Most types of latching hardware – including electromechanical locks – allow free egress in a similar fashion to standard mechanical hardware; turn the lever or push the touchpad, and the latch retracts. Electromagnetic locks do not function this way, so additional release devices are required in order to allow building occupants to exit by removing power from the mag-lock to break the electromagnetic bond.
The model codes address two different applications for electromagnetic locks – those released by a sensor which detects a building occupant approaching the door, and those that are released by a switch in the door-mounted hardware. The egress requirements for each of these applications vary, so it’s important to identify which application is being used for a particular installation, in order to identify which set of code requirements to apply.
One point of confusion has been the model codes’ use of the terminology, “Access-Controlled Egress Doors” when describing electromagnetic locks released by a sensor. In some cases this has led to the interpretation that these code sections applied to all doors equipped with access-control readers. Since most doors that are part of an access control system allow free egress, the intent of the model codes is not to apply these requirements to all doors with access-control readers. This section applies only to doors with electrified locks released by a sensor; in fact, the applicable section titles for the sections addressing mag-locks in both the International Building Code (IBC) and NFPA 101 – Life Safety Code have been changed within the last few editions to avoid further confusion:
- IBC – ‘Sensor Release of Electrically Locked Egress Doors’ and ‘Door Hardware Release of Electrically Locked Egress Doors’
- NFPA 101 – ‘Sensor-Release of Electrical Locking Systems‘ and ‘Door Hardware Release of Electrically Locked Egress Door Assemblies’
View the video and/or check out this Decoded article to learn about the requirements that apply to electromagnetic locks, and then proceed to the review questions below.
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Review Questions
1. A door with an electromagnetic lock released immediately by a building occupant pushing a sensor push bar mounted on the door must comply with which of the following IBC sections?
- Access controlled egress doors
- Delayed egress locks
- Controlled egress locks
- Door hardware release of electrically locked egress doors
2. Which of the following is NOT required by the IBC for an electromagnetic lock that is released by a sensor detecting an approaching occupant?
- Unlock upon fire alarm
- Unlock upon power failure
- Unlock via push button beside the door
- Unlock 15 seconds after an attempt to exit
3. Which of the following is required by the IBC for an electromagnetic lock that is released by a switch in door-mounted hardware?
- Unlock upon fire alarm
- Unlock upon power failure
- Unlock via push button beside the door
- Unlock 15 seconds after an attempt to exit
Answers: 1 – D, 2 – D, 3 – B