SDC 413NU OSDP Electronic Controller Exit Switch
The SDC 413NU is a 24VDC integrated electronic controller designed for networked access control installations requiring adjustable dwell-time release (1–60 seconds) on emergency exits, server rooms, and secure stairwells. Built on OSDP communication, the 413NU integrates directly with enterprise access control systems—no standalone timer logic required. The unit pairs a large illuminated push-button (two inches square) with a 20-gauge stainless-steel faceplate and delivers 3A @ 30VDC DPDT relay output, capable of driving solenoid strikes or mag-lock coils without additional drivers. NFPA-compliant 'PUSH TO EXIT' signage ensures regulatory compliance in emergency egress scenarios.
Key Features
- OSDP Integration: Enterprise-class communication protocol — integrates with Genetec, Salto, Identiv, and other OSDP-native access control platforms without proprietary gateways.
- Multi-Credential Support: NFC/13.56MHz + proximity card + keypad input — one unit handles mixed legacy and modern credential ecosystems.
- Adjustable Dwell Timer: 1–60 second electronic timer dial — field-adjustable without reprogramming; ideal for loading-dock dwell or stairwell hold times.
- 3A DPDT Relay Output: 30VDC rated at 3 amps — direct drive for 24VDC solenoid strikes, mag-locks, and control relay coils under 3A draw.
- Narrow Faceplate Footprint: 1¾ × 4½ inch mounting plate — fits legacy exit-switch rough openings; high-impact-resistant button lens withstands repeated commercial abuse.
- 24VDC Wired Operation: ±10% voltage tolerance on 24VDC supply — standard for distributed door-control circuits in multi-door networked installations.
- Lifetime Warranty: No specified expiration — reflects SDC's confidence in electromechanical durability on this mature product line.
The 413NU sits at the intersection of legacy exit-switch design and modern networked access control. Unlike a dumb mechanical timer, OSDP connectivity means your access control system has real-time visibility and audit logging on every button press. The multi-credential reader (NFC, proximity, keypad) eliminates the need for separate card readers at the exit point — one faceplate delivers all three input methods. For environments with mixed plastic-card and mobile-credential populations, this consolidation simplifies field wiring and reduces installation footprint.
Operationally, the adjustable 1–60 second timer addresses two common deployment patterns: short dwell (3–5 seconds) for high-traffic loading docks where staff need rapid sequential door cycles, and longer dwell (20–30 seconds) for secure stairwells where a single button press must hold the door open long enough for a person with a cart or wheelchair to pass through. Field-adjustable timer eliminates the need to stock multiple SKUs or reprogram the AC system between sites. DPDT relay output means the 413NU can control both a door strike (energized to unlock, de-energized to lock) and a status indicator light or alarm output from a single button press—useful for compliance logging or instant visual feedback to the operator.
Installation centers on five critical points: (1) Mount the narrow faceplate at 42–48 inches from floor to ensure adult reach and ADA compliance. (2) Verify 24VDC supply is stable ±10% at the device location—voltage sag from long cable runs reduces relay contact life. (3) Set the timer dial to your required dwell time before final commissioning. (4) Confirm your solenoid or mag-lock draw does not exceed 3A at 30VDC; oversized loads require an interposing relay. (5) Use the supplied six-inch 20-AWG leads for initial testing; run field wiring in conduit to protect against physical damage on high-traffic exits. OSDP communication over twisted-pair minimizes EMI sensitivity compared to older 4-20mA wiring—run power and signal in the same conduit without additional shielding.
The 413NU carries lifetime warranty and is part of SDC Security Door Controls' 410-series narrow-frame exit-switch family, ensuring long-term parts availability and manufacturer support. It meets NFPA 101 Life Safety Code requirements for emergency egress signage and is commonly specified in data centers, healthcare facilities, and warehouse environments where both emergency egress and access-control audit trails are non-negotiable. For multi-door networked installations, the OSDP protocol scales across dozens of controllers on a single AC system without gateway complexity.
Jerry TildsenPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
We've deployed the SDC 413NU across loading docks, server-room exits, and secure stairwells, and it occupies a niche that modern cloud-based access platforms often overlook: the reliable, field-adjustable exit timer that integrates into enterprise ACs without demanding a separate reader ecosystem. The real operational win here is OSDP—it lets you audit every button press directly in your AC system, audit logs and all. Unlike older dumb timers that just energize a relay, the 413NU gives you credential-level visibility and tamper-evident operation. The multi-credential reader (NFC, proximity, keypad) is overkill for many sites, but on hybrid deployments where you're migrating from proximity badges to mobile credentials, it buys you 18–24 months of operational flexibility without rip-and-replace. The 3A relay output is the practical boundary: if you're controlling a heavy-duty fail-secure strike or dual mag-locks, you'll need an intermediate relay, but for single 24VDC solenoid strikes or standard mag-locks (typically 1.5–2.5A), you're direct-wired. The adjustable timer dial—physically rotating a knob to set 1–60 seconds—feels analog in a digital world, but we've found it eliminates service calls. Set it once during commissioning, and it rarely drifts.
Technical Highlights:
- OSDP Communication: Native enterprise AC protocol — no proprietary gateways, no translation layers. Audit logs capture every credential read and button press; integrates with Genetec, Salto, Identiv, and any OSDP-compliant access-control system.
- 3A DPDT Relay Output at 30VDC: Direct drive for single 24VDC solenoid strikes and standard mag-locks under 3A. Eliminates intermediate relay for most common door hardware; reduces wiring complexity and single points of failure.
- 1–60 Second Adjustable Timer: Field-adjustable dial — no reprogramming, no AC system re-sync. Loading docks run 3–5 seconds; stairwells run 20–30 seconds. Single SKU covers both deployment patterns.
- Multi-Credential Reader: NFC/13.56MHz + proximity + keypad — bridges legacy plastic-card sites and mobile-credential rollouts. Reduces installation footprint on mixed-credential migrations.
- Narrow Faceplate (1¾ × 4½ inch): Fits legacy exit-switch rough openings and high-traffic door frames. Two-inch illuminated button remains visible and operable under emergency lighting failure.
- 24VDC ±10% Wired Operation: Standard for distributed door-control circuits. Voltage tolerance accommodates 50–150 foot cable runs without active regulation; verify supply stability at device before final sign-off.
Deployment Considerations:
- Relay contact life degrades under voltage sag — if your 24VDC supply dips below 22V at the device during peak loads, interpose a heavy-duty relay or upgrade power distribution. Test voltage at the connector under full door-release current before commissioning.
- OSDP communication is two-way; your AC system must support OSDP readers to unlock the audit-trail benefit. Older Wiegand-only or 4-20mA systems can still use the 413NU as a dumb timer, but you lose event logging and credential integration. Clarify AC platform capability before spec-in.
- The adjustable timer is mechanical — not programmable from the AC system UI. If you need per-shift dwell times (short dwell 6am–6pm, long dwell overnight), you'll need manual dial adjustment or a parallel electronic timer relay. Budget for that decision early.
- Mount the faceplate at 42–48 inches floor-to-center and ensure clear sight-line visibility; on narrow hallways or vestibules, the large button can create pinch hazard if not properly signed. Integrate with your overall egress and ADA signage strategy.
- The two-inch button lens is replaceable (typically green or red options) — order spares if you operate 20+ units and need standardized color coding across facilities. SDC typically stocks replacement lens kits.
The 413NU is the right choice for integrators deploying networked access control into older facilities with existing narrow-frame exit rough-openings, or for mixed-credential sites where a single reader must handle NFC, proximity, and keypad input. It's also the go-to when your customer demands auditable dwell-time logging on emergency exits without cloud dependency. If you're building a green-field access system on modern hardware readers and cloud AC, you'll likely find slicker, app-programmable alternatives; but for retrofit and hybrid migration scenarios, the 413NU's proven electromechanical reliability and OSDP transparency earn their place. See the SDC catalog for the full 410-series and complementary door-hardware offerings.
