Altronix MAXIMAL3RD 8-Output Access Power Controller
The Altronix MAXIMAL3RD is a 2U rack-mount power controller engineered to distribute regulated 12VDC or 24VDC power to electromagnetic locks, electric strikes, and badge readers across multi-door access control installations. Eight independently supervised outputs deliver configurable current capacity (4A @ 12VDC or 3A @ 24VDC per output) with integrated battery backup and comprehensive system monitoring—AC fail detection, low battery warning, and battery presence supervision. The fire alarm disconnect feature allows emergency systems to de-energize all access points simultaneously, making the MAXIMAL3RD a critical component in life-safety integrated facilities.
Key Features
- Eight Individually Supervised Outputs: Each output monitored independently for load presence and fault conditions. Eliminates single-point failure cascades across multiple doors.
- Dual Voltage Configuration: Selectable 12VDC @ 4A or 24VDC @ 3A per output (6A maximum aggregate @ 12VDC). Matches legacy 12V lock infrastructure or modern 24V ESS systems without hardware swap.
- Battery Backup with AC Fail Detection: Integrated supervised charger holds door locks energized through utility power loss, typically supporting 4-8 hours hold time depending on aggregate load and battery capacity.
- Fire Alarm Disconnect: Hardwired terminal accepts normally-open fire alarm contact. On alarm, all outputs de-energize instantly—forces doors to fail-safe or fail-secure per code requirement.
- Comprehensive Supervision: AC fail, low battery threshold, and battery presence monitoring relay to access control panels and building management systems via supervised output contacts.
- 2U Rack Mount Form Factor: Standard 19-inch rack footprint integrates into data closets, electrical rooms, or dedicated access control racks with minimal real estate impact.
- 115VAC Single-Phase Input: Standard North American utility feed; no three-phase transformer required.
- UL Listed: Third-party certification for fire and life-safety applications; meets AHJ requirements for code-compliant emergency access control.
The MAXIMAL3RD bridges traditional access control power distribution and life-safety integration. In facilities where fire code mandates emergency door unlock on alarm (hospitals, data centers, office buildings), the fire disconnect input ensures legal and safe egress without relying on network communication or backup power to the main access panel. The supervision relays (AC fail, low battery) feed status back to access control software or a separate monitoring system, enabling proactive battery replacement before capacity exhaustion.
Voltage selection (12VDC vs. 24VDC) is a one-time configuration at installation—no jumpers, no field-programmable logic. This simplicity is intentional: access power supply failures in a live facility are emergencies. Hard-wired supervision and fail-safe relay logic eliminate firmware bugs and network latency as failure vectors. For integrators managing 50+ installations, the MAXIMAL3RD's straightforward design reduces truck rolls for misconfiguration and support calls during power events.
Battery sizing and hold time depend on load profile and ambient temperature. A facility with 8 mag locks (typically 0.5A each at 24VDC = 4A aggregate) will exhaust a modest battery in 6–8 hours; adding heating relays or high-current strikes shortens hold time accordingly. Altronix publishes hold-time curves in the datasheet indexed by load and battery capacity—always verify capacity against your door count and lock types before specifying. In installations where 12+ hours hold-time is required, external battery expansion (via Altronix SB battery modules) extends runtime without replacing the power supply.
ONVIF compliance is not applicable to access power supplies; the MAXIMAL3RD integrates via hardwired supervised relay contacts (AC fail, low battery) to any access control panel that accepts dry-contact inputs (Salto, Tyco, HID, DoorKing, etc.). Larger deployments often stripe multiple MAXIMAL3RD units across a rack and feed all supervision relays into a central access panel's alarm inputs, creating a distributed but monitored power topology. UL listing covers both the standalone supply and relay supervision, simplifying AHJ and insurance validation.
The MAXIMAL3RD carries a lifetime warranty on the power supply chassis and transformer; battery warranty is typically 3–5 years depending on purchase date. Replacement batteries and charging modules are field-swappable without removing the supply from the rack, reducing downtime during battery end-of-life replacement cycles.
Jerry TildsenPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
We've installed the Altronix MAXIMAL3RD across everything from small office parks (4–6 doors) to mid-market healthcare and data-center campuses (20+ synchronized supplies). The differentiation versus competitors like Securitron or Pulsar is not feature count—it's reliability under fire code enforcement. The MAXIMAL3RD's fire alarm disconnect is a hardwired input, not software-mediated. That matters when a building inspector is standing in your electrical room asking whether a power failure or network outage could trap occupants. You can point to a relay contact and a datasheet; you're done. Competitors that bake emergency unlock into access panel firmware or cloud logic will fail that conversation. In our experience, the fire disconnect feature drives 30–40% of new MAXIMAL3RD specification decisions—facilities don't shop for backup power supplies, they shop for code-compliant egress assurance.
Technical Highlights:
- Supervised Individual Outputs: Each of the 8 outputs has a dedicated supervision relay contact (normally open) that closes when that output is healthy and powering a load. If a lock shorts or an output fails, that relay opens—the access panel sees the fault instantly. No polling, no network latency. This is especially important in fail-safe installations where lock failure must trigger an alarm immediately rather than waiting for a heartbeat timeout.
- Voltage Flexibility (12VDC vs. 24VDC): You configure voltage once at install based on your lock population. 12VDC is common in older facilities with solenoid locks and buzzer entry systems; 24VDC is standard for modern electronic strikes and RFID readers. The MAXIMAL3RD doesn't require a separate SKU—one part handles both, lowering inventory cost and speeding order-to-install cycles.
- Battery Charger + Supervision Integration: The MAXIMAL3RD includes a dedicated charger for lead-acid or lithium battery modules. The charger also monitors battery voltage and flags low-battery conditions via relay contact before capacity is exhausted. This eliminates the need for a separate battery monitor or UPS—you get one integrated unit.
- Fire Alarm Disconnect (Hardwired): A normally-open contact from your building fire panel connects to the MAXIMAL3RD's fire disconnect input. On fire alarm, the contact closes, and all 8 outputs de-energize within milliseconds. No network, no cloud, no edge controller. Pure relay logic. This is mandatory in any facility with Life Safety Code compliance requirements.
- 2U Rack Density: Eight outputs in a single 2U supply means you can power 8 doors in one compact rack unit. Compare that to a wall-mounted 4-output supply, and you've cut rack real estate by 75%. In facilities with limited electrical room space, density translates directly to cost savings on enclosure hardware and cooling.
- Supervised AC Power Input: The MAXIMAL3RD continuously monitors incoming 115VAC line voltage and flags loss via relay contact (AC Fail). This allows the access panel to log a power event and trigger battery backup behavior before the supply transitions to battery mode—you get visibility into every outage, not just post-mortems from logs.
Deployment Considerations:
- Battery capacity and hold time must be sized at design phase. An 8-door installation with 24VDC mag locks draws roughly 4A sustained; a 7Ah battery provides ~6–8 hours hold time (derate for temperature, age, and charge efficiency). Always calculate aggregate lock current and cross-reference the datasheet hold-time chart before spec. Undersized batteries leave you vulnerable to code violations and emergency unlock failures during extended outages.
- Fire disconnect is a dry-contact input (normally open). Verify that your fire panel's alarm relay can source sufficient voltage and current (typically 24VDC, 50mA minimum). Some older fire panels use low-voltage relay contacts; test the circuit before final commissioning to confirm closure voltage is adequate to trigger the MAXIMAL3RD's input.
- Each output is rated 4A @ 12VDC or 3A @ 24VDC individually. Aggregate maximum is 6A @ 12VDC. Do not assume you can run all 8 outputs at rated current simultaneously—thermal limits and transformer capacity will degrade performance. A rule of thumb: design for 60–70% of aggregate capacity to maintain headroom for peak loads (lock holdover current is often double steady-state on first energize).
- Supervision relay contacts (AC fail, low battery, battery presence, per-output health) are dry contacts—they work with any access control panel that accepts discrete inputs. However, do not wire these contacts directly to a 24VDC supply. These are open-drain relay outputs; they require a panel-side pull-up resistor or supervised loop termination to generate a logic signal. Verify your panel's input specification before field-wiring.
- The MAXIMAL3RD requires a 115VAC outlet within the electrical enclosure (typically provided by the main service or a dedicated sub-panel). In remote installations (rooftop, outdoor kiosk), running a dedicated 115VAC line may require additional conduit, trenching, or generator backfeed design. Budget accordingly—a missed power feed often delays go-live by weeks.
- Battery modules (lead-acid or lithium) are user-replaceable but bulky. Ensure the enclosure door and mounting rails provide sufficient clearance for battery swap-out without disassembling adjacent equipment. On tight rack layouts, a forward-facing battery tray design saves hours of downtime during battery replacement cycles.
The MAXIMAL3RD is the right choice for integrators and end-users building code-compliant, fail-safe access control systems where fire egress is non-negotiable. If your facility requires fire alarm integration, emergency door unlock, and supervised power distribution, this is a proven, UL-listed foundation. For the broader Altronix catalog, the MAXIMAL3RD represents the company's commitment to hardwired, relay-based supervision—a philosophy that prioritizes deterministic safety over feature richness.
