The electromagnetic lock is a lock with two main components: an armature mounted on the door and a magnetic lock assembly mounted on the frame. Electromagnetic locks are often referred to as magnetic locks, or even just "Mag Locks". These locks are electric and are typically connected to an access control system and receive signals from other hardware, such as motion sensors, to request an exit switch or credential reader. These are usually paired with an outlet device with a built-in signal switch connected to a magnetic lock.
The magnetic lock provides fault safety, which means that when the power supply is cut off, the device will remain unlocked, which also means that the magnetic lock can remain locked only when the power supply is continuous.
The electromagnetic lock usually provides 12 or 24V options, which can be selected on site. Some magnetic locks allow AC or DC power. Once engaged, many magnetic locks will keep the door safe with hundreds of pounds of retention force. Some positions may have higher retention force than others.
Magnetic locks can be used on fire openings as long as they are tied to the fire alarm system and programmed to disengage when the alarm is activated. This allows free egress in case of power failure. NOTE: These locks do not replace the locking hardware required for fire resistant openings.
The lower safety door can have a magnetic lock with a retention force of 500 to 1000 pounds. It is also an ideal choice for indoor wooden doors and aluminum doors. Higher safety doors can weigh 1000 to 3000 pounds. It is recommended to use retention on larger hollow metal doors and frames.