Altronix ALTV248ULCBMI3 8-Output Isolated PTC Supply
The Altronix ALTV248ULCBMI3 is a compact auxiliary power supply designed for distributed power management in multi-device security systems. It provides eight electronically isolated 24VAC outputs, each protected by individual Positive Temperature Coefficient (PTC) fuses, eliminating the need for traditional glass or cartridge fuses on downstream circuits. Independent fault isolation ensures that a short or overload on one output does not cascade to adjacent channels, a critical requirement when powering mixed arrays of locks, sensors, strobes, and credential readers from a single supply point.
Key Features
- Eight Electronically Isolated Outputs: Each channel is electrically independent, allowing safe parallel connection of multiple 24VAC devices without cross-talk or load interaction.
- Individual PTC Circuit Protection: Positive Temperature Coefficient fuses automatically reset when fault current clears, eliminating service calls for blown fuses and reducing downtime on multi-channel deployments.
- Independent Fault Isolation: Short or overload on one channel does not interrupt power to the remaining seven outputs, preserving system operation during localized failures.
- 24VAC Input: Standard security system voltage — works with any 24VAC transformer or UPS-backed supply in the panel.
- UL Listed, CE Approved: Compliant with North American and European electrical standards for permanent installation in commercial security systems.
- Lifetime Limited Warranty: Factory-backed coverage reflects design maturity and manufacturing confidence in isolation and protection integrity.
The ALTV248ULCBMI3 solves a recurring integration challenge: powering a diverse mix of 24VAC ancillary devices (door locks, request-to-exit sensors, LED strobes, badge readers) from a single panel supply without sacrificing device-level protection or risking a single short-circuit taking down the entire auxiliary power tree. Traditional fused distribution blocks require technician intervention to swap failed fuses; PTC reset protection converts fault recovery to automatic, reducing mean time to restoration (MTTR) on 24-hour monitoring sites.
Isolation is the operational differentiator here. On a 16-door access control panel with eight door magnets, four electric strikes, and four request-to-exit buttons all powered from auxiliary supply, a corroded lock coil on door 3 creates a short that would trip a conventional single-fuse supply, killing power to all eight doors simultaneously. The ALTV248ULCBMI3 isolates door 3, allowing the other seven doors to remain powered while facilities dispatch a technician to the failed lock. Integration with commercial access control platforms (Salto, Gallagher, Honeywell Pro-Watch, etc.) is simplified because each output can be independently monitored and controlled via dry-contact relay feedback if needed.
The unit accepts a single 24VAC input and distributes it across eight isolated channels without step-down or conversion; bitrate and voltage remain constant across all outputs, making it compatible with any legacy or modern 24VAC device. Power budget is straightforward: aggregate the current draw of all downstream devices and confirm the supply can sustain the total load. The eight-channel isolation means you can tier load across outputs rather than designing a single oversized fuse for all devices, reducing panel clutter and improving maintainability on retrofit jobs.
Compliance with UL 508 (industrial control panels) and CE marking under EN 60950-1 ensures acceptance by code inspectors and integrators working in regulated verticals (healthcare, financial, government facilities). Lifetime warranty coverage reinforces the product's role as infrastructure-grade power distribution, not consumable equipment.
Marty AllisonPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
We've deployed the ALTV248ULCBMI3 across mid-to-large access control jobs where the client requirement is bulletproof auxiliary power distribution — hospitals, corporate campuses, retail chains with multiple building zones. The isolation topology is what separates this from a simple terminal block: each output sees its own protection curve, so a single high-inrush load (like a 24VAC solenoid on power-up) doesn't sag the bus voltage for the other seven channels. On a 32-door hospital installation we completed last year, the facility manager wanted to add badge readers and strobes to the existing strike power circuit. Rather than run new 24VAC runs from the main panel, we dropped in the ALTV248ULCBMI3 and isolated the lights from the locks — eliminated nuisance trips and gave them granular control over which devices had priority in a power-constrained panel. PTC reset behavior is a feature integrators often overlook: you don't need spare fuses in the van, and a customer callback at 2 a.m. for a blown fuse becomes a five-minute check-in instead of a parts run. That operational win compounds on large deployments.
Technical Highlights:
- PTC Positive Temperature Coefficient Protection: Self-resetting fuse technology eliminates glass-fuse inventory and repeat service calls. When fault current drops, the PTC automatically restores continuity — no technician intervention required. On a 10-location retail chain, that means one less SKU to stock and one fewer reason to call you back at midnight.
- Eight Independent Isolation Channels: Each output is electrically decoupled from the others, so a short on one lock coil doesn't ripple through the power distribution tree. Critical for mixed-load scenarios (locks + strobes + readers) where device impedance and inrush profiles vary widely.
- 24VAC In, 24VAC Out (No Voltage Drop): Direct isolation without buck-boost conversion means your downstream devices see clean, stable 24VAC across the entire load range. No nuisance door strikes, no flickering strobes, no credential reader timeouts due to brownout.
- Compact Form Factor: Approximately 1 lb, designed to mount inside standard 24VAC power-distribution or access-control enclosures. Saves panel real estate versus eight individual DIN-rail fuse holders.
- UL 508 + CE Compliance: Acceptable in North American and EU electrical code environments without additional certification paperwork. Simplifies specifying for global integrators or clients with multi-jurisdictional sites.
Deployment Considerations:
- PTC reset time is typically 1–10 seconds depending on fault severity; if you have devices that cannot tolerate brief power dips, size the downstream load to avoid repeat thermal cycling on the PTC elements. High-inrush solenoids (like 24VAC door strikes) may benefit from a small series inductor or soft-start module if the panel supply is undersized.
- The unit is a 24VAC pass-through isolation device only — it does not regulate, step down, or provide battery backup. Confirm your 24VAC supply can sustain peak current across all eight outputs simultaneously, or use load-shedding logic in your control system to sequence high-inrush devices.
- Input is a simple 24VAC 3-wire line cord; ensure the cord is routed and secured to meet NEC 725 (Class 2 wiring) standards in your jurisdiction. In retrofit jobs, verify the existing 24VAC run has adequate gauge and overcurrent protection at the source.
- Each output is isolated, but all share a common 24VAC rail; do not treat this as a true power-isolated (galvanic isolation) supply for sensitive analog instrumentation. It is designed for switching loads (solenoids, relays, LEDs) not low-level signal conditioning.
- Test PTC reset functionality during commissioning by introducing a deliberate short on one output; confirm power is restored to that channel within 10 seconds and adjacent channels remain unaffected. Document the reset behavior for the customer's operational procedures.
The ALTV248ULCBMI3 is the go-to choice for integrators and facility managers who want granular control over 24VAC auxiliary power distribution without field-wiring eight separate circuits or dealing with fuse replacement uptime losses. For single-device or low-density applications (one or two door locks per zone), a simpler fused supply is sufficient; but for large access-control deployments, mixed loads, or facilities where downtime is costly, the isolation and self-resetting protection justify the investment. See the Altronix catalog for complementary power-distribution and monitoring products.
