The Step That Gets Deferred Until the Building Official Walks In
This article is for electrical contractors, low-voltage integrators, and facility managers who are installing or commissioning a magnetic lock kit on an exterior or interior access-controlled door. The specific problem it addresses: the fire alarm interface requirement for electromagnetically locked egress doors gets treated as an afterthought on a surprising number of jobs — and it consistently surfaces as a deficiency at final inspection or annual fire door review.
If you are sourcing a kit that includes a 1200 lb magnetic lock, a weatherproof keypad, a power supply, and a push-button release, you already have most of what you need to control ingress. What the kit does not wire for you is the connection between the lock power supply and the building fire alarm system. That connection is a code requirement, not an option.
What the Code Actually Requires
Electromagnetically locked egress doors are addressed in both the International Building Code and NFPA 101. The core requirement across both documents is consistent: the magnetic lock must release automatically upon activation of the building fire alarm system, and it must also release upon loss of power to the lock itself.
- IBC Section 1010.1.9.7 (and parallel sections in earlier editions) — Electromagnetically locked egress doors must unlock on fire alarm activation, loss of power, and actuation of a listed sensor at the door.
- NFPA 101 Section 7.2.1.6.2 — Electromagnetic locks on egress doors must fail to the unlocked position on loss of power and must release on fire alarm signal.
The practical result: the power supply feeding the magnetic lock must receive a dry-contact signal or supervised relay output from the fire alarm panel. When the fire alarm activates, power to the lock drops and the door opens freely. This is not optional and it is not something the keypad or the push button handles. Those devices cover ingress credential release and manual egress release, respectively. The fire alarm interface is a separate circuit path.
Why This Gets Skipped in the Field
On most commercial projects, the access control scope and the fire alarm scope are held by different subcontractors. The low-voltage or security sub installs the magnetic lock kit, wires the keypad, runs the power supply, and confirms the door holds and releases on credential. The fire alarm sub terminates devices at the panel and closes out the fire alarm scope. Neither crew owns the bridge between the two systems unless the general contractor or the hardware consultant has explicitly called it out in the scope documents.
Common field gaps include:
- The power supply has a fire alarm input terminal that is simply left disconnected because no one was told it needed to be landed.
- The fire alarm sub does not know there is a magnetic lock in the building because it was not shown on the life-safety drawings.
- A push-button release was installed and the crew assumed that satisfied the egress requirement — it does cover the manual release requirement but does not substitute for the fire alarm interface.
- The door is in a tenant space added after the original fire alarm design, and no one pulled the fire alarm into the scope update.
How the Interface Actually Works
Magnetic lock power supplies designed for egress applications include a dedicated input for fire alarm integration. When the fire alarm panel sends a signal — typically by opening a normally closed contact or energizing a relay — the power supply interrupts current to the lock. The armature plate releases and the door is free to push open.
Key points to confirm with your specific power supply and fire alarm panel:
- Contact type: Most magnetic lock power supplies accept a dry-contact normally closed input. Confirm whether your fire alarm panel output is a dry contact, a supervised relay, or a supervised circuit — the wiring method differs.
- Supervision: Some AHJs and some fire alarm systems require the interface circuit to be supervised, meaning an open or short on the wire will trigger a fault. Check with the fire alarm sub before assuming an unsupervised loop is acceptable.
- Fail-safe confirmation: A magnetic lock is inherently fail-safe — power off equals door unlocked. Confirm the power supply is wired to drop completely on the fire alarm input, not just reduce holding force.
- Door position monitoring: Many inspectors will also ask whether the access control system monitors door position. A door position switch (DPS) wired back to the panel or controller documents that the door is not propped open after a lock release event.
Application Contexts Where This Is Most Often a Problem
The fire alarm interface gap shows up across building types, but certain project scenarios produce it more reliably than others:
- Schools and educational facilities: Exterior doors secured after hours with magnetic lock kits are common. When the security scope is handled separately from the fire alarm contractor, the interface rarely makes it into either scope of work without explicit documentation.
- Healthcare and medical office buildings: Controlled access to staff corridors and pharmacy areas often uses magnetic locks. Life-safety requirements in healthcare occupancies are among the most stringently inspected, making this gap especially consequential.
- Industrial and warehouse facilities: Employee entrance doors on weather-exposed openings frequently use weatherproof keypad kits with high-holding-force locks. Facilities managers replacing older hardware mid-lease often do not involve the fire alarm sub at all.
- Retail and mixed-use tenant spaces: Back-of-house and receiving doors added after initial tenant buildout are among the most common sources of failed access control inspections.
What to Confirm Before the AHJ Visit
Before the authority having jurisdiction walks the building for access control sign-off or the annual fire door inspection, verify the following at every electromagnetically locked egress door:
- Fire alarm interface terminal on the power supply is landed and the circuit is confirmed active.
- A manual push-button release labeled Push to Exit is installed on the egress side, mounted between 40 and 48 inches above the finished floor, within 5 feet of the door.
- The push button releases the lock for the required duration and relocks automatically after the timer expires — confirm the timer is functioning.
- Loss-of-power test: with the power supply disconnected, confirm the door swings free.
- Fire alarm simulation test: with the fire alarm sub present, trigger a test signal at the panel and confirm the lock releases at the door.
- If the door is in a fire-rated assembly, confirm the magnetic lock and any associated hardware are listed for use on fire-rated openings and that the fire alarm interface is part of the rated assembly behavior.
Hardware Considerations When Sourcing the Kit
When specifying or ordering a magnetic lock kit for an exterior or high-security interior door, the components bundled in the kit matter for how cleanly this interface can be accomplished. A kit that includes a power supply with a clearly documented fire alarm input terminal, a weatherproof keypad rated for exterior exposure, and a push-button egress release gives the installing crew everything they need — provided the fire alarm interface terminal is actually used.
DoorwaysPlus carries magnetic lock kits and access control components including power supplies, push-button release stations, door position switches, and mounting hardware for a range of door types and holding force requirements. If you are coordinating a multi-trade installation and need to confirm how a specific kit handles the fire alarm input, the team at DoorwaysPlus can help you work through the wiring sequence before the hardware ships.
For openings where a magnetic lock kit is not the right fit — or where the AHJ has concerns about electromagnetic locking on a particular occupancy type — electric strikes, electrified mortise locks, and access-controlled exit devices from lines such as Sargent, Corbin Russwin, and Accentra (formerly Yale) offer alternative approaches that may be easier to integrate with your existing fire alarm topology.
The Takeaway
A magnetic lock kit with a keypad controls who gets in. The fire alarm interface controls what happens when everyone needs to get out. Those are two different wiring tasks, and the second one does not happen automatically just because the first one was done correctly. Treat the fire alarm interface as a first-trade coordination item at the start of the project, not a punch-list item at the end — and confirm it with a witnessed test before the inspection is scheduled.