Camden CX-91S-12-BK 1200 lbs Surface Mount Magnetic Lock
The Camden CX-91S-12-BK is a 1200 lbs surface mount electromagnetic lock designed for single-door access control installations in retrofit and new-build environments. Operating at 24VDC with field-selectable 12/24VDC input, this lock holds standard aluminum and steel door frames under sustained load without drift or solenoid creep. Surface mount configuration fits flush against the door frame header, eliminating the need for mortise modification — a critical advantage when retrofit speed or frame integrity matters. Built-in MOV surge protection shields the lock and upstream control circuits from voltage transients, a real concern in integrated panels running multiple solenoids off a single supply.
Key Features
- 1200 lbs holding force: Rated for continuous load on standard single doors. Surface mount design requires no frame modification, reducing installation time and cost.
- 24VDC field-selectable 12/24VDC: Accepts either voltage input — switch the DIP jumper on installation. Supports both hardwired panels and cloud-connected controllers with relay output.
- HID proximity-reader compatible: Works with any 12/24VDC card reader (proximity, smart card, keypad) feeding relay control signal to the lock coil.
- MOV surge protection integrated: Prevents voltage spikes from damaging the solenoid or downstream control circuits in multi-lock installations.
- UL 1034 and ULC S533-15 rated: Complies with burglary-resistant electric locking and access/egress safety standards. Suitable for high-traffic public-facing doors and secured perimeter entry.
- Optional door-status feedback: Integrate a separate TDS (Timer/Door Sensor/Relay) module to add adjustable release timer, magnetic position sensor feedback, and NC/NO door-status switch contact for integration into larger multi-door or building management systems.
- Low current draw: Base unit 240mA @ 24VDC; TDS option 285mA. Confirm your power supply has 500mA+ available to avoid voltage sag during simultaneous multi-lock release.
- Vandal-resistant stainless housing: 9 × 7.25 inch surface footprint. Flush mount design resists tampering and blends into modern door-frame aesthetics.
The CX-91S-12-BK integrates into any 12/24VDC hardwired access control system without special connectors — standard 18/2 or 16/2 twisted pair cable suffices. Field wiring runs directly from the reader relay output (or panel card-slot output) to the lock coil and common ground. Installation requires only a drill, template (included), and screwdriver. No special solenoid drivers or intermediate isolation relays are needed unless the door already has status-monitoring requirements, in which case the optional TDS module bridges that gap with a 0.5A @ 28V AC/DC rated switch contact.
Retrofit scenarios are where the CX-91S-12-BK excels. Many existing door frames cannot tolerate mortise drilling — commercial curtain-wall systems, reinforced frames, or heritage structures — and surface mount eliminates that constraint entirely. Installation time drops to under 30 minutes per door when mounting template is used; no frame fabrication required. The stainless housing resists salt spray and corrosion in high-traffic lobbies, parking-garage stairwells, and outdoor canopy entries. Current draw is conservative enough that a single 24VDC 500mA supply can service two to three CX-91S units on a relay sequencer, provided dwell time (door open) doesn't exceed 3–5 seconds per release cycle.
For larger deployments (8+ doors), modular approach is cost-effective: run a single 24VDC @ 2A power supply through a relay panel, then field-wire each door's reader output to a dedicated relay module before the lock coil. This architecture scales without adding separate 24VDC supplies at each door. The lock's built-in MOV protection keeps the relay contacts clean and extends their service life. ONVIF-compatible building management systems (Genetec, Avigilon, Salto) can trigger remote release via IP-to-relay gateway devices, making the CX-91S a cost-effective backdoor lock for organizations with cloud-based access platforms that lack native hardwired solenoid output.
Compliance posture: UL 1034 (Burglary-Resistant Electric Locking Mechanisms) and ULC S533-15 (Access and Egress) certifications make the CX-91S suitable for high-security and life-safety applications — healthcare facilities, government offices, financial institutions, and secure warehouses. The lock does not impose egress delays; pull-to-exit force is minimal (under 5 lbs) in case of fire-alarm activation or manual release. Manufacturer warranty covers the housing, armature, and solenoid coil for the life of the product, with field-replaceable coil cartridges available as spares. Nearest alternatives (Securitron MAGLOC, Assa Abloy Empowered Locking) cost 30–50% more and target larger multi-door campuses; the CX-91S wins on simplicity and retrofit speed for single-door or small 2–4 door installs where RFID audit trails aren't required. Consider the TDS module if you need door-position monitoring or adjustable hold-time, but for basic push-to-enter proximity access, the base unit is the right spec.
Jerry TildsenPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
We've installed the CX-91S-12-BK in retrofit scenarios where frame mortise drilling was off the table — commercial office lobbies, healthcare clinic entries, and bank branch drive-through security gates. The surface mount form factor is the real win: no frame modification, minimal downtime, and the lock sits flat against the header so it doesn't interfere with door hardware or closer arms. We've seen integrators spec this lock as the "fast retrofit" choice when a customer wants to add proximity access control to an existing manual door in under an hour. The DIP-selectable 12/24VDC voltage is underrated — it means your crew doesn't need to stock two SKUs, and field techs can swap in 12VDC if the building runs legacy fire-alarm 12V supplies without pulling a new circuit. Holding force is solid at 1200 lbs; we haven't had a drift complaint even on high-traffic doors swinging 50–100 times per day. The integrated MOV surge protection has prevented more than a few control-panel callbacks — a cheap insurance policy against voltage spikes from nearby HVAC solenoids or relay banks on the same breaker. Downsides: no built-in door-position feedback on the base unit, so if you need status reporting, you're adding the TDS module and its wiring. The current draw is light (240mA), but we always confirm the 24VDC power supply has at least 500mA headroom — we've seen brownouts on undersized supplies during simultaneous two-door releases. Not an issue if you're using a modern access-control panel with built-in sequencing, but important on DIY hardwired installs.
Technical Highlights:
- 1200 lbs holding force rated: Sufficient for standard aluminum and steel frames on both entry and exit sides. Not sufficient for high-traffic heavy doors (security vestibules, man traps) — those need 1600+ lbs magnets. This is the sweet spot for office and retail single doors.
- Surface mount + field-selectable 12/24VDC: Eliminates frame modification and simplifies inventory — one SKU covers both 24VDC hardwired panels and legacy 12VDC systems. Installation time under 30 minutes with template.
- MOV surge protection built-in: Protects the solenoid and upstream relay circuits. In multi-lock installations (3+ doors on one supply), this protection keeps the relay contacts clean and extends their life beyond typical 1–2 year replacement cycles.
- UL 1034 and ULC S533-15 rated: Meets burglary-resistant and life-safety egress standards. Critical for healthcare, government, and high-security verticals where non-compliant hardware creates liability and audit risk.
- Optional TDS module adds door-position feedback: If you need status reporting or adjustable hold-time, the separate TDS (Timer/Door Sensor/Relay) adds magnetic sensor feedback and a 0.5A @ 28V AC/DC NC/NO switch contact. Adds ~$200 to BOM but bridges integration gaps with building management systems.
- Field wiring simplicity: Standard 18/2 twisted pair from reader relay output to lock coil. No solenoid driver, no isolation relay required on most standard 12/24VDC access panels. Reduces system cost and support complexity.
Deployment Considerations:
- Retrofit reality: Confirm the door frame header has at least 9 inches of horizontal clearance. Some curtain-wall systems and narrow mullions don't provide it — template helps catch this before drilling.
- Current draw: Base unit 240mA, TDS option 285mA. On simultaneous multi-door releases, ensure your 24VDC supply has 500mA+ capacity to avoid voltage sag and failed releases. We've seen this trip up DIY integrators using undersized wall-mount supplies.
- Door-position feedback: Base unit has no status switch. If your access-control system or building management platform needs to know whether the door is open or closed, budget for the optional TDS module and its additional field wiring.
- Egress time: Lock releases instantly on loss of power (fail-safe mode) — no egress delay. Confirm with your local authority having jurisdiction (AHJ) that fail-safe is acceptable for your use case (usually yes for office/retail; may require fail-secure + backup power in healthcare/correctional facilities).
- Solenoid replacement: Field-replaceable coil cartridge — no need to remove the entire magnet assembly. Spare cartridges are inexpensive and stocked by most distributors, reducing mean-time-to-repair on high-traffic doors.
The CX-91S-12-BK is the right pick for integrators and security teams retrofitting single-door proximity access control where frame drilling is infeasible or downtime must be minimized. Surface mount + field-selectable voltage + built-in surge protection make it a low-fuss, fast-deploy choice. For larger campuses (8+ doors) or systems requiring distributed door-status monitoring, evaluate cloud-connected smart locks or modular fail-secure systems instead. For your single-door retrofit and small 2–4 door clusters, this lock delivers reliability and simplicity. Explore the full range of Camden access-control and locking hardware in the Camden catalog.
