Altronix RDC12 12VDC DPDT Relay Base Module
The Altronix RDC12 is a compact electromagnetic relay module engineered for 12VDC control applications across security and access infrastructure. This unit delivers a single DPDT (Double Pole Double Throw) relay capable of 10A switching at 220VAC or 28VDC, making it suitable for door strike control, alarm signal routing, camera power failover, and HVAC interlocks. UL recognition confirms compliance with safety standards for installations where documented approval matters.
Key Features
- 12VDC Input Voltage: Operates from standard 12VDC power supplies or backup battery systems, eliminating the need for AC-to-DC conversion in most security control cabinets.
- 10A Maximum Current Rating (220VAC / 28VDC): Sufficient to switch moderate-load circuits such as electric strikes, siren outputs, or multi-camera power distribution without additional external contactors in many deployments.
- Single DPDT Relay Configuration: Two independent changeover contacts allow simultaneous control of two separate circuits or selection logic — one circuit energized while the other de-energizes, useful for failover or load-sharing scenarios.
- UL-Recognized Construction: Third-party safety agency approval reduces liability risk in commercial and institutional security projects where code compliance and insurance underwriting are factors.
- Compact Base Module Form Factor: Fits standard 35mm DIN rail mounting, preserving enclosure space in crowded control panels.
- Lifetime Limited Warranty: Long-term coverage against manufacturing defects; review the full warranty terms for exclusions and support conditions.
Integration & Compatibility
The RDC12 integrates into security control systems via 12VDC coil control lines from access control panels, alarm processors, or camera management systems. The relay provides galvanic isolation between the control circuit (low-current logic level) and the load circuit (higher current switching), protecting sensitive electronics from inductive kickback and preventing ground loops.
Typical deployments pair the RDC12 with power supplies (such as Altronix power infrastructure products) to manage electromagnetic locking devices, siren circuits, or switched camera feeds. The module mounts on standard access control enclosures and works with both legacy and modern IP-based alarm systems that output 12VDC relay trigger signals.
For large-scale switching requirements (e.g., multiple door strikes, complex failover logic), evaluate higher-capacity relay modules or industrial contactors in the same family.
Deployment Considerations
The 10A limit at 220VAC/28VDC is not negotiable — oversizing the load will damage the contacts. Verify actual inrush current during door strike release or motor startup; inductive loads may draw significantly higher transient current than steady-state rating. Install a varistor or diode clamp across inductive loads (coils, solenoids) to suppress voltage spikes that can degrade contact life.
Door strike circuits commonly draw 6–8A in pull-to-lock mode, leaving margin, but confirm your specific strike specification. If you require hot-standby switching or need the relay to respond in sub-second intervals, test the contact bounce characteristics with your control system logic.
Frequently Asked Questions
Q: Can the RDC12 control both a door strike and a siren simultaneously?
A: Yes — the DPDT configuration allows two independent circuits. One NO (normally open) contact can energize the strike; the other NO contact can energize the siren. Both operate when the 12VDC coil is powered, or you can wire them for selective logic using the NC (normally closed) contacts.
Q: What is the coil voltage — is it fixed at 12VDC?
A: Yes, the RDC12 coil operates at 12VDC only. Do not apply higher voltages to the coil; use a regulated 12VDC power source.
Q: Is the RDC12 compatible with my existing access control system?
A: If your system outputs a 12VDC relay trigger, yes. Confirm your panel's output is 12VDC and that the signal can drive a low-impedance relay coil. ONVIF-compliant IP systems may require a separate relay interface module.
Q: What mounting options are available?
A: The RDC12 is a base module designed for 35mm DIN rail mounting inside standard electrical enclosures. Surface mounting or panel mounting is not supported by this form factor.
Q: Does the RDC12 include a manual override?
A: No — this is a passive relay module without a mechanical override button. Control is 12VDC coil-driven only.
Ted PerryPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The RDC12 is a workhorse relay module for 12VDC control circuits — exactly what you need when an access panel or alarm processor must trigger a higher-current load like a door strike or failover circuit. The 10A rating at 220VAC/28VDC gives you real switching headroom without oversizing your enclosure.
Technical Highlights:
- DPDT Configuration (Two Independent Contacts): You get two changeover pairs from a single relay. This means simultaneous control of two separate circuits — energize a strike on one contact, energize a monitor circuit on the other, or wire them for logical selection. That flexibility beats single-pole designs in multi-load scenarios.
- 10A @ 220VAC/28VDC Switching Capacity: Standard door strikes run 6–8A steady-state; siren circuits often draw less. The 10A rating gives you a safety margin without forcing you into larger industrial contactors. For comparison, undersized relays fail prematurely from contact erosion on inductive loads.
- UL Recognition: Third-party approval means faster permit sign-off and no pushback from jurisdictional inspectors on commercial builds. It also signals that the relay coil, switching mechanism, and mechanical robustness have been tested to recognized standards.
Deployment Considerations:
- Coil voltage is fixed at 12VDC — confirm your control source delivers regulated 12VDC before wiring. Fluctuating or unregulated supplies will cause chatter and premature contact wear.
- The single biggest gotcha: inductive load clamping. Door strikes, solenoid locks, and buzzers generate voltage spikes when the relay contact opens. Those spikes will pit the contact surfaces and degrade switching reliability. Always install a 1N4007 diode across inductive loads (cathode to positive, anode to ground). Neglecting this can cut relay life from years to months.
- Confirm contact bounce characteristics with your logic controller. Most modern alarm systems tolerate a few milliseconds of bounce, but edge-triggered systems may miss the event. Bench-test before final deployment.
For access control retrofits where you need to add a remote door strike or battery backup siren to an existing panel, the RDC12 is the standard choice. Its compact footprint and dual-contact flexibility make it far more practical than running a separate relay module for each circuit. Size your supply for the total steady-state load plus 50% margin for transients, and you'll have a rock-solid installation.
