Camden Spring Return, DPST 1-60 SEC Pneumatic Time Delay, (Requires...

In our experience, the CM-7085 is a niche product that solves a specific problem: environments where electrical supply stability cannot be guaranteed or where simplicity and mechanical reliability outweigh software configurability. We've seen it deployed in hospital emergency departments, government buildings with aging electrical infrastructure, and high-security facilities where access control systems are intentionally isolated from networked infrastructure. The pneumatic mechanism is the key differentiator — it genuinely doesn't care whether your 24VDC supply is stable or fluctuating within spec. That immunity to brown-out and transient conditions makes it the preferred choice in facilities with unreliable backup power or high electrical load variability. Compared to solid-state timer modules (which offer more programmability but are susceptible to EMI and voltage ripple), the CM-7085 trades flexibility for robustness. It's a deliberate trade-off: you get mechanical simplicity, zero software overhead, and battlefield-proven reliability, but you lose the ability to change timing parameters from a central access control panel — adjustment requires physical access to the device and a screwdriver.

Technical Highlights:

• Pneumatic vs. Electronic Timing: The pneumatic mechanism operates on air regulation independent of electrical supply. This eliminates the false triggering and timing drift we've observed in RC-circuit timers during power supply sag events or when high-current strikes draw voltage down. In hospital environments with emergency generator handoff, this independence is worth the mechanical complexity.
• DPST Configuration with 6 Amp Contacts: Two independent contact pairs allow simultaneous control of mag lock de-energization and strike energization in a single device. Reduces wiring runs and simplifies the control schematic — fewer single-pole relays cascaded in series.
• Adjustable 1–60 Second Delay: On-site potentiometer adjustment means you're not locked into firmware timings. We've field-tuned this device to accommodate slow-moving populations (elderly care facilities) and fast egress requirements (security vestibules) without panel modification. The mechanical adjustment is intuitive for facility staff — turn the screw, test the door, repeat.
• 24VDC Direct Integration: Standard access control voltage — works with any hardwired or IP-based controller that outputs 24VDC momentary contact. No transformer, no voltage conditioning, no compatibility headaches.
• Compact Single-Gang Form Factor: Fits in narrow door frame cavities where a full-size relay module would require rework. Aluminum construction is durable in high-traffic environments; we've seen these devices survive impacts and rough handling better than plastic-housed alternatives.
• UL 294 & IBC Certification: Life-safety documentation is baked in — no argument with the AHJ on egress door control. We've used this device as the timing element in ADA-compliant request-to-exit circuits without design review delays.

Deployment Considerations:

• Pneumatic timing is mechanical, not digital — if you need to change the delay remotely or via software command, this is not the device. Verify that on-site adjustment (via technician visit) fits your operational model before specifying it into a multi-site installation.
• The 1–60 second range is fixed. If you need dwell times longer than 60 seconds (e.g., for multi-door man-trap sequences), cascade this device with a secondary timing relay or choose an electronic timer module instead.
• Temperature range −13°F to 158°F assumes indoor or climate-controlled outdoor mounting. In unheated vestibules or outdoor enclosures in cold climates, pneumatic response slows and may exceed the stated 60-second maximum. Test in your actual temperature environment before deploying across a large site.
• Wiring is straightforward (two white, two red DPST terminals), but verify your access control panel outputs true momentary contact on the strike line. If the panel energizes the strike continuously, the CM-7085 won't cycle properly — you'll need an intermediary relay to convert the panel's latch output to a momentary pulse.
• Service life of 1,000,000 cycles is typical; actual life depends on duty cycle and environmental contamination (dust, humidity in the pneumatic chamber). Budget for mechanical wear — the device is field-replaceable, but scheduling downtime for door control replacement requires facility coordination.
• Not suitable for outdoor weather-exposed mounting without an enclosure. Rain and moisture will damage the pneumatic mechanism. Use a NEMA 4X stainless steel wall mount if outdoor installation is required.

The CM-7085 is the right choice for integrators and facility managers who prioritize operational simplicity and electrical isolation over software flexibility. If your site has unreliable power, aging infrastructure, or regulatory requirements for mechanical fail-safe design, this device delivers. For modern campuses with stable 24VDC rails and centralized access control management, a networked electronic timer is likely more efficient. See the Camden catalog for alternative timing solutions.