What This Article Covers
A self-contained magnetic lock kit — one that bundles the lock body, a request-to-exit station, a weatherproof keypad, and a plug-in power supply — looks straightforward on the product sheet. Everything ships in one box. The wiring diagram fits on a single page. But the job-site failures that inspectors flag on panel-free mag lock installs almost never come from the lock itself. They come from how the egress path is sequenced through the keypad output, and from decisions that got made — or skipped — before the first wire was landed.
This guide is for commercial subcontractors, facility maintenance teams, and small-project architects who are deploying a compact mag lock kit on an interior or lightly controlled exterior door and want to understand the wiring logic, the egress compliance requirements, and where the install typically goes wrong before the authority having jurisdiction (AHJ) ever walks the job.
What Is a Self-Contained Mag Lock Kit?
A self-contained magnetic lock kit is a complete single-door access control package that does not require a separate access control panel. The kit typically includes:
- An electromagnetic lock body (rated holding force varies by model — 600 lb or 1200 lb are common)
- A request-to-exit (REX) station — a push button mounted on the interior side that interrupts lock power for egress
- A digital keypad for credential entry on the secure side
- A UL-listed plug-in power supply sized to the lock
The appeal is real: no panel programming, no panel procurement lead time, and a wiring diagram short enough to follow without an access control integrator on site. These kits are widely used in small commercial offices, school storage rooms, healthcare utility corridors, retail back-of-house doors, and light industrial personnel access points.
The limitation is equally real: every egress and fire alarm compliance requirement that applies to a full panel-controlled mag lock also applies here. The simpler hardware does not simplify the code.
How the Wiring Path Actually Works
Understanding why mistakes happen starts with understanding what the wiring actually does. In a typical single-door mag lock kit, the power supply feeds positive and negative DC voltage into the keypad's terminal strip. The magnetic lock connects through the keypad's output relay. The REX button connects to a separate input or to the normally-open contacts of that same relay.
The key principle: each egress device in the chain works by interrupting or bypassing the power path to the lock. When a valid code is entered on the keypad, the relay drops the lock. When the REX button is pressed, it similarly interrupts power or triggers the relay. The lock de-energizes and the door is free.
That makes this a fail-safe system by design — loss of power drops the lock and allows egress. That is the correct configuration for a mag lock on an egress door. Fail-secure behavior (lock stays locked on power loss) is not permitted on egress-required openings.
The Wiring Step That Gets Skipped Most Often
On jobs where the mag lock kit is installed by an electrician or a door hardware sub who does not regularly work with access control, one component gets skipped more than any other: the fire alarm interface.
IBC Section 1010.1.9.7 and NFPA 101 Section 7.2.1.6.2 both require that electromagnetic locks on egress doors release upon activation of the building fire alarm system. A self-contained mag lock kit does not automatically provide this interface — it must be wired in. If the building has a fire alarm panel, that panel needs to interrupt power to the lock (or trigger the lock's release input) when an alarm is activated.
On small projects — a single storage room in a school, a server room in a medical office building — it is easy to assume the fire alarm connection is someone else's scope. It often ends up in no one's scope until the inspector asks for the sequence of operations documentation.
What the AHJ Will Ask About
- Does the lock release on fire alarm activation?
- Does the lock release on loss of power (fail-safe confirmation)?
- Is the egress release (REX button) accessible from the egress side without special knowledge or tools?
- Does the REX button require only one motion to release — no codes, no keys?
- If the door is on a required egress path, is a sensor or listed switch in the hardware used for release, or is a separate push button required?
Most kit installations satisfy the last few points by default — the REX station is designed for one-press release. The fire alarm interface is the gap that causes re-inspection.
Motion Sensor REX vs. Push Button REX: When It Matters
Some mag lock kits are available in a variant that adds a passive infrared (PIR) motion sensor — sometimes called an active request-to-exit sensor — to the standard push button REX. The motion sensor detects an occupant approaching the door from the interior and releases the lock automatically, without the occupant having to press anything.
This configuration is common in:
- Healthcare facilities — where staff pushing a cart or gurney cannot easily reach a push button
- Industrial settings — where workers may have full hands when exiting through a controlled door
- ADA-sensitive applications — where hands-free egress reduces barriers for mobility-impaired occupants
The tradeoff is sensitivity adjustment. A PIR sensor that is too sensitive will release the lock every time someone walks past the door on the inside. A sensor that is too conservative may not trigger in time. Field adjustment of sensitivity and range is part of commissioning, not part of rough-in — but that step is regularly skipped.
When specifying a kit for healthcare or school corridor applications, confirm whether the PIR variant is required by the project's sequence of operations before ordering. Adding it later is a second trip and a second order.
Mounting Height and Armature Plate Alignment
The magnetic lock body mounts in or above the frame header. The armature plate mounts on the door face at the top rail. When power is applied, the armature plate is drawn tightly to the lock face and held. When power is removed, the door is free.
The detail that causes callbacks on mag lock kit installs is armature plate alignment. If the armature plate is not flush and parallel to the lock face — even a small gap or angle — the holding force drops significantly. A 1200 lb rated lock with a poorly aligned armature may hold at a fraction of its rated force.
- Check armature plate flatness against the lock face with power applied before finalizing fasteners
- Confirm the door is in its normal closed and latched position (if a latch is present) before setting the armature
- On hollow metal frames, verify the header is rigid enough to hold the lock body without flex under load
Kit vs. Component Build: Which Job Gets Which Approach
A self-contained mag lock kit is the right tool when:
- The project involves one or two controlled doors not connected to a central access control system
- There is no panel budget or panel infrastructure on site
- The credential requirement is simple — a shared code, no audit trail, no card credential
- The timeline is short and procurement needs to move fast
When the project grows to three or more doors, requires individual user credentials, or needs audit trail reporting, the kit's keypad becomes a limitation rather than a convenience. At that point, a panel-based system with separately specified locks, REX devices, and power supplies is the right architecture — and the wiring diagram grows accordingly.
DoorwaysPlus carries mag lock kits, standalone electromagnetic locks, request-to-exit stations, and weatherproof keypads. If your project is on the line between kit and component build, the right starting point is confirming the door count, the credential type, and whether the fire alarm interface is already scoped before anything ships.
Final Checklist Before Commissioning a Mag Lock Kit
- Fail-safe confirmed: Lock drops on power loss — verify by pulling supply power with the door closed
- REX station wired and tested: Single press releases lock from egress side with no code required
- Fire alarm interface connected: Building FA panel interrupts lock power on alarm activation
- Armature plate aligned: Flush, parallel, no gap visible with lock energized
- PIR motion sensor adjusted (if installed): Sensitivity and range set to release before occupant contacts door
- Power supply load verified: Supply is sized to the lock — do not share supply with unrelated loads
- Sequence of operations documented: One-page diagram showing every release condition, available for AHJ review