Altronix AL400ULM 5-Output 12/24VDC Access Power Supply
The Altronix AL400ULM is a compact multi-output power distribution unit purpose-built for fire alarm and access control system integration. Operating from standard 115VAC mains input, the AL400ULM delivers selectable 12 or 24VDC output across five independent regulated circuits, each protected by individual PTC (Positive Temperature Coefficient) Class 2 fusing. This architecture means you get short-circuit protection on every output without managing traditional fuses—PTC devices self-reset after an overload clears, reducing service calls and downtime in the field.
Key Features
- Five PTC Class 2 regulated outputs: Each circuit has independent short-circuit protection and automatic recovery. You can push each output to its limit without worrying about a single fault cascading across your system.
- Selectable 12 or 24VDC output voltage: Single unit adapts to either voltage standard—no need to stock two SKUs. Select your voltage during installation based on your door lock, reader, and field controller specifications.
- Maximum output of 4A @ 12VDC or 3A @ 24VDC: Sufficient headroom for typical access control loads—multiple readers, electric strikes, maglocks, and auxiliary devices across five branches. At 24VDC, expect roughly 72W total system power; at 12VDC, up to 48W.
- Battery backup charging support: Integrated charging circuit prepares the unit to trickle-charge an external backup battery. Ensures your access control and fire alarm interfaces remain live during AC mains failure—critical for emergency egress and alarm signaling compliance.
- UL Listed certification: Meets safety and fire code requirements for commercial access control and life safety installations. Simplifies permit and inspection sign-off.
- Compact BC300 enclosure: Small form factor—fits standard electrical cabinet, rack, or surface-mount locations without consuming excessive panel real estate. Reduces installation labor compared to distributed power modules.
Integration & Compatibility
Deploy the AL400ULM wherever you need to consolidate auxiliary power for access control system devices. Typical integrations include door controllers, request-to-exit buttons, badge readers, electric strikes, magnetic locks, and fire alarm relay modules. The five independent circuits allow you to isolate critical loads—for example, emergency egress on one circuit, standard access on another—ensuring that a fault on one door lock does not starve power from life-safety devices.
The unit accepts standard 115VAC mains and requires no external power supply; output voltage is field-selectable, so you configure the AL400ULM once and it adapts to your voltage architecture. When paired with an external backup battery and charger module (not included), it delivers emergency power continuity during AC loss—essential for maintaining access control during power events and supporting fire alarm signaling requirements.
For large-scale deployments or systems requiring higher total current capacity, consider access control power infrastructure options from the Altronix catalog. Consult your access control system design guide to determine the number and capacity of power supplies your topology requires.
Frequently Asked Questions
Q: Can the AL400ULM supply power to both 12VDC and 24VDC devices simultaneously?
A: No. The output voltage is selected at configuration time and applies to all five circuits. If your system requires both voltage standards, you will need separate power supplies for each standard.
Q: What external battery specifications does the AL400ULM support for backup operation?
A: The AL400ULM has an integrated battery charging circuit but does not include a battery. Consult the product datasheet and your system integrator for approved battery types, ampere-hour ratings, and connection procedures to ensure safe backup operation and compliance with fire code.
Q: Does the AL400ULM include a battery charger or backup power in the box?
A: The AL400ULM includes the charging circuit but not an external battery or dedicated charger module. These are supplied and configured separately according to your backup runtime and load requirements.
Q: Is the AL400ULM suitable for outdoor installations?
A: The AL400ULM is rated for indoor use within the BC300 enclosure. For outdoor or harsh-environment access control power, consider a NEMA 4X or IP66-rated outdoor power supply enclosure.
Q: How do I size the external backup battery for the AL400ULM?
A: Battery capacity depends on your system load and required backup runtime (typically 4–24 hours for access control and fire alarm compliance). Work with your integrator to calculate total circuit current draw and select an appropriate UPS or standby battery module.
Q: What is the warranty on the AL400ULM?
A: The AL400ULM includes a Lifetime Limited Warranty covering defects in materials and workmanship under normal use conditions.
Ted PerryPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The Altronix AL400ULM occupies a specific niche: distributed access control power consolidation in cabinet-mounted or surface-mounted installations. Its five PTC Class 2 outputs mean you avoid the service call headache of traditional fuses—overloads reset automatically once the fault clears. This matters in multi-door systems where a single shorted reader or strike solenoid shouldn't trigger a facility callback.
Technical Highlights:
- 4A @ 12VDC or 3A @ 24VDC maximum output: Sufficient for typical five-door access control branches running electric strikes, maglocks, request-to-exit buttons, and badge readers. Do the math on your load profile before deployment—if you're pushing all five circuits to near-maximum, thermal dissipation in the compact BC300 enclosure becomes a real concern, especially in warm installations.
- PTC Class 2 self-resetting protection on all five circuits: Eliminates fuse inventory and reduces MTTR (mean time to repair). A blown fuse becomes a 30-second auto-reset instead of a service technician visit.
- Selectable 12 or 24VDC in one SKU: Flexibility for integrators managing mixed voltage estates, but remember—the choice is made at installation time. You cannot switch voltage mid-deployment without powering down.
- Battery backup charging support: The unit is ready to trickle-charge an external standby battery, enabling emergency power hold-up. Without external battery and charger modules (sold separately), the AL400ULM offers no backup capability—AC loss means access failure.
Deployment Considerations:
- The AL400ULM is strictly 115VAC mains input—no 240V or international voltage support. If your facility has 240V only, you'll need a step-down transformer or a different supply topology.
- Five circuits sounds like a lot until you audit a real multi-door site. Each circuit handles one primary device (strike, maglock, reader) plus maybe one auxiliary load. In a ten-door suite, you'll need two AL400ULM units, which complicates monitoring and maintenance.
- The compact BC300 enclosure keeps installation footprint small, but it also means thermal headroom is limited. In hot server rooms or non-climate-controlled closets, sustained full-load operation may cause stress on components. Verify airflow and temperature ratings before mounting.
Deploy the AL400ULM in single-building access control consolidation points—electrical rooms, IDF closets, or control cabinet installations where you're feeding multiple doors from one local hub. Its Lifetime Limited Warranty and UL listing make it suitable for life-safety integrations, but always pair it with backup power planning and thermal load analysis during site survey.
