Altronix RB524 24VDC DPDT Relay Module
The Altronix RB524 is a dual-pole, dual-throw relay module engineered for switching and control applications in security infrastructure. Built around a 24VDC control input, the RB524 delivers two independent switching circuits, each rated for 5A maximum current. This capacity covers the majority of door strikes, magnetic locks, and auxiliary control loads found in access control and alarm signaling deployments. The module supports both 220VAC and 28VDC output switching, making it compatible with legacy and modern power supplies in the same installation.
Key Features
- 24VDC Control Input: Integrates directly with standard security system power supplies and control panels, eliminating the need for separate power conditioning or signal isolation circuits.
- DPDT Configuration (2 Independent Circuits): Two separate relay contacts allow simultaneous control of two different loads—such as a door strike on one circuit and an alarm relay on the second—without cross-talk or shared logic.
- 5A Maximum Per Circuit: Sufficient capacity for standard door strikes (typically 0.5–2A) and medium-duty solenoids, reducing the need for auxiliary contactors in smaller deployments.
- 220VAC and 28VDC Output Support: Flexibility to switch either mains AC voltage for legacy buzzers and signaling devices, or 28VDC for modern access control hardware, within the same relay module.
- Compact DIN Rail or Panel Mounting: Fits standard DIN rail enclosures or direct panel termination, reducing footprint in crowded equipment cabinets and simplifying retrofit installations.
- Lifetime Limited Warranty: Manufacturer-backed coverage provides long-term support for critical control logic in 24/7 security systems.
Typical Applications
Access control systems often require auxiliary relay logic to sequence door strikes, mag locks, and alarm outputs. The RB524 handles dual-load switching without the cost and complexity of programmable relays. Alarm systems use the DPDT configuration to trigger both a door release and a notification relay simultaneously. HVAC and facility automation in security installations frequently depend on simple, reliable relay modules to manage damper controls or fan activation tied to access events or alarm states. Warehouse automation systems that integrate security checkpoints benefit from the 5A capacity and voltage flexibility when coordinating gate locks, loading dock doors, and warning lights.
Integration Considerations
The RB524 is designed as a standalone switching component and does not require software configuration. Wiring is straightforward—24VDC control signal in, switched output voltage (220VAC or 28VDC) to the downstream load. In large security control systems, ensure the 24VDC supply feeding the relay has adequate reserve capacity; each RB524 control coil draws current proportional to its duty cycle. Verify that the output voltage (220VAC or 28VDC) is pre-selected and stable before commissioning the module. When switching inductive loads such as solenoids, consider adding transient protection (diodes or varistors) across the load terminals to prevent relay contact degradation over extended cycles.
Frequently Asked Questions
Q: Can the RB524 switch both 220VAC and 28VDC simultaneously?
A: No. The module is configured for one output voltage at installation—either 220VAC or 28VDC. Both circuits within the RB524 switch the same output voltage. If your deployment requires both AC and DC switching, you would need two separate RB524 modules.
Q: What control voltage does the RB524 require?
A: The RB524 operates on 24VDC control input. This is the standard voltage for most security system power supplies and access control panels, making it a direct fit for existing infrastructure.
Q: Is the RB524 suitable for high-cycle solenoid or strike applications?
A: Yes, within the 5A per-circuit limit. Standard electromagnetic door strikes draw 0.5–2A at 24VDC or 28VDC, well below the RB524 rating. Magnetic locks typically draw 0.6–1.5A. For loads exceeding 5A, consider a contactor-based solution or multiple relays in parallel.
Q: Does the RB524 include terminal blocks or require soldered connections?
A: The module is designed for DIN rail or panel mounting with fixed terminal connections; refer to the datasheet for exact wiring specifications and terminal compatibility.
Q: What is the lifetime warranty coverage?
A: Altronix provides a Lifetime Limited Warranty on the RB524, covering defects in materials and workmanship under normal use. Refer to Altronix warranty documentation for exclusions and claim procedures.
Jerry TildsenPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The Altronix RB524 is a straightforward, no-frills dual-relay module that solves a real problem in access control and alarm system wiring: you need two separate switching circuits, each carrying moderate current (door strike + solenoid lock, or mag lock + signaling relay), and you want them from the same control signal. The RB524 delivers exactly that—24VDC control in, two independent 5A circuits out, no programming overhead.
Technical Highlights:
- DPDT Topology (2 Isolated Circuits): Each relay operates independently. A fault or load spike on one circuit does not affect the other, which matters when you're driving a door strike and an audio alarm from the same control event.
- 5A Per Circuit: Covers nearly all standard door strikes (0.5–2A), magnetic locks (0.6–1.5A), and small solenoid valves. If you're running loads above 5A per circuit, you need a contactor, not a relay module.
- 24VDC Control + 220VAC / 28VDC Output Flexibility: The control input is always 24VDC (standard for security panels and power supplies). The output can be configured for either 220VAC (legacy buzzers, strobes) or 28VDC (modern access control hardware). Choose one output voltage at installation—you cannot mix AC and DC on the same module.
Deployment Considerations:
- Output Voltage Is Fixed at Installation: You commit to 220VAC or 28VDC when you wire the module. If your next project requires the opposite voltage, you'll need a second RB524 or a different relay type. This is not a limitation—it's a design choice that simplifies wiring—but confirm your output voltage requirement before you build the cabinet.
- Inductive Load Transients: If you're switching solenoids or mag locks, those devices generate back-EMF spikes when de-energized. A standard diode (1N4007 or similar) across the load terminals protects the relay contacts from pitting. This is good practice regardless of the relay brand, and it extends contact life from hundreds of cycles to thousands in high-traffic access points.
- Control Coil Current Draw: The 24VDC control circuit draws modest current when the relay is energized. In battery-backed or solar-powered security systems, verify that your 24VDC power supply has headroom for multiple RB524 modules if you're daisy-chaining them.
The RB524 is the right choice when you need bulletproof dual-load switching in a compact footprint—fire doors with simultaneous strike and alarm relay, multi-point entry systems, or HVAC tie-ins where you route control to two separate damper coils from one access event. It's not a smart relay (no logic, no programming), and it's not a contactor (5A ceiling), but it is rock-solid for the mid-range switching tasks that fill most access control cabinets.
