What This Article Covers -- and Who It Helps
Asylum function mortise locksets appear on hardware schedules for behavioral health units, psychiatric wards, memory care wings, and secured patient corridors -- and they get misspecified or miswired more often than most designers expect. This guide explains exactly what asylum function means, how it differs from other institutional lock functions, where it is code-permitted, and what the electrified version requires before the access control contractor touches a wire. It is written for healthcare construction managers, commercial hardware specifiers, and facility directors planning a renovation or new build.
What Is Asylum Function on a Mortise Lockset?
Asylum function -- identified as ANSI F30 in the BHMA standards and commonly called Function 17 in mortise lock nomenclature -- is a double-cylinder institutional lock in which both levers are rigid at all times. Neither side operates the latch by lever. The latch retracts only when a key is inserted and turned from either side.
That is the critical distinction from nearly every other function on a hardware schedule:
- Storeroom (F07): Outside always locked; inside lever always free. Egress is unrestricted.
- Classroom (F04): Outside locked by key; inside lever always free.
- Asylum (F30): Both sides locked. Always. Key required for entry and exit. Egress is controlled.
That last point is what makes asylum function a life-safety decision, not just a hardware selection.
Where Asylum Function Is Code-Permitted
Because asylum function restricts egress, it is not a general-purpose commercial lock. Its use is tightly bounded by the International Building Code and NFPA 101 Life Safety Code.
I-2 Occupancy -- The Primary Application
The primary code home for asylum function hardware is IBC I-2 occupancy -- hospitals, nursing homes, behavioral health facilities, and memory care units where occupants require supervision or restraint for their own safety. In these environments, controlled egress is an acknowledged life-safety strategy, not a violation of it.
Both IBC and NFPA 101 permit special locking arrangements in I-2 occupancies provided specific conditions are met, including:
- Staff are in continuous attendance in the area.
- Locks release automatically on fire alarm activation (or are releasable by staff at a continuously attended location).
- The arrangement is approved by the Authority Having Jurisdiction (AHJ).
Projects involving asylum function hardware should be escalated to the design team and AHJ early -- this is not a field decision.
Where It Does Not Belong
Asylum function is not appropriate for standard commercial offices, schools, retail, or industrial applications. Specifying it on any opening used for general means of egress outside an approved I-2 controlled-egress plan creates a life-safety violation. If you see asylum function on a hardware schedule for a door that does not serve a secured patient or resident area, flag it before ordering.
Mechanical vs. Electrified Asylum Function
Mechanical (Standard) Asylum Mortise Lock
The mechanical version operates entirely by key. Both levers are dead -- no button, no thumbturn, no toggle. A properly keyed staff member inserts the cylinder and retracts the latch. The auxiliary deadlatch is present to resist shimming and latchbolt manipulation. Door prep is standard mortise (ANSI A115.1 Type 86 cutout, 2-3/4 inch backset on most 1-3/4 inch doors).
Preferred lines for mechanical asylum mortise locksets include Sargent (8200 Series Function 17, 9200 Series Function 17F), Corbin Russwin (ML2000 Series), and Hager -- all available through DoorwaysPlus.com.
Electrified Asylum Mortise Lock
The electrified asylum function lock adds a solenoid or motorized actuator that can retract the latch on a signal from the access control system -- typically a nursing station panel, credential reader, or building automation event. Both levers remain rigid; the electrical signal does the work of a key.
Key electrical details to confirm before the access control contractor arrives:
- Fail-safe vs. fail-secure: Fail-safe (power loss = latch retracts, door openable) is the typical requirement in I-2 occupancies so that a fire alarm or power failure does not trap patients. Fail-secure (power loss = latch stays engaged) may be used in specific containment contexts with AHJ approval.
- Voltage: Most electrified asylum mortise locks operate on 12VDC or 24VDC regulated. Confirm the supply voltage and wire gauge for the run length -- voltage drop is a real concern on 100-foot-plus runs common in patient wing corridors.
- Current draw: A typical electrified asylum lock draws approximately 0.42A at 24VDC. Account for this in the power supply sizing calculation alongside readers, door position switches, and nursing station panels.
- ElectroLynx / wiring pathway: If the lock is powered through an electrified hinge (McKinney QC8 or equivalent), confirm the circuit count. Most standard electrified asylum functions require a QC8 hinge; monitoring options or motorized latch retraction may require QC12.
- Nursing station override: Many I-2 projects require a hardwired override at a continuously attended station. Confirm this is in the Division 28 scope and that the hardware set reflects it.
The Specification Detail That Gets Dropped
The most common error on healthcare hardware schedules involving asylum function is treating the lock as a standalone item without coordinating the full controlled-egress system. Asylum function hardware works as a system:
- The lock itself (mechanical or electrified asylum mortise)
- The door position switch (monitoring whether the door is open or closed)
- The release signal source (nursing station, fire alarm interface, access control panel)
- The power supply and wiring pathway
- AHJ approval of the controlled-egress plan
Ordering the lockset without confirming the release pathway and fire alarm interface is the single step most likely to cause a failed inspection or a last-minute field change.
Sourcing Asylum Function Hardware at DoorwaysPlus.com
DoorwaysPlus.com stocks and sources asylum function mortise locksets from preferred institutional hardware lines including Sargent, Corbin Russwin, and Hager. Whether you need a straightforward mechanical Function 17 for a memory care renovation or a fully electrified fail-safe asylum lock integrated into a new behavioral health wing, our team can help you confirm the function code, door prep, voltage, and wire pathway before you order.
Have a hardware schedule with asylum function openings? Contact DoorwaysPlus.com -- we review schedules and quote preferred-brand alternatives at no charge.