What This Article Covers and Who It Helps
When a facility manager, electrical sub, or hardware specifier orders an electrified mortise lockset, one question reshapes every other decision on that opening: what happens when the power goes out? Choosing between fail safe and fail secure is not simply a product preference. It is a code, life-safety, and security workflow decision that must be resolved before the hardware ships. This guide walks through the real factors that drive that choice, the opening types where each mode is appropriate, and the coordination required to get it right.
What Fail Safe and Fail Secure Mean
These two terms describe the default state of an electrified lock when electrical power is interrupted.
- Fail safe: The lock releases and the door can be opened without credential or key when power is lost. Power is required to hold the lock in the locked state.
- Fail secure: The lock remains locked when power is lost. Power is required to unlock the device, typically by energizing a solenoid that retracts a blocking element.
An electrified mortise lockset such as the Accentra 8800 series in fail safe configuration uses a continuous low current draw to maintain the locked state during normal operation. Loss of power -- whether from a tripped breaker, a fire alarm relay, or a power supply failure -- immediately frees the outside lever, allowing egress or entry without a credential.
Where Each Mode Belongs: Opening-by-Opening Logic
The right mode is determined by who needs to get through the door during an emergency, not just who uses it during normal business hours.
Fail Safe Applications
- Egress-critical doors on the path of travel: Stairwell re-entry doors, corridor doors to exit stairs, and assembly occupancy entries where occupants must be able to evacuate freely if building systems fail.
- Fire alarm-integrated openings: Many jurisdictions and codes require that electrified locks release upon activation of the fire alarm system. A fail safe lock wired through a fire alarm relay accomplishes this automatically.
- Healthcare patient room doors: In hospital or behavioral health settings, the ability for staff to access a room during a power or system failure is often a clinical and life-safety requirement.
- School main entry vestibules: Where the controlled entry must fail open to allow emergency responder access or occupant exit without credential during an evacuation.
Fail Secure Applications
- Server rooms, IT closets, and data centers: A power interruption -- including one caused deliberately -- should not grant access to sensitive infrastructure.
- Pharmacy and medication storage in healthcare: DEA and facility policy routinely require that controlled substance storage remain locked regardless of building power status.
- Utility and mechanical rooms in commercial buildings: Electrical, HVAC, and telecom equipment rooms are legitimate fail secure candidates when the risk of unauthorized access during an outage outweighs egress concerns.
- High-value retail back-of-house: Stockrooms and cash handling areas where the threat of a deliberate power interruption as a forced-entry tactic is a documented risk.
The Code Constraint That Overrides Everything
The authority having jurisdiction (AHJ) and the applicable edition of the International Building Code or NFPA 101 may restrict fail secure installations on doors that serve as required egress. NFPA 101 and IBC both include provisions for electrically controlled egress door assemblies, and the manufacturer's installation instructions for the Accentra 8800 series electrified mortise line state plainly: the system shall not be installed in fail secure mode unless permitted by the local authority having jurisdiction and shall not interfere with the operation of listed panic hardware.
In practical terms, this means:
- Any door on a required exit access corridor is almost certainly a fail safe installation unless the AHJ specifically approves otherwise.
- Fail secure on a door that also carries panic hardware requires careful review -- panic hardware must always allow free egress, and the electrified function must not defeat that.
- Fire-rated assemblies that are part of a fire alarm interface will typically be wired to release on alarm, making fail safe the logical choice even when fail secure might otherwise apply.
Always confirm the mode with the AHJ and the fire alarm contractor before the hardware schedule is finalized.
Power and Wiring Decisions That Follow From the Mode Choice
Once fail safe or fail secure is selected, a chain of downstream decisions follows immediately.
Current Draw and Power Supply Sizing
Fail safe mortise locksets draw current continuously to maintain the locked state. The Accentra 8800 series EcoFlex platform operates at 12VDC or 24VDC and is designed for low continuous current draw, but the power supply must be sized to support the total load of all devices on the circuit. Wire gauge selection is also run-length dependent -- longer wire runs require heavier gauge to avoid voltage drop outside the allowable operating range.
Power Transfer to the Door
An electrified mortise lock mounted in a swinging door requires a path for power to travel from the fixed frame to the moving door leaf. Options include electrified hinges (including ElectroLynx-compatible models), door cords, or pivot-mounted power transfer devices. Doors manufactured by ASSA ABLOY group companies may come pre-wired with ElectroLynx connectors, simplifying this connection significantly. Doors without factory harnesses require field wiring through a retrofit approach or hard-wired connections made with appropriate crimp splices or wire nuts per local code.
Fire Alarm Interface
If the opening requires fail safe behavior on fire alarm activation, the power supply or control panel must include a relay that interrupts power to the lock when the fire alarm trips. This is a coordination item between the hardware contractor, the electrical sub, and the fire alarm contractor -- and it must be reflected in the door hardware schedule and the electrical drawings before rough-in.
Specifying the Right Function Code
Electrified mortise locksets are available in a range of function codes that combine the mechanical behavior of the lock (how the inside and outside levers operate mechanically) with the electrified behavior (which element is energized and what happens on power loss). A fail safe outside-lever-locked function -- like the Accentra 8800FL configuration -- means the outside lever is locked during normal powered operation and releases freely when power is removed. The inside lever typically remains free for egress at all times regardless of power state.
Getting the function code right before the door is prepped matters because the mortise pocket is cut to match the lock body, and the trim holes are drilled to match the cylinder and lever configuration. A function change after installation can require reprepping the door edge -- an expensive field correction that specification review before order placement prevents.
Coordination Checklist Before the Order Ships
- Confirm fail safe or fail secure with the AHJ and the fire alarm contractor
- Verify the function code matches the mechanical and electrified behavior required at each opening
- Identify the power transfer method -- ElectroLynx hinge, door cord, or hard wire
- Size the power supply for total device load and wire runs
- Confirm voltage -- 12VDC or 24VDC -- is consistent across all devices on the circuit
- Check fire alarm relay interface requirements with the electrical and fire alarm subs
- Verify that fail secure is permitted by the AHJ on any opening where it is proposed
Finding the Right Hardware for Your Project
DoorwaysPlus carries electrified mortise locksets from Accentra (formerly Yale), Corbin Russwin, Sargent, and other preferred lines in both fail safe and fail secure configurations, across a range of function codes and voltage options. If you are building a hardware schedule and need help matching the right electrified function to each opening type, our team can assist. Browse electrified mortise hardware at DoorwaysPlus.com or contact us with your schedule for a quote.