ML20906 Corbin Russwin Electrified Mortise Lock: Specs, Functions and Ordering Guide

The ML20906 is Corbin Russwin's electrically controlled mortise lock built on the ML2000 Series platform - the same mechanical body that specifies on commercial openings across healthcare, education, and government facilities. Certified to ANSI/BHMA A156.13 Series 1000 Grade 1, UL listed under UL10C Positive Pressure for 3-hour fire assemblies, and compliant with ANSI A117.1 accessibility standards, it comes in two electrical functions: fail safe and fail secure. It operates on 12 or 24 volts DC, draws 15mA continuously, and accepts every ML2000 Series trim design. This guide covers every specification decision that matters before the order ships.

What Separates the ML20906 From Standard ML2000 Hardware

The mechanical ML2000 Series is one of the most installed commercial mortise locks in North America. The ML20906 takes that proven body and adds direct electrical control of the outside grip - the latchbolt is released or locked remotely by the access control system, at the lock itself, not downstream at a separate electric strike.

That distinction matters on high-security openings. An electric strike at the door frame can be bypassed with a credit card shimmed against a spring latch. The ML20906 controls the latch at the source: the outside lever is mechanically disengaged from the lock body until the system authorizes entry. The inside lever remains in passage mode at all times - egress is never blocked by the electrical state of the lock, which satisfies the code requirement for any door on an occupied building's egress path.

The lock installs in a standard mortise prep with a slight modification by the door manufacturer, meaning existing hollow metal or wood doors built for the ML2000 body require minimal rework. The patented quick-reversible latchbolt allows door handing to be changed on site without disassembling the body - a practical time-saver on large projects where handedness is not confirmed until the door arrives.

Fail Safe or Fail Secure: The Decision That Cannot Be Fixed on Site

This is the first specification decision and the most consequential. The wrong function code means the lock must be replaced - it cannot be converted in the field.

ML20906 SAF (Fail Safe) operates as follows: the lock is de-energized in its normal rest state and the outside lever operates freely. When the access control system applies power, the outside grip locks and the door is controlled. When power fails - whether from a building outage, fire alarm panel activation, or system fault - the lock de-energizes and the door opens freely.

The SAF function belongs on:

• Corridor doors and stairwell entries on required egress paths

• Assembly area and classroom entries where free exit during emergencies is mandatory

• Any opening where "default unlocked" is the life-safety requirement

ML20906 SEC (Fail Secure) is the opposite. The lock is locked when power is off and unlocked when the system energizes it. Cut the power and the door defaults to secured.

The SEC function belongs on:

• Data centers and server rooms

• Pharmacy storage and controlled substance areas in healthcare

• Restricted access corridors and executive suite entries

• Any opening where "default locked" is the safe state regardless of power status

In both variants the auxiliary latch deadlocks the latchbolt with a 3/8-inch throw. The main latchbolt throws 9/16-inch. Key override via the single cylinder operates the latch when the lock is in its non-energized state, providing mechanical backup in both SAF and SEC configurations.

Electrical Specifications and Power Supply Sizing

The ML20906 accepts 12VDC or 24VDC - the same lock body covers both voltages without modification. Continuous current draw is 15mA regardless of voltage. Peak current draw is 0.5A. Corbin Russwin specifies a hard maximum of two ML20906 locks per 1-amp power supply. That figure drives the power supply count for any multi-door project. A project with 10 ML20906 locks requires a power supply capable of supporting at least five pairs - and that assumes even distribution.

Full electrical specifications:

• Input voltage: 12VDC or 24VDC (must stay within ±10% of nominal)

• Continuous draw: 15mA

• Peak draw: 0.5A

• Maximum locks per 1A power supply: 2

• Monitor switch rating: 2A @ 24VDC

• Operating temperature: -13°F to 151°F (-25°C to 66°C)

• Operating humidity: 5% to 95% non-condensing

These figures need to go to the access control integrator before the system design is finalized. Confirming power supply sizing before the order ships prevents a redesign after installation begins.

Monitor Options: M91 and M92 Explained

Two factory monitor options are available on the ML20906, and they serve different functions in the access control system.

M91 (Latchbolt Monitor) monitors the position of the latchbolt - specifically whether it has fully retracted and latched. This is the signal used when the access control panel needs to confirm the door has closed and latched completely, not just that the lever was operated. It is specified on high-security openings where an unlatched door must trigger an alert at the panel.

M92 (Request to Exit Monitor) is a SPDT switch that monitors the activation of the trim itself. Both the inside and outside levers activate the switch simultaneously. The RTE signal fires when either lever is depressed, telling the access control panel that someone is using the door. This is the standard integration point for suppressing re-lock timers, logging exit events, and triggering door activity monitoring.

Both are factory-installed options. Neither can be retrofitted after the lock body ships. Specify the correct monitor option on the order, not after the hardware arrives.

Trim, Finish, Sustainability and Related Models

The ML20906 accepts the complete ML2000 Series trim library - including the Vineyard Collection and Muséo Collection lever designs - making it compatible with architectural finish specifications across every major project type. Available finishes include 605 polished brass, 606 satin brass, 612 satin bronze, 613 dark oxidized bronze, 619 satin nickel, 626 satin chrome, and stainless options. The NSA 626 configuration - NS lever, A rose, satin chrome finish - is the most commonly specified variant in institutional applications.

The ML20906 carries GreenCircle Certified Life Cycle Assessment Optimized designation. For institutional procurement - federal government, healthcare systems, and university facilities - where LEED credits and sustainable procurement policies apply to hardware specifications, this certification can directly affect which product the procurement officer approves.

For applications requiring no cylinder override, the ML20907 body uses the same electrical specifications and trim library with key bypass of the electrical function removed. For double cylinder configurations, the ML20932 and ML20987 cover SAF and SEC variants respectively. All models in the ML20900 series share the same 12/24VDC electrical spec, the same power supply sizing limits, and the same monitor options.

Why American Locksets Is the Right Source for the ML20906

Electrified hardware projects punish specification errors more than any other product category in commercial door hardware. A mechanical mortise lock ordered in the wrong function can be swapped out in a morning. An ML20906 SAF installed on a data center entry where the schedule called for SEC requires a full lock body replacement, a return authorization, a coordination call between the integrator and the contractor, and a line item in the project budget that nobody planned for.

The conversation we have before the order ships is the one that prevents that. Twenty-four years as an authorized Corbin Russwin dealer means we have seen the return authorization scenario, and it starts the same way every time: a supplier who does not catch the function code discrepancy because nobody confirmed SAF vs SEC against the door's actual life-safety requirement.

When a contractor or integrator calls 877-471-4870 with an ML20906 requirement, we confirm the function, cylinder type, trim series, finish, and monitor option before anything ships. Both the ML20906 SAF and ML20906 SEC are in authorized stock. For projects where power supplies, RTE devices, and electrified hardware ship together, our electronic hardware section carries those components on the same order. The full commercial mortise lock range is in our commercial locks section, and the complete electrified mortise lock lineup is in the electrified mortise locks section. Same-day shipping from multiple US warehouses.

Conclusion

The Corbin Russwin ML20906 is a Grade 1 electrified mortise lock with direct electrical control of the outside grip, built on the ML2000 platform, available in fail safe and fail secure functions that define the door's default behavior during any power loss. It draws 15mA continuously on either 12 or 24 volts DC, supports two locks per 1-amp supply, carries ANSI A156.13 Grade 1 and ANSI A117.1 accessibility certifications, and is UL10C listed for 3-hour fire assemblies. M91 and M92 monitor options are factory-installed - specify at order time. The lock also carries GreenCircle Certified Life Cycle Assessment Optimized designation for sustainable procurement compliance. American Locksets stocks both variants from authorized Corbin Russwin distribution with same-day shipping from multiple US warehouses. Call 877-471-4870 or visit our electrified mortise locks section to confirm the specification.

Frequently Asked Questions

What is the Corbin Russwin ML20906?

 A Grade 1 electrified mortise lock on the ML2000 platform, ANSI A156.13 certified, UL10C listed for 3-hour fire assemblies, available in fail safe and fail secure.

What is the difference between ML20906 SAF and SEC? 

SAF is unlocked when power is off - for egress paths. SEC is locked when power is off - for secured rooms. Inside lever always free in both.

What voltage and current does the ML20906 require?

 12 or 24VDC at 15mA continuous draw. Peak 0.5A. Maximum two locks per 1-amp power supply.

What is the difference between M91 and M92 on the ML20906? 

M91 monitors latchbolt position. M92 is a SPDT request-to-exit switch that fires when either lever is activated. Both are factory-only options.

Is the ML20906 GreenCircle Certified?

 Yes. It carries GreenCircle Life Cycle Assessment Optimized certification, relevant for LEED and sustainable institutional procurement requirements.

What is the ML20907 and how does it differ?

 ML20907 removes the single cylinder override. Same electrical specs and trim compatibility, no key bypass of the electrical function.

Where can I buy the Corbin Russwin ML20906?

 American Locksets stocks both ML20906 SAF and ML20906 SEC from authorized stock. Call 877-471-4870.

Published by the American Locksets Hardware Team. Authorized Corbin Russwin Dealer, Est. 2001, Monroe, NY.