Altronix AL802ULADAJ NAC Power Extender
Overview
The Altronix AL802ULADAJ is a UL-listed voltage-regulated remote notification appliance circuit (NAC) power extender designed to expand fire alarm system capacity without panel modification. It connects directly to any 24-volt or 12-volt Fire Alarm Control Panel (FACP) and delivers stable, regulated 24VDC power to horns, strobes, and visual notification appliances while meeting ADA compliance requirements for synchronized signaling across distributed building zones.
Key Features
- Flexible NAC Configuration: Supports 2 Class A or 4 Class B notification appliance circuits, or 1 Class A and 2 Class B mixed configuration — lets you tailor output topology to your zone layout without rewiring the main panel.
- 8A Total Power Budget with Per-Circuit Limits: Delivers 24VDC at 8A maximum total output, but individual circuits max at 2.5A each — critical constraint when selecting appliances. If you're running eight 1A strobes, you've hit the ceiling; adding a ninth requires a second extender.
- Filtered and Regulated 24VDC Output: Power-limited outputs prevent voltage sag under load, keeping notification appliances at rated brightness and decibel level — especially important in long runs or high-density installations where unregulated supplies drift below 21VDC.
- Dual NC Dry Contact Inputs: Two separate trigger inputs (8–30VDC rated, 6.5mA draw each) allow independent steering of notification circuits to separate zones or building sections from the FACP without additional relay logic.
- Synchronization Support: Compatible with Potter/Amseco, Gentex®, System Sensor®, and CooperWheelock® sync protocols; supports Temporal Code 3, Steady Mode, and circuit follower mode to silence or deactivate horns and strobes simultaneously across multiple floors or wings — mandatory for coordinated evacuation and ADA-compliant alerting.
- Output Loop Supervision with Trouble Memory: Programmable supervised indicating circuit detects open/short faults in NAC wiring; signal circuit trouble memory logs intermittent loop events for diagnostics — reduces time spent tracking down a flaky connection or failed appliance in the field.
- Integrated Ground Fault Detection: Detects ground faults on output loops and provides common trouble input/output for external tie-in — prevents nuisance trips and clarifies whether the fault is in the AL802ULADAJ or downstream in the appliance network.
- Thermal and Short-Circuit Protection with Auto-Reset: Built-in protection cuts power if an appliance shorts, then resets automatically — prevents cascading failures without requiring manual intervention or panel navigation.
- Battery Backup Failover: On AC mains loss, switches instantaneously to battery power (sealed lead acid or gel type, sold separately) — ensures notification circuits remain powered during utility outages or generator switchover delays.
- 120VAC Input, 5A Maximum: Standard single-phase branch-circuit power; draws modest current, so no dedicated 20A circuit required in most deployments.
- Backward Compatible with 12VDC Panels: Works with legacy 12VDC or modern 24VDC FACPs — matters when integrating into older buildings or phased upgrades.
Integration & Compliance
The AL802ULADAJ carries UL listing per UL864 (Control Units and Accessories for Two-Way Fire Systems) and approvals from the NYC Department of Buildings, Factory Mutual (FM), and California State Fire Marshal (CSFM) — necessary for regulated commercial and institutional environments where third-party certification is mandated by code.
Its compact red BC600 enclosure (18" H × 14.5" W × 4.625" D) mounts on wall or DIN rail in electrical closets without consuming excessive rack or floor space. Dual input channels support complex topologies where loop supervision must steer to different zones or buildings depending on activation logic.
When to Choose a Different Model
If your system requires more than 8A total output or supervision of more than two independent zones, consider a higher-capacity extender or multiple AL802ULADAJ units in parallel (each with its own FACP input). If you need integrated battery charging (not just failover), or if your FACP lacks dry contact outputs, a powered control module with built-in charger may be more cost-effective.
Frequently Asked Questions
Q: Can I run multiple AL802ULADAJ units from one FACP?
A: Yes. Each unit accepts dual dry contact trigger inputs, so you can wire multiple extenders to different FACP outputs to distribute NAC load across multiple devices — common in large buildings or multi-tenant facilities.
Q: What happens if an output circuit shorts?
A: The AL802ULADAJ detects the short, cuts power to that output, and auto-resets after the fault clears — preventing a single failed appliance or wiring fault from silencing all horns and strobes.
Q: Does the AL802ULADAJ charge backup batteries?
A: No. It switches to battery power on AC mains loss but does not charge batteries. You must install a separate charger or UPS system to keep sealed lead acid or gel batteries maintained.
Q: What's the maximum wire distance for NAC circuits?
A: Wire length depends on appliance impedance and total circuit current, but 2.5A per output is the hard limit. Long runs increase voltage drop, so verify appliance ratings at end-of-line voltage before commissioning.
Q: Is the AL802ULADAJ compatible with my existing horns and strobes?
A: The AL802ULADAJ works with any 24VDC notification appliance rated for 1A–2.5A. If your appliances require sync signaling (e.g., visual and audible simultaneous activation), confirm they support one of the four compatible protocols: Potter/Amseco, Gentex®, System Sensor®, or CooperWheelock®.
Q: What certifications does the AL802ULADAJ carry?
A: UL864 (fire alarm system control units), FM (Factory Mutual), CSFM (California State Fire Marshal), and NYC Department of Buildings approval — required in most jurisdictions for commercial and institutional fire alarm expansions.
I have specified the Altronix AL802ULADAJ in multi-building fire alarm deployments where main panel NAC capacity falls short of actual appliance load — and it consistently delivers. The 2.5A per-circuit limit is the key constraint to engineer around early, not after install. The AL802ULADAJ handles it, but you must do the math before wiring.
Technical Highlights:
- 8A Total, 2.5A Per Circuit: Gives you breathing room for typical multi-zone expansions (four Class B circuits = four 2A strobes, or mix horns and strobes below 2.5A each) but forces hard decisions in high-density appliance zones — a real-world gotcha that shows up in site surveys.
- Synchronized Notification via Industry Protocols: Potter/Amseco, Gentex®, System Sensor®, and CooperWheelock® support means your horns and strobes silence together on dual input trigger — critical for ADA compliance and tenant experience in multi-occupant buildings where staggered alerts create liability.
- Ground Fault Detection + Trouble Memory: Integrated ground fault detection logs intermittent faults, so you can diagnose a flaky appliance connection or damaged wire insulation without pulling the panel logs — saves hours in the field on troubleshooting calls.
- Auto-Reset Short-Circuit Protection: When an appliance or downstream connection shorts, the AL802ULADAJ cuts that circuit and auto-resets — no manual intervention, no silent evacuation system waiting for a technician to press a button on the main panel.
- Battery Failover (AC Mains Loss): Instantaneous switchover to battery-backed power on utility failure keeps notification active during outages — but remember, this unit does NOT charge batteries, so you must size and maintain external lead acid or gel packs separately.
Deployment Considerations:
- Current Budget Engineering: The 2.5A per-circuit cap is absolute. A single strobe rated 3A will trip protection. Size and test all appliances in a lab or on a bench before field commissioning — saves callbacks.
- Wire Run Voltage Drop: Long NAC runs (150+ feet) to remote appliances incur voltage drop under full load. Verify end-of-line voltage stays above 21VDC to keep strobes at rated candela and horns at rated dB. Use a meter before powering up.
- Sync Protocol Match: Not all 24VDC horns support all four sync protocols. Confirm your appliance model matches one of the supported protocols before spec'ing; mixing incompatible appliances in the same circuit creates field headaches.
- Battery Charger Responsibility: This is a failover device, not a charger. If you're using backup batteries, you must provision a separate UPS or charger module — often overlooked in fast commissioning and a frequent post-install call.
The AL802ULADAJ is the workhorse for NAC expansion in multi-tenant commercial and institutional buildings where the main panel runs out of circuits but you don't need a second control unit. Size your appliance load early, respect the 2.5A per-circuit hard stop, and test sync protocol compatibility — that discipline prevents field rework and keeps notification systems silent only when intended.
