Electrically Locked Egress Doors and the Maglock Rules

Why this matters

A maglock holds a door shut with nothing a person on the inside can turn, push or pull. On a door people use to get out of a building, that makes it the one access-control device that can trap someone in a fire, and it is the device inspectors look at hardest. A maglock wired the way it is usually wired for convenience, with the exit button as a signal into the controller, fails inspection, gets torn out at the dealer's cost, and in the worst case holds a door during an evacuation. This card is the rule set a sensor-release maglock door has to meet, what each rule is protecting against, and how to wire it so every condition is met by hardware rather than by software.

For choosing between a strike and a maglock in the first place, see related: Electronic Strike vs Maglock, Fail-Safe vs Fail-Secure Selection.

Why a maglock is a special case

The building codes start from one principle: a door in the means of egress opens from the egress side without a key, special knowledge or special effort. A lever, a panic bar or a thumb turn meets that. A maglock does not, because its holding force has no mechanical release on the door at all. The only way out is to remove its power.

So the codes allow an electrically locked egress door only under specific provisions that guarantee power comes off when someone needs out. The International Building Code (IBC) carries several in Section 1010: sensor release, door hardware release, delayed egress and controlled egress for certain care occupancies. A maglock with a motion sensor and a push-to-exit button is the sensor release arrangement. Its subsection number has moved within Section 1010 between editions, so find it by name in the edition you work under. The IBC binds you only as your state or city has adopted it, in the edition they adopted, and some jurisdictions amend it. Where the NFPA 101 Life Safety Code is also adopted (common in healthcare, schools and state-regulated occupancies), its access-controlled egress provision in Section 7.2.1.6 applies alongside, in the edition adopted.

The door hardware release option matters because it is often the easier answer: an electrified lock where operating the door's own lever or panic bar mechanically frees the door, with no sensor rules at all. A fail-secure strike paired with a mechanical lever gives the same free egress. A maglock is the right device when the door cannot take a strike or the owner wants no latch, and it brings every condition below with it.

The sensor-release conditions, in substance

Paraphrased from the IBC sensor-release provision; check the wording and numbering in the edition your jurisdiction adopted, and confirm the occupancies it is permitted in.

1. A sensor on the egress side detects an occupant approaching the door and unlocks it. In practice a motion request-to-exit (REX) sensor mounted above the door, aimed down at the approach.
2. Loss of power to that sensor unlocks the door. A sensor that dies quietly must not leave the door locked.
3. A manual unlocking device, the push-to-exit button, mounted 40 to 48 inches above the floor and within 5 feet of the door, readily accessible and clearly marked "PUSH TO EXIT". Operating it must interrupt power to the lock directly, independent of the access control electronics, and the door stays unlocked for at least 30 seconds.
4. Activation of the building fire alarm or sprinkler system, where the building has one, unlocks the door, and it stays unlocked until the fire alarm system is reset.
5. Loss of power to the lock or locking system unlocks the door.
6. Entrance doors in assembly, business, educational and mercantile occupancies (Groups A, B, E and M) are not secured from the egress side while the building is open to the public.

Recent editions also require the locking system to be listed, with UL 294 named for access control systems; check whether your adopted edition carries that and buy hardware accordingly.

Condition 3 is the one installers miss. A button wired only as an input to the controller depends on the controller's firmware, its relay and its power supply to release the door. The code wants the button to work when all of that has failed, so its contacts sit in the lock's own power path.

How the hardware meets each condition

EGRESS SIDE (inside looking out)

        [ REX MOTION SENSOR, aimed down at approach ]
  +==[ MAGLOCK on frame head ]===============+
  |  [ armature plate on door ]   |          |
  |                               |  [PUSH   |
  |        DOOR LEAF              |   TO     |
  |                               |   EXIT]  | button
  |                               |          | 44 in AFF
  +-------------------------------+----------+ 18 in from
  FLOOR                                        frame

LOCK POWER PATH, every contact in series:
 PSU + --> fire alarm relay  (closed; opens on alarm)
       --> PUSH TO EXIT      (closed; opens for 30 s+)
       --> REX sensor relay  (closed when powered; opens
                              on motion or power loss)
       --> controller relay  (closed; opens on badge)
       --> MAGLOCK coil --> PSU -

Opening any one contact drops the coil and releases the door. Read the path against the conditions:

• Condition 1 and 2. The REX sensor's relay is energized in the normal state and held closed. Motion de-energizes it, and so does losing its own power. Wire the sensor's contact that is closed when energized, so both events open the lock path. Wired to the opposite contact, a dead sensor holds the door locked, which is exactly what the condition forbids.
• Condition 3. The button is a timed device whose normally closed contacts open the lock path directly and stay open for the set time. A button with a built-in adjustable timer, or a button driving a separate time-delay module in the power path, both work. A momentary button into a controller input does not.
• Condition 4. A relay in the fire alarm control unit, supervised and programmed by whoever holds the fire alarm license, opens the lock path on alarm and holds it open until reset. That tie is fire alarm work. The dealer lands the lock side; the fire alarm contractor provides and programs the relay. See related: What a Fire Alarm Panel Is Actually Doing.
• Condition 5. A maglock releases on loss of power by nature. A power supply with standby batteries keeps it locked through a utility outage. Many AHJs accept that as long as the fire alarm release still works on battery; others read the condition as loss of utility power and want the door to release. Ask before you specify batteries.

Maglocks generate a voltage spike when their coil drops. Most carry built-in suppression; where the maker calls for a diode or varistor across the coil, fit it at the lock, or the spike walks back through the button and relay contacts and pits them.

Worked example: a second-floor office stair door

A dental office wants its rear stair door locked from the stair side and badge-controlled, no latch hardware, and the building has a monitored fire alarm. The door swings into the stairwell, egress direction. Before ordering anything, the dealer calls the building department with the door, the occupancy and the hardware list. The plan reviewer confirms the sensor-release provision applies in that occupancy under the adopted edition and asks for the fire alarm release.

Layout. Maglock on the frame head on the office side, the side the door swings away from, with the armature on the door's office face, so any force opening the door pulls the armature straight off the magnet; this is a rear stair door, not the office entrance, so condition 6 does not reach it. REX motion sensor centered above the door on the office side, aimed so a person reaches its pattern about 3 feet from the door. Push-to-exit button on the office side wall, latch side, at 44 inches above the finished floor (inside the 40 to 48 inch window, with 4 inches of margin either way) and 18 inches from the frame edge (well inside the 5 foot limit). Sign above it reading PUSH TO EXIT.

Timer. The button's timer is set to 35 seconds. Setting it to exactly 30 leaves the door one dial tolerance away from a fail; the stopwatch reading on test is what counts, not the dial.

Fire alarm tie. The fire alarm contractor schedules a visit, puts the fire account on test with their central station, programs a spare relay to operate on any alarm, and runs the supervised circuit to the lock power supply's fire input. The dealer is on site for that test. After the release is proven, the fire contractor confirms the station received the alarm and takes the fire account off test.

Inspection test, as recorded:

• REX: walk toward the door from three directions; release each time before the hand reaches the door.
• Sensor power removed at its terminals: door released, and stayed released until power restored.
• Button pressed, controller powered off first to prove independence: door released, stopwatch read 34 seconds to relock.
• Fire alarm initiated by the fire contractor: door released; held released after the alarm was silenced; relocked only after the fire panel was reset.
• Lock power supply AC removed: door stayed locked on standby battery for the outage test, released on fire alarm while on battery. The inspector accepted that.

Every condition was proven by an act, not by reading the wiring.

What fails inspection in the field

• The button is a controller input. It releases the door every time on the bench and fails the day the controller locks up. The inspector asks you to power the controller off and press the button.
• The timer runs short. Many buttons default to a short pulse. A door that relocks at 3 seconds catches an occupant with a cart or a wheelchair.
• The button is in the wrong place. Behind the door swing, on the hinge side where the open leaf hides it, above 48 inches, or more than 5 feet away.
• The REX sensor is aimed at the door, not the approach. A person who stops at the door to look through the glass falls out of the pattern and the lock re-engages under their hand. Aim at the approach and set the hold time long enough to cover reaching for the door.
• The REX is wired to the wrong contact, so a dead sensor holds the door.
• No fire alarm release in a building that has a fire alarm. Often the alarm contractor was never told.
• No sign, or a sign that reads EXIT instead of the required wording.
• Delayed egress features mixed in. A 15-second nuisance delay with a local alarm is a different provision with its own rules; it cannot be added to a sensor-release door by programming.

Where the answer changes

A labeled fire door. Any hardware added to a fire-rated door or frame has to be compatible with its listing. Some maglocks are listed for fire doors and some frames can take them; drilling a labeled frame or door outside its listing voids the label. Route to the door's listing and the AHJ.

Stairwell re-entry. Some codes require stair doors in multi-story buildings to allow re-entry from the stair side or to unlock on fire alarm so people can leave a smoke-filled stair. That can drive the choice of lock and the fire alarm sequence. Ask.

Licensing. Low-voltage access control licensing, fire alarm licensing and any 120 V circuit for the power supply all vary by state and city. The 120 V outlet or junction box for the power supply goes to an electrician where local rules require it. See related: Alarm and Low-Voltage Licensing Varies by State and City.

References

• International Building Code, Section 1010 (the electrically locked egress provisions, including sensor release), as adopted and amended by your jurisdiction; check the current edition
• NFPA 101 Life Safety Code, Section 7.2.1.6, access-controlled egress door assemblies, in the edition adopted where it applies
• UL 294, access control system units, where the adopted edition requires listing
• See related: Electronic Strike vs Maglock, Fail-Safe vs Fail-Secure Selection
• See related: How to Install a Maglock with Request to Exit and Fire Release