Electronic Door Hardware
Access control software decides whether a credential is valid. Electronic door hardware physically holds the opening shut and lets go on command: the half of the system bolted to a moving door, with a life measured in cycles, governed by fire and egress code, unfixable from a keyboard. This page stays at the opening: leaf, frame, latch, release and the power reaching it. Deciding who is standing outside is on intercom and entry systems. A powered vehicle gate follows UL 325 and a different rulebook, on gate and vehicle access.
The survey is mechanical before it is electrical
Before any part number is chosen, the opening is measured as millwork. Handing, frame material and depth, latch type, hinge wear, closer condition and how squarely the door sits narrow the options. A hollow metal frame accepts preparations an aluminum stile-and-rail entrance does not, and a door dropped on worn hinges misaligns a strike keeper whatever is specified.
Preload is the failure people rarely predict. Weatherstripping, closer force and building pressure can press a latchbolt into the keeper hard enough that a strike will not release, which is why electric strikes carry a preload rating. In tall Chicago buildings, winter stack pressure makes this seasonal: doors that release fine in July and refuse in January. Along the Gulf, humidity swells wood doors and corrodes exterior trim, shortening the service interval more than the specification.
Fail-safe or fail-secure is decided opening by opening
A fail-safe device unlocks when power is removed. A fail-secure device stays locked, egress provided mechanically by the lever or exit device. Neither is inherently correct. A stairwell re-entry door, a server room and a main entrance can land on three different answers in one building, so the decision belongs in an opening schedule, not a blanket instruction.
Magnetic locks are always fail-safe, since holding force comes from the current, and they provide no latch at all, which drives most of the code questions that follow.
Egress code sets the boundaries
Electrically locked egress doors released by a sensor generally require the sensor on the egress side, release on power loss and on fire alarm, and a labeled manual unlocking device near the door cutting power to the lock for at least 30 seconds regardless of the access system. Delayed egress has its own conditions: irreversible release after 15 seconds, or 30 where the authority having jurisdiction permits, plus signage and alarm.
Local interpretation varies more than the printed code does. Officials in Chicago, Houston, St. Louis and Kansas City each have habits about what passes on a given opening, and asking first beats a failed inspection with doors hung.
Fire-rated openings narrow the list quickly
A fire door assembly has to be self-closing and positive-latching. A maglock cannot supply that latching, ruling it out on a rated opening. Strikes on fire doors must be fail-secure and listed for fire door use. Field modification of a labeled door or frame is restricted, so cutting a preparation the listing does not allow voids the label on an assembly compliant that morning.
Getting power and a true exit signal to a moving leaf
- Power transfer. An electric hinge, a concealed frame transfer or an armored cord carries conductors across the gap. Count them first: lock power, latch monitoring and a request-to-exit signal may all cross.
- Voltage drop. A long low-voltage run can leave a lock chattering or a strike buzzing. Gauge and length are calculated, never guessed.
- Inrush versus holding. Electric latch retraction draws far more current retracting than holding, so it belongs on a supply with a latch retraction module, not a shared general-purpose panel.
- Request to exit. A switch inside the exit device or lever reports that someone is actually leaving. A motion sensor above the door only shunts the contact so no alarm sounds, and does not unlock a fail-secure device. Confusing the two is a common and consequential error.
Wireless and battery-powered locks have a lane
Battery locks solve pathway problems on interior doors where running conductors is disruptive. The trade is communication interval and revocation latency, plus a battery routine somebody owns. Where a credential must stop working immediately at a perimeter opening, wired hardware remains the answer.
What we hand back is an opening-by-opening schedule: number, function, hardware, fail state, power source, monitoring points and test result. Send drawings, photographs and existing hardware model numbers. Call (888) 360-0035, or reach headquarters at 6201 Fairview Rd, Charlotte NC 28210.