An electromagnetic lock is essentially an electromagnet in a housing mounted on the door frame, and a steel armature mounted on the door. When the magnet is energized, it bonds to the armature and locks the door. To allow access or egress, a switch must be provided to de-energize the magnet.
Prior to the 2009 edition of the International Building Code (IBC), the set of code requirements typically used for doors equipped with electromagnetic locks was the section called Access-Controlled Egress Doors. The 2009 edition added a second set of requirements that could be used, called Electromagnetically Locked Egress Doors. Either of these two sets of requirements can now be used, depending on the application.
The basic difference between these two sections is that the original section, Access-Controlled Egress Doors, required a sensor and push button as release devices, while the new section, Electromagnetically Locked Egress Doors, allows a door-mounted release device instead. This could be panic hardware or a latchset with a request-to-exit (RX) switch, or a bar with an electronic touch sensor.
Here is a summary of the requirements for both sections from the 2009 IBC:
1008.1.4.4 Access-Controlled Egress Doors
- Applies to entrance doors in a means of egress and entrance doors to tenant spaces.
- Allowed in Use Groups - A (Assembly), B (Business), E (Educational), I-2 (Institutional - Hospitals & Nursing Homes*), M (Mercantile), R-1 (Residential - Hotels, Motels, & Boarding Houses*), and R-2 (Residential - Apartments & Dormitories*).
- A sensor must be mounted on the egress side to detect an occupant approaching the doors. Doors must unlock upon a signal from the sensor or loss of power to the sensor.
- Loss of power to the lock must unlock the doors.
- A manual unlocking device (push button) shall result in direct interruption of power to the lock – independent of the access control system electronics. When the push button is actuated, the doors must remain unlocked for 30 seconds minimum. The push button must include signage stating “Push to Exit” and must be located 40” to 48” vertically above the floor and within 5’ of the doors. Ready access must be provided to the push button.
- If the building has a fire alarm/sprinkler system/fire detection system, activation of the system must automatically unlock the doors. Doors must remain unlocked until the system has been reset.
- Entrance doors in buildings with an occupancy in Group A, B, E or M shall not be secured from the egress side during periods that the building is open to the general public.
1008.1.9.8 Electromagnetically Locked Egress Doors
- Applies to doors in a means of egress and doors to tenant spaces. The 2009 IBC includes a limitation to doors “not otherwise required to have panic hardware,” which was removed in the 2012 edition.
- Allowed in Use Groups - A (Assembly), B (Business), E (Educational), M (Mercantile), R-1 (Residential - Hotels, Motels, & Boarding Houses*), and R-2 (Residential - Apartments & Dormitories*).
- The door must be equipped with listed hardware mounted on the door leaf, which incorporates a built-in switch to directly release the electromagnetic lock and unlock the door immediately.
- The release device must have an obvious method of operation, and must be readily operated with one hand under all lighting conditions.
- Loss of power to the listed hardware must automatically unlock the door.
When the new section was added to the 2009 IBC, the technical committee made a change to the proposed language which caused some confusion. A limitation to doors that are “not otherwise required to have panic hardware” was included in the 2009 edition, but it appears that this was not the intent. The limitation was removed and the intent clarified in the 2012 edition of the IBC, and as long as the switch in the panic bar releases the mag-lock, a door required to have panic hardware can be equipped with a mag-lock.
Maglocks are relatively inexpensive, work many door and gate types, have no moving parts and are reliable and cost effective.
The most-asked question is: “Where does it say I can’t drill a hole in a fire door?”
Important: Before installing electronic locks, it is important to check with the “Local Authority Having Jurisdiction” (LAHJ). An electromagnetic lock is designed to provide security for a...