Altronix ACMS8 8-Output Access Power Controller
Overview
The Altronix ACMS8 is a UL-listed sub-assembly designed for integration into wall and rack-mount enclosures. It accepts power from two independent 5–24VDC low-voltage sources and routes that power into eight individually controlled, fuse-protected outputs. Each of the eight outputs can be armed or disarmed independently via trigger inputs from access control systems, card readers, keypads, pushbuttons, PIR sensors, and similar devices. The ACMS8 supports both Fail-Safe and Fail-Secure operation modes, making it suitable for mag locks, electric strikes, magnetic door holders, and other access hardware that requires positive or spring-return behavior during power loss or fire alarm conditions.
Key Features
- Dual Independent Inputs (5–24VDC): Two separate, isolated input paths mean you can supply power from two different power infrastructure sources — or daisy-chain a second controller for system expansion without overloading a single supply line. Each input can accept different voltage (e.g., 12VDC on input 1, 24VDC on input 2), giving you flexibility in mixed-voltage installations.
- Eight Fuse-Protected Outputs (3A/32V per fuse): Individual fuses protect each output circuit, so a short on one door lock won't cascade to adjacent outputs. If a mag lock draws slightly over 3A momentarily, only that fuse blows — the remaining seven outputs keep working. This is critical in multi-door deployments where you cannot afford a single failure to take down the whole system.
- Individually Selectable Fire Alarm Disconnect: You can configure any combination of outputs to drop power when the fire alarm system triggers — or configure all eight to disconnect simultaneously. This is not a global hard-disconnect; it's granular per output, so you can unlock certain doors for egress while keeping others locked based on your facility's emergency evacuation plan.
- Eight Independent Trigger Inputs (NO, NC, Open Collector, Wet 5–24VDC): Each output can be controlled by a different input type. One output might respond to a normally-open (NO) card reader contact, while another responds to a normally-closed (NC) push button, and a third to an open-collector PIR sensor. No need for external relays or converters — the ACMS8 handles mixed trigger logic natively.
- Convertible Outputs to Dry Form "C" Contacts: Outputs can be reconfigured as dry relay contacts, allowing you to switch 24VDC or dry alarm signals to a building management system (BMS) or third-party control panel without the ACMS8 supplying power itself. This extends the controller's utility beyond pure power delivery.
- FACP Interface and Emergency Egress: Direct connection to Fire Alarm Control Panels (FACP) ensures that when the alarm sounds, the access control system responds according to code — unlocking specific doors, dropping power to others, or triggering both simultaneously. Meets egress and life-safety requirements.
- Daisy-Chain Capability via Spade Connectors: Multiple ACMS8 units can be wired in series to expand beyond eight outputs. Useful for large facilities or phased deployments where you add controllers incrementally without replacing the entire infrastructure.
- Low Quiescent Current Draw: Current consumption with all relays energized is only 0.6A @ 12V or 0.3A @ 24V. This low overhead means the bulk of your input budget goes to powering the access hardware (mag locks, strikes), not the controller itself. On a 20A supply, you're left with roughly 19.4A for actual devices.
Integration & Compatibility
Input power must be derived from Altronix eFlow series power supplies (12 or 24VDC). The second input accepts 12 or 24VDC from eFlow supplies, or 5 or 12VDC from an Altronix VR6 Regulator. Maximum total input current is 20A; the main fuse rating is 15/32A. If you exceed 20A peak on both inputs simultaneously, the main fuse will open — this is a hard design limit. For large multi-door installations, plan input capacity carefully: add up all the Fail-Secure strikes and mag locks you intend to power, then confirm your supply can deliver that plus headroom. The ACMS8 is a sub-assembly, meaning it mounts inside an enclosure; it is not a standalone wall-mounted device. Typical installations place it in an Altronix wall-mount or rack cabinet alongside the eFlow power supply.
Deployment Scenarios
Multi-Door Entry Control: A warehouse or office facility with 8 access points (loading dock, staff entrance, secure storage, etc.). Each door has a mag lock and a card reader. Trigger the card reader output on the ACMS8, and power flows to that mag lock for 3 seconds; release, and the lock re-engages. If the fire alarm sounds, all eight outputs drop power, and every door defaults to Fail-Safe (spring-open) behavior for rapid evacuation.
Mixed Fail-Safe and Fail-Secure: A secure data center with a main entry (must stay locked on power loss) and an emergency exit (must unlock immediately on alarm). Configure outputs 1–7 for Fail-Secure mode (powered = locked), and output 8 for Fail-Safe mode (powered = locked, de-powered = spring open). The ACMS8's granular per-output configuration handles this without additional relays.
Phased Expansion: A growing facility starts with four access doors and one ACMS8. As the site expands, add a second ACMS8 via daisy-chaining. No need to replace the original controller or rewire the infrastructure — just plug in the second unit and expand your output count to 16.
Frequently Asked Questions
Q: Can I daisy-chain the ACMS8 to control more than 8 outputs?
A: Yes. Multiple ACMS8 units can be wired in series via spade connectors. Each adds eight more controlled outputs. Maximum daisy-chain length depends on your wiring and voltage drop; consult the datasheet for pin assignments.
Q: What's the difference between Fail-Safe and Fail-Secure mode?
A: Fail-Safe: when power is removed, the door lock springs open (safe for egress, used on emergency exits). Fail-Secure: when power is removed, the door lock remains locked (secure, used on interior high-security doors). The ACMS8 supports both modes — configure each output individually based on your security and life-safety requirements.
Q: Does the ACMS8 work with non-Altronix power supplies?
A: The primary input is designed for Altronix eFlow series supplies (12 or 24VDC). The secondary input can accept 12 or 24VDC from eFlow, or 5 or 12VDC from an Altronix VR6 Regulator. Using non-Altronix supplies may void the UL listing or create voltage compatibility issues. Stick with the specified supply ecosystem.
Q: How much power can each output deliver?
A: Each output is fused at 3A/32V. A typical 12VDC mag lock draws 0.5–1.5A; a 24VDC strike draws 0.3–0.8A. Three high-current mag locks per output would approach the 3A limit. Plan load distribution across your eight outputs to stay within fuse limits.
Q: Can I reconfigure outputs as dry relay contacts for a building management system?
A: Yes. Outputs are convertible to dry form "C" contacts, allowing the ACMS8 to signal status to an external BMS (e.g., "Door 3 is unlocked") without the ACMS8 supplying power. Useful for audit trails and integration with larger facility automation systems.
Q: What happens if the fire alarm triggers?
A: If you've configured fire alarm disconnect on a given output, power to that output drops immediately when the FACP signal activates. This causes any Fail-Safe locks on that output to spring open (emergency egress) and Fail-Secure locks to remain in whatever state they were in at the moment of disconnect. You choose which outputs disconnect and which do not.
Ted PerryPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The Altronix ACMS8 is a workhorse sub-assembly for mid-scale access control deployments. Its dual-input architecture and eight independent, fuse-protected outputs solve a real problem: managing mixed-voltage and mixed-mode access hardware without stacking relays and breakout boards. The ACMS8 ships as a UL-listed sub-assembly, so your enclosure build inherits that listing — important for any facility needing documented compliance.
Technical Highlights:
- 20A Total Input, 3A per Output: With quiescent draw of only 0.3–0.6A, you keep nearly all input budget for actual devices. For an 8-door facility with typical 12VDC 1A mag locks, you're well under capacity. But don't assume you can run eight 2A strikes on one supply — load-balance across both inputs and confirm peak simultaneous draw before commissioning.
- Granular Fire Alarm Disconnect: Most access controllers offer all-or-nothing FACP shutdown. The ACMS8 lets you configure fire alarm disconnect per output. Unlock egress doors, keep secure storage locked — all from one controller, all responding to one FACP signal. This is a compliance plus for large facilities with mixed-security zones.
- Trigger Flexibility (NO, NC, Open Collector, Wet 5–24VDC): You don't need to pre-condition input signals. A card reader's dry contact, a PIR sensor's open-collector output, and a maintained push-button's wet contact can all hit the same ACMS8 without converters. Speeds installation and reduces BOM complexity.
Deployment Considerations:
- Supply Sourcing: Primary input must come from an Altronix eFlow supply. Secondary input can be eFlow or VR6 Regulator. Do not attempt to power the ACMS8 from a generic 24VDC supply — the UL listing is contingent on using specified Altronix power sources. If you're integrating into a facility with non-Altronix infrastructure, plan an eFlow supply addition.
- Voltage Drop and Distance: If your access hardware (mag locks, strikes) is more than 50–100 feet from the ACMS8, voltage drop becomes noticeable, especially on 12VDC. Run heavier gauge wire, or consider powering remote hardware from a second, geographically distributed eFlow supply and daisy-chain a second ACMS8 at the remote location.
- Fuse Replacement and Logistics: Each output carries a 3A/32V fuse. In a busy facility, fuse failures can happen (shorted mag lock, water damage, age). Stock spare fuses on-site, and train facilities staff on safe replacement procedures. A blown fuse takes down one door; preventive inspection saves escalation calls.
The ACMS8 is the right fit for warehouse loading docks, office multi-tenant entries, and secure-storage facilities where you need independent Fail-Safe/Fail-Secure control and fire-code-compliant egress without a software-heavy access control panel. It's a foundation layer for access infrastructure — install it once, reconfigure output behavior through simple wiring changes or card reader programming, and let it run for years with minimal fuss.
