Electric strike vs maglock: how to choose for access control

How each device works

An electric strike (ANSI/BHMA A156.31) goes in the frame where the normal strike would be. The lock or exit device on the door still latches into it. When the strike is released, the keeper swings so the door can be pulled open without retracting the latch. Egress side operation is unchanged: the inside lever or exit device works as normal.

An electromagnetic lock (ANSI/BHMA A156.23) mounts at the head of the frame, with an armature plate on the door. While powered, it holds the door shut. Cut the power and the door is free. It does not latch, so it does nothing on its own to keep a fire door closed.

Fail-safe vs fail-secure

Fail-secure only means the outside stays locked. People inside can always get out through the mechanical lock or exit device. Maglocks are inherently fail-safe, since a magnet with no power holds nothing.

Fire doors must stay latched

A fire door has to positively latch during a fire. That rules out a fail-safe electric strike on a fire-rated door, because losing power would leave the door unlatched. Electric strikes on fire doors must be fail-secure and listed for fire door use, and the combination must work with the door and frame label. See fire-rated doors.

A maglock can be added to a fire door only where the door also has its own positive latching hardware and the installation is allowed by the listings and the AHJ. Never treat a maglock as the latching device on a fire door.

Maglock egress requirements

Because a maglock blocks the door until it is released, the IBC and NFPA 101 have specific rules for electrically locked egress doors. Requirements vary by code edition, but they typically include:

• A sensor on the egress side that unlocks the door when someone approaches.
• A manual release device (usually a push button signed PUSH TO EXIT) mounted 40 to 48 inches above the floor and within 5 feet of the door, which cuts power to the lock directly, independent of the access control system, and keeps the door unlocked for at least 30 seconds.
• Automatic unlocking on loss of power and on activation of the fire alarm or sprinkler system.

An alternative arrangement allows a maglock released by a switch in the door's own lever or exit device. Each path has its own conditions, and section numbers move between code editions, so look for the sensor release and door hardware release provisions by name. Systems are typically required to be listed to UL 294. On doors that require panic hardware, maglocks are allowed only under narrow conditions that have changed between editions. Confirm the exact requirements in the adopted code and with the AHJ before specifying a maglock on any egress door.

Electrified locks and getting power to the door

Strikes and maglocks are not the only choices. Electrified locksets (mortise or cylindrical) lock and unlock the outside lever and come fail-safe or fail-secure. Electric latch retraction exit devices pull the latch in for push/pull or automatic operator doors. Both put the power in the door, which needs a path from the frame:

• Electric hinge with wires through the hinge.
• Concealed electric power transfer in the hinge edge.
• Exposed armored door loop.

Strikes and maglocks are frame-mounted, so they skip the transfer but need frame prep and coordination with the hollow metal frame order. List power supplies, request-to-exit devices and door position switches in the hardware set so nothing falls between Division 08 and the security contractor.