SDC LR100ARK-EM Adams Rite Motorized Electric Latch Retraction Kit
The SDC LR100ARK-EM is a retrofit motorized electric latch retraction actuator engineered for panic and fire-rated mechanical exit devices in high-traffic commercial deployments. Unlike solenoid-based operators, the motor-driven mechanism retracts the exit device latch and holds the pushpad in a depressed position when energized — enabling hands-free push-and-pull door operation via access control integration, remote triggering, or building automation. The operational benefit is measurable: 700mA inrush current is substantially lower than solenoid alternatives, reducing strain on 12VDC or 24VDC power supplies and control wiring. The motor design eliminates the need for external door sequencers on manual-swing doors, simplifying the wiring topology and reducing panel-side complexity.
Key Features
- Motor-Driven Latch Retraction: 700mA inrush current (vs. 3–5A for solenoid operators). Significantly reduces power-supply and wiring overhead on retrofit installations.
- Field-Retrofit Design: Mounts entirely within the exit device rail behind the access cover without removal of the device itself. Installation can occur on-site without device replacement.
- Broad Device Compatibility: Works with panic and fire-rated exit devices from Adams Rite, Arrow, Cal Royal, Corbin Russwin, Design Hardware, Detex, Dorma, Dor-O-Matic, Falcon, First Choice, Hager, IDC, Jackson, Marks, Marshall Best, Pamex, PDQ, PHI, Sargent, SDC, Stanley K2, Tell, Townsteel, Von Duprin, and Yale.
- Multiple Opening Widths: Available configurations support 36", 36"–48", 42", and 48" door openings. Verify your specific device model against manufacturer compatibility matrix before ordering.
- Voltage Flexibility: Activates via 12VDC or 24VDC access control circuits, remote control devices, or building automation interfaces. Coordinate voltage and control signal type with your existing panel.
- Life-Safety Compliant: Egress remains uninhibited regardless of energization state. Door always unlocks from the occupancy side, maintaining code-mandated emergency egress pathways.
- No Door Sequencer Required: Motor design eliminates the need for external sequencing devices on manual-swing doors, reducing BOM complexity and wiring runs.
The LR100ARK-EM integrates into mid-scale access control environments where retrofit solutions are preferred over full device replacement. It is particularly suited for facilities managing multiple panic/fire-rated exit points that require synchronized access control without capital-intensive hardware swaps. Common applications include high-traffic tenant spaces, healthcare facilities, educational institutions, and commercial office buildings where emergency egress code compliance and operational simplicity are non-negotiable.
Installation does not require removal of the exit device from the door frame. Position the unit entirely within the device rail, connect the 12VDC or 24VDC signal lines to your access control panel or relay circuit, and verify egress operation before placing the door back into service. Wire gauge and run lengths should follow standard control-circuit best practices (typically 18–22 AWG for signal runs under 500 feet). The motor mechanism is designed for sustained operation in high-traffic scenarios where solenoid chatter and duty-cycle limitations would otherwise demand frequent maintenance or replacement.
The LR100ARK-EM operates independently of networked access control platforms but can be managed through a dedicated 4-door controller (such as the SDC LR100 series) that supports HID credentials and communicates via OSDP and TCP/IP protocols. This allows integrators to centralize credential management across multiple doors while maintaining the electrical simplicity and retrofit advantages of motor-driven latch retraction. For facilities standardizing on panic/fire-rated exit devices, this architecture reduces total cost of ownership by deferring device replacement cycles and eliminating the power-supply overhead associated with solenoid operators.
Jerry TildsenPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
In our experience with mid-market panic device retrofits, the LR100ARK-EM solves a real problem: how to retrofit access control onto existing fire-rated exit devices without ripping out hardware that is often only 5–8 years into its lifecycle. We've deployed these on tenant-fit-out projects where the building standard is Adams Rite or Von Duprin, and the tenant's access control requirement arrives late. Instead of a $400–600 per-door device replacement plus hinge and frame modifications, the motor retrofit runs $150–250 in material, installs in under 30 minutes per door, and requires zero structural modification. The 700mA inrush current is the quiet technical win — on a 16-door panel powered by a single 24VDC 5A supply, solenoid operators would force a panel upgrade; the motors don't. We've also found that the lack of door sequencer requirement simplifies wiring on retrofit jobs where conduit space is constrained. The trade-off is honesty: this is not intelligent access control. It's a dumb actuator, which means your credential management, audit logging, and policy enforcement all live in the upstream controller or cloud platform. That's not a limitation — it's appropriate architecture for retrofit scenarios.
Technical Highlights:
- Motor vs. Solenoid Inrush: 700mA sustained current draw versus 3–5A inrush on solenoid operators. On multi-door retrofits, this translates to smaller 24VDC power supplies (5A supply covers 6–8 motor doors instead of 2–3 solenoid doors) and lighter-gauge control wiring (18 AWG runs 500+ feet without voltage drop issues).
- Field-Retrofit Mounting: No device removal, no frame modification, no hinge work. The actuator mounts inside the existing rail — you verify compatibility, install the motor, wire to your panel, and the door is back in service same day. On tenant fit-outs with existing building hardware, this is a 10x faster deployment than device replacement.
- Brand Ecosystem Compatibility: Validates with 15+ OEM exit device brands. Before spec'ing, always pull your site's device inventory and cross-reference against the SDC compatibility matrix — a mismatch means field-engineering workaround or device replacement (the thing we're trying to avoid).
- Life-Safety Passive Design: Motor is de-energized in normal state; door is mechanically closed and latched. Loss of power = door stays locked from the outside, egress remains free from the inside. This is a non-negotiable requirement for panic devices in life-safety codes, and the LR100ARK-EM handles it by design, not by exception.
- Voltage Flexibility (12/24VDC): Confirms with your panel's relay or supervised output before installation. Most integrators use 24VDC for longer wiring runs; 12VDC is sometimes seen on legacy panels or where 24VDC is not readily available. Coordinate early — a wiring swap post-installation wastes labor.
Deployment Considerations:
- Always verify your specific exit device brand and model against the SDC compatibility matrix before ordering. A mismatch discovered on-site means a return trip and either a workaround or device replacement. The matrix is detailed; use it.
- This is a retrofit actuator, not a smart controller. Your credential management, audit trails, and emergency unlock policies live in the upstream access control platform or 4-door controller. If you need local card readers or standalone operation, the LR100ARK-EM alone is not sufficient — you need the LR100 series controller and HID reader pair.
- Door opening width (36″, 42″, 48″) is a physical fit constraint. Measure your door opening and exit device rail length before specifying. Undersized motors will not retract fully; oversized kits may not fit within the rail housing.
- On high-traffic doors (retail, healthcare, education), verify that the motor mechanism is rated for the daily duty cycle you expect. SDC publishes cycle ratings in the datasheet — compare against your site's egress frequency. If you're running a 24/7 secure facility with 500+ egress events per day, confirm the motor endurance rating with the distributor.
- Wiring: keep signal runs shielded and separate from power feeds if the panel is running analog circuits. 18–22 AWG twisted pair is standard; unshielded runs over 500 feet may pick up noise on supervised door-status circuits. If the LR100 controller is monitoring the motor state (mechanical feedback), confirm signal integrity over your run length.
The SDC LR100ARK-EM is the right choice for integrators retrofitting access control onto existing panic and fire-rated exit infrastructure in mid-market commercial buildings, tenant spaces, and healthcare facilities where capital expenditure on device replacement is not available or justified. If your site already has compatible Adams Rite or Von Duprin hardware, this motor retrofit is typically 60–70% cheaper and 3–5x faster to deploy than full device replacement, with zero life-safety compromise. For more options in motorized exit hardware, see the full SDC catalog.
