This article was published in the February 2012 issue of the Locksmith Ledger:
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.
With the addition of Section 1008.1.9.8 – Electromagnetically Locked Egress Doors, the door-mounted release device can be used instead of the sensor and emergency push button. Note that this section does not require the mag-lock to release upon activation of the fire alarm or sprinkler system when a door-mounted release device is used. But there are a few issues that are still unclear, even with the 2012 changes.
- The door must unlock upon loss of power to the “listed hardware,” which in this case is the door-mounted release device. Loss of power to some types of request-to-exit switches will not unlock the mag-lock. We may see a future change to the language so that loss of power to the electromagnetic lock is required to unlock the door, but the code currently addresses the release device.
- I-2 occupancies (Institutional – Hospitals & Nursing Homes*) are not included as acceptable locations for electromagnetically locked egress doors. This use group was added to the Access-Controlled Egress Doors section in the 2009 edition of the IBC, so hopefully the new section will catch up and include the I-2 use group in the future.
- UL 305, the UL Standard for Panic Hardware, doesn’t address the use of panic hardware to release an electromagnetic lock. There is also a section of the IBC which states that certain doors shall not be equipped with a latch or lock unless it’s panic hardware. This should be changed to reflect the use of a mag-lock released by panic hardware.
For jurisdictions using NFPA 101 – The Life Safety Code, a new section was added in the 2009 edition – 18.104.22.168.5 Electrically Controlled Egress Door Assemblies. The requirements are basically the same as the IBC, but there is no limitation on occupancy types and no restriction related to panic hardware. Keep in mind that state or local requirements could differ from those of the IBC or NFPA 101, so it’s important to be aware of the codes in your project’s jurisdiction. Refer to the published codes for the detailed code requirements, and consult the Authority Having Jurisdiction for more information about the local codes.
*Refer to Chapter 3 of the International Building Code for a complete description of these use groups.