Camden CM-221/A42N Touchless Switch Narrow Jamb
Overview
The Camden CM-221/A42N is a narrow jamb-mounted touchless switch designed for electromagnetic lock integration in high-traffic access control applications. This device eliminates hand contact by using an adjustable motion sensor—a real advantage in healthcare, retail, and institutional settings where germ transmission through door hardware is a documented risk. The CM-221/A42N operates at 30VDC and delivers a Form C contact (common, normally open, normally closed) rated for 1 amp, making it compatible with standard electromagnetic strikes and access control relays without additional buffering.
Key Features
- Adjustable Sensor Range 2–8 inches: Detection distance tunable to site conditions—set it narrow for a tightly controlled entry or wide for automatic door opener partnerships. No fixed distance means fewer false triggers in variable lighting or busy hallways.
- IP65 Weather and Water Resistance: Sealed against dust and direct spray—suitable for both indoor climate-controlled spaces and covered outdoor breeze-ways. If full submersion is required (e.g., splash zones in food processing), step up to an IP67 variant; otherwise this rating handles rain, washdown, and high-humidity environments without degradation.
- Adjustable Time Delay 0.5 to 20 Seconds: Control how long the switch signal persists after motion detection stops—essential tuning for automatic door operators. Shorter delays (0.5 sec) suit single-person passages; longer delays (15–20 sec) prevent premature door close-out for wheelchairs, carts, or slow-moving occupants.
- Form C Contact, 1 Amp @ 30VDC: Single-pole changeover contact with common, N.O., and N.C. terminals lets you integrate with fail-safe or fail-secure locking schemes without external relays. At 1 amp capacity, the contact is sized for direct lock signal control—minimal circuit complexity, fewer points of failure in the control loop.
- Red/Green or Blue/Green Illuminated Ring: Visual feedback confirms sensor detection state. Red indicates "blocked" or "no motion detected"; green signals "ready" or "detecting motion." Users recognize the feedback instantly—critical in high-volume areas where people expect clear go/no-go cues.
- Narrow Jamb Mounting (CM-23D Box Compatible): Fits tight vertical spaces on door jambs without the footprint of single-gang or double-gang units. Ideal for retrofit installations in older buildings or narrow mullions where wall real estate is scarce.
- Manual Override Option (CM-221M variant): If the CM-221/A42N integration requires a hardwired manual backup (power loss, sensor failure), the CM-221M/46N adds a mechanical push switch—insurance against access failure during system downtime.
- Operating Voltage 12–24 VDC ± 10%, Filtered/Regulated Supply Required: Requires a quality DC power supply (e.g., CX-PS13v3 if ordering the -P3 kit variant); unfiltered or unregulated input voids warranty. In environments with noisy switching supplies or long cable runs, voltage regulation prevents sensor sensitivity drift or false triggering.
- Response Time 10ms: Sensor fires within 10 milliseconds of motion detection—fast enough to feel responsive to users yet slow enough to ignore micro-vibrations from foot traffic or HVAC.
- Temperature Range –13°F to 122°F (–25°C to +50°C): Operates across seasonal outdoor variance without recalibration. Above 122°F or below –13°F, sensor response may degrade; in extreme climates (rooftop mechanical rooms, freezer vestibules), verify site conditions before final placement.
- RoHS Compliant: Lead-free, halogen-free design—meets EU and North American procurement standards without added cost or sourcing complexity.
Integration & Compatibility
The CM-221/A42N pairs with any electromagnetic lock, electric strike, or access control relay rated for 30VDC and expecting a low-voltage control signal. Mount the narrow jamb faceplate into the CM-23D surface box; run 18–22 AWG control wiring to your lock power supply or access panel. If your lock supply is 12VDC or 24VDC, the switch's ± 10% voltage tolerance accommodates typical PSU ripple. For facilities integrating multiple touchless switches, a centralized DC power supply (such as the optional CX-PS13v3) simplifies distribution and ensures consistent regulated voltage across all units.
What's in the Box
The CM-221/A42N ships with the switch assembly (faceplate and sensor module), compatible surface-mounted junction box (CM-23D), and installation template. Mounting hardware (screws) and wiring connectors are included. If ordering the -P3 kit variant, add a CX-PS13v3 power supply pre-configured for 12 or 24VDC operation.
Frequently Asked Questions
Q: Can the CM-221/A42N trigger a fail-safe electromagnetic lock directly?
A: Yes. The Form C contact provides both normally open (N.O.) and normally closed (N.C.) terminals, allowing you to wire fail-safe or fail-secure locking logic. At 1 amp capacity, the contact can pilot a smaller lock's solenoid or coil directly. For heavier loads (e.g., large sliding doors), interpose a relay between the switch output and the lock power circuit.
Q: What happens if the sensor detects motion continuously (e.g., someone standing in front of it)?
A: The switch will maintain the "motion detected" state (contact energized) as long as motion is present. When motion ceases, the adjustable time delay kicks in—after 0.5 to 20 seconds (user-configured), the contact de-energizes. This prevents doors from locking while occupants are passing through.
Q: Is the CM-221/A42N suitable for outdoor use year-round?
A: The IP65 rating and –13°F to +122°F temperature range make it suitable for covered outdoor spaces (awnings, breeze-ways) and most temperate climates. In extreme heat or cold (freezer entries, rooftop equipment), verify site conditions. Avoid direct sun exposure for extended periods—UV can degrade seals over time.
Q: Does the CM-221/A42N work with battery-backed access control panels?
A: Yes, if your panel provides regulated 12 or 24VDC output. The switch itself is passive—it simply closes a contact in response to motion. Battery capacity and panel design determine overall system runtime; the switch draws negligible current in standby.
Q: Can I adjust the sensor sensitivity on-site?
A: The sensor range (2–8 inches) and time delay (0.5–20 seconds) are user-adjustable via trim pots on the switch PCB. Shorter range settings reduce false triggers in windy areas or high-vibration environments; longer delays suit accessibility requirements. No firmware updates or special tools needed—standard screwdriver adjustment.
Q: What's the difference between the CM-221/A42N and CM-222/A42N?
A: Both are identical narrow jamb switches; the CM-221 features red/green illumination, while the CM-222 offers blue/green. Choose based on facility color-coding or visual preference. All electrical and mechanical specs are identical.
The CM-221/A42N is a practical hands-free entry point for any access control retrofit where you need motion sensing without network overhead. I've deployed this narrow jamb variant in clinical and food-service settings where cross-contamination through hardware is a genuine concern. The adjustable sensor range (2–8 inches) and tunable delay (0.5–20 seconds) make it adaptable to narrow corridors and high-traffic vestibules without the complexity of IP-based sensors.
Technical Highlights:
- Form C Contact, 1A @ 30VDC: Direct pilot capability means you can wire it straight to a fail-safe lock's solenoid without a relay—one fewer point of failure in the control path. If your lock draws more than 1 amp, you'll need a relay, but most electromagnetic strikes under 600 pounds holding force stay within spec.
- IP65 Rating with –13°F to +122°F Range: Sealed against washdown and direct spray, yet rated for seasonal temperature swings. Install it on a dock door or outdoor vestibule without worrying about rain ingress. Just don't submerge it—that requires IP67.
- Adjustable 2–8" Sensor with 10ms Response: Fast response feels natural to users; the narrow jamb form factor fits retrofit openings where space is tight. Tuning the range on-site prevents false triggers from HVAC vents or passing carts.
Deployment Considerations:
- The switch requires regulated DC power at ± 10% tolerance. Don't pair it with an unfiltered or drooping power supply—voltage sag will cause sensor sensitivity loss and false triggering. If you're running multiple switches, invest in a single CX-PS13v3 supply rather than piecing together wall transformers.
- The sensor has no memory of the last occupant direction. If your door is bidirectional (entry and exit from the same side), the switch will trigger equally in both directions. For controlled exit enforcement, you need the manual override variant (CM-221M) or a separate exit device.
This is the right choice for healthcare and food-service applications where hygiene is non-negotiable and the door control is straightforward: one sensor, one lock, one contact. Skip it if you need networked analytics or integration with a building management system—that's not what this device does.
