What This Article Covers and Who It Helps
When a specifier or contractor selects a fail safe electrified mortise lockset with both levers locked and no cylinder override, they are making a deliberate life-safety and security choice that has real consequences in a power failure. This guide explains what that configuration actually does, where it belongs, where it does not belong, and what questions to resolve before the opening ships. It is written for architectural specifiers, commercial hardware installers, and facility managers who are evaluating or commissioning an electrified opening in a healthcare, institutional, or controlled-access environment.
What Does "Fail Safe, Both Levers Locked, No Cylinder Override" Actually Mean?
In electrified mortise hardware, fail safe means the lock defaults to the unlocked or free-egress condition when electrical power is removed. The solenoid or motor releases the locking mechanism so levers operate freely without power.
The both levers locked function means that under normal powered operation, neither the inside nor the outside lever can retract the latch without an access credential or remote release signal. The door is locked from both sides during normal operation.
No cylinder override means there is no mechanical key cylinder on the lockcase or trim that can manually release or retract the bolt independent of power. There is no fallback to a physical key for routine access or emergency egress from the secure side.
Put those three together and you get a very specific operational profile: the door stays locked on both sides as long as power is present and no credential is granted. The moment power drops, both levers free up automatically. There is no way to manually key it locked or unlocked from either side.
Why Would Anyone Specify This Configuration?
The absence of a cylinder override is not an oversight. It is an intentional design choice in specific environments where a physical key represents a security or operational risk that outweighs its convenience value.
- Behavioral health and psychiatric facilities: A key on the door is a target. Cylinder-free trim removes one more object that can be manipulated, forged, or coerced from staff.
- Controlled pharmaceutical storage: Access is managed entirely by the access control system. A mechanical override bypasses the audit trail.
- High-security server rooms and data centers: Every entry event must be logged. A key cylinder allows unlogged entry, which violates security policy.
- Certain institutional applications: Correctional adjacency spaces or controlled-movement corridors where credential-based access is the only acceptable mode.
In each of these settings, the access control system is the key. Removing the cylinder is a policy decision backed by the security program, not a hardware shortcut.
The Power Failure Question: What Really Happens
This is where many specifiers stop reading and start guessing. Here is the honest field answer.
When power drops on a fail safe lock with no cylinder override:
- Both levers become free-turning. Anyone on either side can retract the latch and open the door without a credential.
- There is no mechanical way to re-lock the door until power is restored.
- If the opening is on a life-safety egress path, this behavior is generally code-compliant because egress is never impeded.
- If the opening is a perimeter security barrier, a power outage creates an unlocked gap in the security envelope until power or backup power restores control.
This is why battery backup or an uninterruptible power supply on the access control power distribution is nearly always part of the design package when this function is specified. Fail safe does not mean fail open and unprotected forever; it means your power architecture has to be designed to match the risk profile of the opening.
Generator Power Is Not Enough on Its Own
Generator transfer takes seconds to minutes. During that gap, a fail safe lock without battery bridge power is unlocked. For a behavioral health corridor or a pharmaceutical room, that gap matters. Specify a power supply with battery backup sized to bridge the generator transfer and any extended outage window your security program requires.
Code Considerations You Cannot Skip
The International Building Code and NFPA 101 both address electrified locking on egress paths. Key points that apply to this configuration:
- Free egress requirement: On most egress doors, occupants must be able to exit without special knowledge or a key. A fail safe lock satisfies this when power drops, but your authority having jurisdiction (AHJ) will want to confirm that the powered state also allows egress or that a proper controlled-egress exception applies.
- Controlled egress exceptions: Healthcare occupancies under NFPA 101 permit certain doors to restrict egress during normal operation, subject to specific conditions including staff monitoring, timed release, and compliant alarm integration. Both-levers-locked configurations may fall under these provisions depending on the occupancy and the AHJ interpretation.
- Fire alarm integration: Where required, electrified locking must release upon fire alarm signal. Confirm that your power supply and control circuit are wired to release on alarm. A fail safe lock will release on power loss, which includes a properly wired fire alarm shutdown, but the control logic must be engineered and documented.
- NFPA 80 fire door requirements: If the opening carries a fire rating, confirm that the electrified mortise body and trim are listed for the door rating. Not every electrified mortise chassis is rated for fire door use.
Always involve the AHJ early when specifying both-levers-locked electrified functions in any occupancy other than a straightforward office or retail application.
Wiring Reality: EcoFlex and Voltage Flexibility
Modern electrified mortise locks in this class often accept 12VDC or 24VDC input, which matters because access control panels vary. Verify that your power supply voltage matches the lock, that your wire gauge is appropriate for the run length, and that voltage drop at the lock stays within the manufacturer's tolerance — typically plus or minus ten percent of rated voltage. A lock that receives insufficient voltage may not actuate reliably, creating intermittent lock or unlock failures that are difficult to diagnose in the field.
For openings in hollow metal doors without pre-wired harnesses, power transfer from frame to door requires either a door cord (electric power transfer), electric hinges, or a mortised power transfer device. Selecting a transfer method is part of the opening spec, not an afterthought on the day of installation.
Where This Function Does Not Belong
Specifying no-cylinder-override fail safe on the wrong opening creates serious operational problems.
- Any opening where staff must re-secure the door manually after a power event: Without a cylinder, there is no manual lock. The door stays unsecured until power returns.
- Stairwell re-entry doors: These require specific egress compliance and often have different re-entry locking requirements that a no-override lock may not satisfy without supplemental hardware.
- Exterior perimeter doors at facilities without backup power: A utility outage leaves the building perimeter unlocked with no manual remedy.
- Any opening where the owner's maintenance team needs routine mechanical access independent of the access control system: The absence of a key means a credential or a powered system is always required for access.
Specifying and Sourcing This Hardware
Electrified mortise locks in the fail safe, both-levers-locked, no-cylinder-override configuration are available from preferred commercial lines including Accentra (formerly Yale Security), Corbin Russwin, Sargent, and Hager. The right choice depends on the door prep already in place, the trim style required, the finish specified, and whether the door manufacturer has pre-wired the door for a plug-in connector system.
DoorwaysPlus.com carries electrified mortise hardware across these preferred lines and can help confirm compatibility with your door prep, your access control power supply, and your project's finish schedule. If you are replacing an existing electrified mortise on a door already prepped to a standard pocket dimension, a direct-replacement body from a stable product line saves significant labor compared to re-prepping the door for a different chassis geometry.
The Decision Checklist Before the Opening Ships
- Has the AHJ reviewed and accepted the both-levers-locked, fail-safe configuration for this occupancy?
- Is fire alarm integration specified and engineered in the electrical drawings?
- Is backup power specified for the access control circuit serving this lock?
- Is the power transfer method (door cord, electric hinge, pre-wired harness) included in the opening spec?
- Is the wire gauge adequate for the run length at the operating voltage?
- Has the door manufacturer confirmed the mortise pocket dimensions and fire label compatibility?
- Does the security program explicitly accept that no mechanical key override exists at this opening?
If any of these questions are open when the schedule ships, the opening will create a problem at commissioning or during the first AHJ inspection. Resolve them at the spec stage, not on the job site.