Altronix LPS3WP24 24VDC Linear Power Supply
The Altronix LPS3WP24 is a single-output 24VDC linear power supply engineered for access control and security installations where clean, regulated DC power is essential. Operating from standard 115VAC input, it delivers a stable 24VDC output with built-in AC fail supervision—a feature that monitors line power integrity and alerts the system to brownouts or complete outages before they cascade into door lock failures or reader lockups. The linear topology (as opposed to switch-mode designs) produces minimal electrical noise, reducing EMI-induced false triggers on proximity readers and card scanners. This makes the LPS3WP24 a pragmatic choice for smaller deployments where a handful of locks and readers share a single power rail.
Key Features
- Single 24VDC output with voltage regulation: Maintains stable 24V within tolerance, protecting electromechanical locks and solid-state readers from voltage sag or overshoot that can shorten component life or cause erratic operation.
- AC fail supervision: Detects loss of input AC power and generates an alarm or supervisory signal—critical for door access audits and compliance reporting. You know immediately when the wall outlet goes dark.
- Linear design for low-noise DC: Eliminates the high-frequency switching noise common in switch-mode supplies, which can couple into adjacent card reader antenna circuits and trigger phantom reads.
- 115VAC input compatibility: Standard North American wall power; no step-down transformer or voltage converter needed. Straightforward wiring to a dedicated breaker.
- Compact form factor: Fits standard DIN-rail enclosures or wall-mounted cabinet installations. Small footprint reduces panel real estate consumption in retrofit access control cabinets.
- Lifetime limited warranty: Manufacturer-backed coverage reflects confidence in the linear architecture, which has fewer failure modes than switch-mode equivalents.
Deployment Context
The LPS3WP24 is purpose-built for small to mid-sized access control nodes—think a single door with an electric lock, card reader, and request-to-exit sensor, or a small office vestibule with two readers and a strike. It delivers clean power to door strikes (typically 400–600 mA draw), magnetic locks at idle, proximity card readers (50–200 mA typical), and auxiliary control relays. The 0.5A maximum output at 12VDC is conservative; at 24VDC the supply can support multiple door control devices if their combined current stays within the rated envelope—check your bill of materials current draw before deployment.
The AC fail supervision output is wired to an access control panel's power monitoring input. This supervisory feedback allows the panel to log power events, trigger a siren or strobe, or unlock all doors on standby power when mains AC fails—depending on your system's programming. Without supervision, a blown fuse at the supply is silent; with it, you get immediate notification.
Integration & Compatibility
The LPS3WP24 integrates with any access control panel or standalone relay module that accepts 24VDC. Output connections are screw-terminal; standard practice is to run 18 or 16 AWG twisted pair from the supply to the furthest device, then daisy-chain secondary devices if cable length allows. For longer runs (over 100 feet) or high-current aggregates, consider a dedicated panel-mount supply per door or node to minimize voltage drop. The AC fail supervision line (typically a dry contact or active signal) connects to the panel's DC loss input—consult your panel's wiring manual for pinout.
When to Choose a Different Model
If you need a redundant or backup power supply (e.g., a second supply running in parallel for high-availability installations), or if you require higher current output for a multi-lock application, consult the broader Altronix power supply family, which includes higher-capacity and multi-output variants. The LPS3WP24 is intentionally single-channel and entry-tier—it prioritizes simplicity and reliability, not feature density.
Frequently Asked Questions
Q: What's the maximum combined current the LPS3WP24 can deliver?
A: The supply is rated for 0.5A maximum output at 12VDC. At 24VDC (the nominal output), you can safely provision up to 0.5A continuous draw across all connected devices. Exceeding this triggers current limiting or causes the supply to shut down to protect internal components.
Q: Does the LPS3WP24 work with both 115VAC and 230VAC?
A: No, the LPS3WP24 is 115VAC only. If you need 230VAC compatibility (common in international or industrial sites), contact the manufacturer or your system integrator for a multi-input variant.
Q: Can I mount the LPS3WP24 inside a standard door access control cabinet?
A: Yes. The compact form factor and DIN-rail compatibility allow installation in most enclosures. Ensure adequate ventilation—a clear 2-inch margin around the supply reduces thermal stress and extends service life. Linear supplies run warm under sustained load.
Q: What does AC fail supervision do?
A: The LPS3WP24 includes a dry contact or signal output that changes state when 115VAC input is lost or restored. This supervisory signal wires to your access control panel, which can then log the event, trigger an alarm, or switch to emergency unlock mode. It's an early-warning system for power anomalies.
Q: Is the LPS3WP24 suitable for outdoor installations?
A: The LPS3WP24 is designed for indoor cabinet or wall mounting. For outdoor door control (e.g., a gate or exterior reader), mount the supply inside a weatherproof junction box or cabinet, and run 24VDC wire to the outdoor devices using conduit or armored cable to prevent UV degradation and water ingress.
Q: What warranty does the LPS3WP24 carry?
A: Lifetime limited warranty. The manufacturer warrants the unit against defects in materials and workmanship for the life of the original purchaser. Check the warranty paperwork for exclusions (e.g., damage from misuse, overvoltage, or reverse polarity).
Ted PerryPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The Altronix LPS3WP24 is a straightforward, linear-topology power supply—no switching noise, no surprises. The key differentiator here is the AC fail supervision output. Too many small access control deployments lack any power monitoring, which means a blown fuse or tripped breaker silently disables doors until someone notices the card reader is dead. The LPS3WP24 addresses that gap without complexity.
Technical Highlights:
- Linear output architecture: Zero switching-mode noise means proximity readers and mag-lock solenoids operate without EMI-induced chatter or false triggers. Cleaner power translates to fewer nuisance lockouts and service callbacks.
- AC fail supervision: The dry contact changes state on power loss, feeding a logic input on your access control panel. You get immediate notification—no silent failures. Critical for compliance and audit trails.
- 0.5A @ 12VDC rating: Conservative rating, but honest. A typical electromagnetic strike draws 400–600 mA; a card reader, 80–150 mA. You can aggregate a strike, reader, and a relay output within budget, but don't assume unlimited capacity.
Deployment Considerations:
- Voltage drop over distance: If you're running 24VDC more than 100 feet to a remote door, pick 18 AWG twisted pair minimum and check the voltage at the lock. Undersized wire causes sag and erratic solenoid behavior.
- Single-output limitation: The LPS3WP24 is one rail of 24VDC. If you later add a second door or upgrade to a multi-reader node, you'll need a second supply or a larger cabinet-mount unit. Plan for growth when you spec the enclosure.
- Thermal headroom: Linear supplies generate heat under continuous maximum load. Leave 2–3 inches of clearance around the chassis. In a hot cabinet (summer outdoor installation), consider a supply with forced-air cooling or accept derated current output.
Position the LPS3WP24 in small single-door access nodes, kiosks, or gatehouse installations where simplicity and power monitoring are valued over feature breadth. It's not a Swiss Army knife—it's a purpose-built component that does one job reliably.
