Altronix AL300ULPD4CB UL-Listed 2.5A Power Supply with 4 PTC Outputs
Overview
The Altronix AL300ULPD4CB is a UL-listed, multi-standard compliant 12VDC or 24VDC power supply delivering 2.5 amps of regulated output across four independently protected PTC circuits. Built to satisfy the access control, fire, and security alarm agency requirements that installers encounter on commercial and institutional projects, this unit carries UL 294, UL 603, UL 1069, UL 1481, and CSA C22.2 No.205 listings — meaning a single supply can serve diverse low-voltage device loads across disciplines without requiring separate sourced hardware for each application. For integrators working on surveillance and access power supplies or multi-system installs, having that breadth of approvals in one enclosure simplifies both the design submittal and the inspection conversation.
Housed in a lockable steel enclosure measuring 13.5" x 13" x 3.25", the AL300ULPD4CB runs from 115VAC/60Hz and draws no more than 3.5 amps at the input — protected by a matched 3.5A/250V fuse. The output is selectable between 12VDC and 24VDC, which means the same unit stocks correctly for either camera voltage or lock voltage requirements depending on how the job is configured. Explore the broader Altronix power solutions line if you need higher current or additional output channels for larger deployments.
Key Features
- Selectable 12VDC or 24VDC Output: A single SKU covers both common low-voltage device standards — 12V for most IP cameras and door controllers, 24V for many locks and access panels. You don't need to commit to one supply per voltage rail when a mixed system is on the drawing board.
- 2.5A Regulated Output: Supports a realistic load budget for a cluster of cameras, readers, or alarm devices without tripping protection. At 12V, that's 30W available — enough for three to four typical 802.3af-class loads when combined with a PoE switch, or several direct 12VDC devices on their own circuits.
- Four Independent PTC (Poly-Switching) Output Circuits: Each output is individually protected by a resettable PTC device rather than a fuse. A shorted or overloaded field run trips only that circuit; the others keep running. The PTC resets automatically once the fault clears — no service call to swap blown fuses, which matters in unmanned equipment rooms.
- Form C AC Fail Supervision: The unit provides a Form C dry-contact relay output for AC loss, which wires directly into alarm panels or access control hardware. Any break in mains power generates a tamper-level signal before battery exhaustion becomes a problem — critical for UL-listed alarm applications where panel supervision is a listed-system requirement.
- Form C Low Battery and Battery Presence Supervision: Two additional Form C contacts monitor battery state independently — one flags a degraded battery under load, the other signals if the battery is absent entirely. On sites with annual life-safety inspections, these contacts close the audit loop without requiring a technician to manually test the standby plant.
- 0.7A Maximum Charge Current: The onboard charger is sized to maintain sealed lead-acid standby batteries without overcharging. At 0.7A maximum, it's compatible with standard 7Ah to 12Ah SLA batteries commonly paired with power supplies in this class — confirm battery compatibility against Altronix published battery tables for your specific standby runtime calculation.
- UL 294 / 603 / 1069 / 1481 and CSA C22.2 No.205 Listed: Multi-standard listing is the specification that actually determines whether an AHJ will sign off on the installation. UL 294 covers access control, UL 603 and 1481 cover intrusion/burglar alarm power, and UL 1069 covers hospital signaling — this supply satisfies the submittal requirement across all four without substitution.
- 0°C to 49°C Operating Range: Covers conditioned equipment rooms and most North American indoor-only enclosures. This is not a rated outdoor or extreme-environment unit — don't install it in an unheated mechanical room in a cold climate without verifying ambient temps stay within range year-round.
Integration & Compatibility
The AL300ULPD4CB is designed to serve as the power backbone in access control and security alarm head-end enclosures. The Form C supervision outputs are compatible with virtually all major access control panels that accept dry-contact zone or tamper inputs — wire AC fail to a 24-hour supervision zone and the two battery contacts to separate monitoring zones per your panel's requirements. The 12VDC/24VDC selectable output pairs with electric strikes, maglocks, door controllers, PIR detectors, and IP cameras that accept direct-wire DC power rather than PoE. For camera-only deployments requiring PoE delivery, pair this supply with a compatible PoE switch or midspan injector — this unit provides the DC rail for the switch or other ancillary loads, not PoE itself. Battery backup integration follows standard SLA chemistry connections; consult Altronix standby battery selection guides for runtime sizing against your device load and required holdover duration.
Frequently Asked Questions
Q: What UL listings does the AL300ULPD4CB carry?
A: The AL300ULPD4CB is listed under UL 294 (access control), UL 603 (protective signaling), UL 1069 (hospital signaling), UL 1481 (burglar alarm), and CSA C22.2 No.205. This multi-standard listing makes it acceptable for use across access control, intrusion, and alarm applications without requiring separate supplies per discipline.
Q: Can the AL300ULPD4CB output both 12V and 24V simultaneously?
A: No. The output voltage is selectable — either 12VDC or 24VDC — not simultaneously on both rails. Configure the output voltage at installation time based on your device load requirements.
Q: What does PTC output protection mean in practice?
A: PTC (Poly-Switching Thermal) devices are resettable overcurrent protectors. If a field circuit is shorted or overloaded, only that circuit's PTC trips. The remaining three outputs continue operating unaffected. Once the fault is cleared, the PTC resets automatically — no fuse replacement required.
Q: What size battery does this power supply support?
A: The onboard charger delivers a maximum of 0.7 amps, making it compatible with standard sealed lead-acid (SLA) batteries in the 7Ah to 12Ah range typically used for standby power in this supply class. Confirm specific battery compatibility and runtime calculations using Altronix's published battery selection tables.
Q: What are the enclosure dimensions and weight of the AL300ULPD4CB?
A: The enclosure measures 13.5" wide x 13" high x 3.25" deep and weighs 8.45 lbs. Shipping weight is 9.35 lbs.
Q: What temperature range is the AL300ULPD4CB rated for?
A: The unit is rated for operation between 0°C and 49°C (32°F to 120°F). It is designed for conditioned indoor environments — not suitable for unheated or outdoor enclosures where ambient temperatures may fall below freezing.
The AL300ULPD4CB earns its place in multi-discipline commercial installs because of those five agency listings — UL 294, 603, 1069, 1481, and CSA C22.2 No.205 — packed into a single 13.5" x 13" enclosure. When you're pulling permit on a project that mixes access control hardware with intrusion detection and possibly hospital-grade signaling, having one supply satisfy all the AHJ checkboxes saves both shelf space in the head-end cabinet and the argument with the inspector about using a non-listed supply for a listed application.
Technical Highlights:
- Four Independent PTC Outputs: Each of the four circuits resets automatically after a fault clears — no truck roll to swap fuses on a field short. Critical on multi-door access installs where losing all output power to clear one bad run is not acceptable.
- Three-Contact Supervision (AC Fail + Low Battery + Battery Presence): All three Form C outputs wire into alarm panel zones, giving you granular fault reporting without additional monitoring hardware. Most competitive supplies include AC fail only; the battery presence contact is the one that catches a missing battery before a power test exposes a standby hole.
- 0.7A Maximum Charge Current: Correctly sized for 7–12Ah SLA batteries — aggressive enough to recover charge within a reasonable window without stressing the battery. Don't pair this with large-capacity batteries expecting fast recovery after an extended outage; the math won't work for overnight runtime requirements without a larger charger.
Deployment Considerations:
- The 3.5A input fuse is not field-replaceable by design — if the input fuse blows, that's a symptom of a wiring or fault condition upstream that needs diagnosis before the supply goes back in service. Plan your circuit protection at the panel accordingly.
- The 0°C minimum operating temperature is the spec that catches installers on cold-climate projects. A garage or unheated stairwell in the northern US can easily drop below 0°C in winter — if your install location isn't continuously heated, this unit is the wrong choice regardless of its listing credentials.
Deploy the AL300ULPD4CB as the supervised power head-end in commercial office or healthcare access control panels where the AHJ requires multi-standard UL listing, independent circuit fault isolation, and documented battery supervision on the inspection checklist.
