Altronix AL642ADA220 NAC Power Extender 24VDC 6A 220V Input
Overview
The Altronix AL642ADA220 is a dedicated Notification Appliance Circuit (NAC) power extender built for fire alarm and security systems that require supplemental current capacity on 220V AC mains. Where a fire panel's onboard NAC output can't drive the full load of strobes, horns, and horn-strobe combos across a large floor plate, the AL642ADA220 steps in — providing a clean, regulated 24VDC output at up to 6A to support those appliance loads without overloading the panel. This is the 220V input variant, making it the correct choice for international installations or domestic facilities wired to 220V branch circuits rather than standard 120V.
Housed in an 18" x 14.5" x 4.5" steel enclosure, the AL642ADA220 is sized to accommodate a standby battery inside the cabinet — a practical design for facilities that need a self-contained, code-compliant solution without dedicating separate rack space to a battery cabinet. If you're specifying Altronix power products for a project, this unit fits naturally into the broader Altronix NAC extender and power supply ecosystem.
Key Features
- 24VDC Output at 6A: Six amps of regulated 24VDC is enough to drive a substantial notification appliance load — strobes, horn-strobes, and bells — on a single supervised circuit without exceeding the panel's rated NAC output. This is the spec that determines how many devices you can hang on the circuit, so size your appliance load against it before specifying.
- 220V AC Input: Accepts 220V mains input, which makes the AL642ADA220 the appropriate model for international projects, embassy installations, manufacturing facilities on 208–240V branch circuits, or any site where 120V is not available at the riser closet. Selecting the wrong input voltage variant is a commissioning failure — this model is specifically engineered for 220V source power.
- Steel Enclosure at 18" x 14.5" x 4.5": The cabinet depth of 4.5" provides enough interior clearance to house sealed lead-acid standby batteries alongside the electronics — reducing field labor by eliminating a separate battery enclosure and keeping the installation footprint compact in electrical or IDF closets where space is at a premium.
- NAC-Specific Design: Unlike a general-purpose power supply adapted for notification duty, this unit is designed from the ground up as a NAC extender — meaning it's built to interface with the panel's NAC output signal and synchronize or relay that signal to the supplemental circuit. This matters for strobe synchronization compliance in facilities subject to ADA and NFPA 72 requirements.
- Supervised Output Architecture: NAC extenders in the Altronix AL642 family are designed to support supervised circuits, which allows the fire panel to detect open or short conditions on the notification circuit downstream. This is a code requirement in most commercial fire alarm installations — a non-supervised extender fails inspection.
Integration and Compatibility
The AL642ADA220 is designed to work in conjunction with a fire alarm control panel (FACP) that provides the NAC trigger signal. It is not a standalone fire panel — it extends the panel's output capacity. Verify panel compatibility before specifying: the panel's NAC output wiring connects to the extender's input terminals, and the extender drives the supplemental appliance circuit from its 24VDC regulated output.
For projects involving fire alarm power supplies and NAC extenders, confirm that the combined appliance load on all circuits — panel-native and extended — stays within the panel's listed capacity. Altronix offers multiple NAC extender configurations; if your project requires 120V input instead of 220V, select the corresponding 120V variant from the same family. If you need higher output current for very large appliance loads, evaluate higher-amperage models in the Altronix line before committing to a configuration.
Battery sizing for the internal battery compartment should be calculated against the standby and alarm current draw of all connected appliances per NFPA 72 annex requirements — typically 24 hours standby plus 5 minutes alarm for most commercial applications. Confirm the physical battery dimensions will fit the 4.5" cabinet depth before ordering batteries separately.
When planning your overall security power supply infrastructure, consider that the AL642ADA220 handles notification appliance circuits only — access control locking hardware, cameras, and other 24VDC loads require separate power supply circuits to maintain proper circuit supervision and load isolation.
Frequently Asked Questions
Q: What input voltage does the AL642ADA220 require?
A: The AL642ADA220 is designed for 220V AC input. It is not compatible with standard 120V branch circuits. If your installation uses 120V mains, select the corresponding 120V input variant from the Altronix NAC extender family.
Q: How many notification appliances can the AL642ADA220 support?
A: The AL642ADA220 provides up to 6A at 24VDC. The number of appliances supported depends on the current draw of each device — divide 6A by the alarm current draw per appliance to determine maximum circuit load. Always leave a safety margin and account for inrush current on strobe devices.
Q: Does the AL642ADA220 include a battery, or is it sold separately?
A: The AL642ADA220 enclosure is sized to accommodate standby batteries inside the cabinet, but batteries are not included and must be specified and ordered separately. Calculate standby and alarm battery capacity per NFPA 72 requirements for your specific appliance load.
Q: Can the AL642ADA220 be used as a standalone power supply without a fire alarm panel?
A: No. The AL642ADA220 is a NAC power extender — it requires a fire alarm control panel to provide the NAC trigger signal. It extends the panel's notification circuit capacity; it does not replace or operate independently of a panel.
Q: What are the enclosure dimensions of the AL642ADA220?
A: The AL642ADA220 enclosure measures 18" x 14.5" x 4.5" (H x W x D). The 4.5" depth is specifically designed to accommodate sealed lead-acid standby batteries inside the cabinet alongside the power electronics.
The AL642ADA220 fills a very specific gap: you have a 220V-fed riser closet, a fire panel whose onboard NAC can't carry the full strobe and horn load for the floor, and you need a listed extender that won't introduce a supervision gap. The 6A at 24VDC output is the number to run your appliance math against before this unit goes on the BOM.
Technical Highlights:
- 6A at 24VDC Output: Six amps is a meaningful ceiling for notification appliance circuits — enough for a large zone of horn-strobes, but you'll hit it quickly on high-candela strobes. Calculate total alarm current draw before committing to a single extender versus a dual-circuit configuration.
- 220V AC Input: This is the distinguishing spec versus the 120V sibling. International projects, embassies, and facilities on 208–240V distribution panels need this variant specifically — installing the 120V version on a 220V branch is a commissioning failure and a safety hazard.
- 18" x 14.5" x 4.5" Enclosure: The 4.5" cabinet depth is engineered to fit sealed lead-acid batteries inside the enclosure — a meaningful labor saver versus running conduit to a separate battery cabinet in a crowded electrical room.
Deployment Considerations:
- Batteries are not included — size your standby battery capacity to NFPA 72 requirements (typically 24-hour standby plus 5-minute alarm) based on the actual alarm current draw of connected appliances, and verify battery dimensions fit the 4.5" cabinet depth before ordering.
- The AL642ADA220 requires a fire alarm control panel NAC output as its trigger signal — it is not a standalone device and cannot activate notification appliances without a panel connection. Confirm panel NAC interface wiring compatibility during design, not on the day of commissioning.
This unit is the right specification for international campus projects, manufacturing facilities on 220V distribution, and embassy or government installations where 220V mains are the standard — anywhere the 120V variant would be the wrong model and the panel's native NAC output can't carry the full appliance zone load.
