A magnetic lock is a magnet that is created when an electrical current is passed through a wire with multiple coils around an iron core, or a solenoid (single coiled wire wrapped around a metal core). When the electrical current is disrupted the metal wire is no longer magnetized. Because of the very nature of an electromagnet, it can not be fail-secure, which means that in the result of an emergency or power outage, the doors will unlock. The built-in feature of unlocking in the result of a power outage (referred to as fail-safe) is the basic operating premise of the electromagnet or maglock.
When there is no emergency or power failure to disable the locks, the magnets can be manipulated with a push-button, keypad, or card reader that temporarily interrupts the electrical current. After a few seconds, the current will return, and once the door has closed it will magnetically bind the door to the door frame. This lock set up is constructed by fixing a plate of magnetic metal (usually iron) to the door, and the electromagnet to the door frame.
- The lock will open in the case of an emergency (fail-safe).
- The lock can be made to open with any electrical signaling method (key code, swipe card, motion sensor, biometrics, etc.)
- Electromagnets are available with a large selection of holding force options. Commonly, from 600 pounds to 1,200 pounds or more of holding force.
- The security can be overcome by interrupting the electricity in the building (referred to as fail-safe).
- The door may be able to be pried open depending on the gap between the door and frame (force required is based on the magnetic lock holding force).