casing, as opposed to being mounted on the outside of the door as is usually the case with mechanical locks, the screws can not be tampered with when the door is in the closed position.
Standard electromagnetic locks consist of two components in order to secure a door. The first component being a electromagnet and the second being a metal strike plate. The electromagnet is installed in the doors header and the strike plate is installed on the door. When a door is closed the two components line up. The electromagnet is usually powered by 12 to 24 dc volts at 3 to 8 watts and when the door is closed and the electromagnet is powered, the door is secured and has a holding power of 300 to 3000 pounds, depending on the type of electromagnet lock you selected.
So what if the power goes out or a burglar cuts the wires?
Standby batteries are usually installed with the lock to provide power in the event the power goes out. The locks can’t be tampered with from the outside the door as all the components are installed completely inside the door itself. Thus eliminating the chance that a would be burglar could cut wires or gain entry through the door.
Fire code requirements for Electromagnetic locks.
Electromagnetic locks meet the safety requirements of the North American building codes because they are fail-safe, which means when there is no power to the door, the door will not lock. In order to comply with most United States building fire codes, there is also a couple of additional pieces of hardware that must be installed when installing electromagnetic locks. There must be a “PUSH TO EXIT” release button and either a PIR motion detector or an electrified exit release bar also known as a crash bar. Also if the building has a fire alarm system the electromagnetic locks must be tied into the fire control system so the locks will automatically unlock in the event of a fire. The code states “There must be a minimum of two devices used to release the electromagnetic lock. One device Must be a manual release button that has the words”PUSH TO EXIT” labeled. This push button must provide a 30 second time delay when pushed, and the time delay must act independently of the access control system (the delay must work on its own, not tied into any other access control system)
The downsides of Electromagnetic locks
Electromagnetic locks do have a couple of disadvantages. One is the cost of the electromagnetic locks when compared to other high security mechanical locks. Electromagnetic locks can cost four to ten times more than a mechanical lock. The second downside is that many people find the electromagnetic locks less attractive than conventional mechanical locks.
I hope you have found this article helpful when considering electromagnetic locks.
We though you’d like to know….
Stay safe Citrus county!