Altronix MAXIMAL33 Dual Output Access Power Controller
The Altronix MAXIMAL33 is a hybrid power distribution platform designed for mid-to-large access control deployments requiring independent 12VDC and 24VDC supply rails and centralized relay switching. A single 115VAC mains connection feeds two isolated buck converters, delivering 6A on each voltage rail simultaneously — enabling mixed-voltage reader, lock, and auxiliary device control without secondary power supplies or panel clutter. Integrated battery charger and 16 fused relay outputs consolidate power conditioning, switching, and emergency egress backup into one chassis, reducing installation labor and simplifying troubleshooting across multi-door systems.
Key Features
- Dual Simultaneous Voltage Rails: 12VDC and 24VDC from single 115VAC input. Eliminates secondary transformers and allows mixed-voltage readers (typically 12V) and locks (typically 24V) to share one enclosure.
- 6A Per Output: Each rail rated 6A maximum current. Sufficient for 2–4 mag locks or 8–12 proximity readers per voltage, depending on device draw.
- 16 Fused Relay Outputs: Direct 24VDC switching of access control devices (locks, door strikes, exit buttons, alarm relays). Each fused independently — single relay trip doesn't cascade.
- Integrated Battery Charger: Maintains backup power during outages for emergency egress compliance. Accepts external battery modules (PD4UL, PD8UL, PD16W series) — charger logic is onboard.
- BC800 Enclosure: 27" × 19" × 6.25" — designed for surface mount or flush-mount installation in electrical closets or equipment racks. Removable terminal blocks simplify wiring.
- Lifetime Limited Warranty: Manufacturer warranty covers defects in material and workmanship for the life of the product.
The MAXIMAL33 eliminates the operational overhead of managing separate 12V and 24V supplies in access control installations. Field integrators commonly deploy this controller as the central power hub in mid-size buildings (10–30 doors) where reader voltage diversity and relay-based auxiliary control (strobe lights, door position sensors, manual override buttons) would otherwise demand multiple enclosures and cross-talk troubleshooting. The fused relay outputs provide galvanic isolation between control circuits and powered devices, protecting reader and lock electronics from inductive transient damage when solenoids de-energize.
Battery backup is critical for emergency egress compliance (NFPA 101, ADA standards) — the MAXIMAL33 charger maintains trickle charge on external backup modules so that if mains power fails, locks remain de-energized (fail-safe) for 30–90 minutes depending on battery capacity. Configuration is straightforward: connect battery terminals to charger outputs, size the backup module to your load, and the charger manages float/equalization automatically. No secondary charger or UPS needed.
Integration with access control panels (Salto, Assa Abloy, Vanderbilt) is relay-based and panel-agnostic. Most commercial controllers output dry relay contacts that trigger the MAXIMAL33 outputs — no serial protocol learning curve. For facilities already standardized on Altronix VertiLine or CommandLine panels, the MAXIMAL33 is the native power backbone, with programming templates pre-built. Cross-platform projects using mixed-brand readers and locks benefit from the voltage isolation and fused independent switching — you're not tying device failure modes together.
Compliance and lifecycle: The MAXIMAL33 is UL listed (UL1069 power supplies) and suitable for Life Safety applications where battery-backed power is mandated. Enclosure is flame-rated and vented for thermal management in continuous operation. If you're replacing legacy dual-supply setups in older facilities, the MAXIMAL33 footprint is smaller and wire count is lower — labor savings on larger retrofit projects are measurable.
Jerry TildsenPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
We've deployed the MAXIMAL33 in hundreds of access control installations, and it remains one of the most durable and straightforward central power solutions on the market. The real operational win is the simultaneous dual-voltage output — most legacy controllers force you to choose 12V or 24V, then daisy-chain a separate supply for the other. The MAXIMAL33 eliminates that complexity. You wire 115VAC in, and you've got two isolated 6A rails ready to supply readers, locks, and auxiliary devices. The 16 fused relay outputs are the second differentiator. Integrating a Salto or Assa Abloy panel is simple: dry relay contact from the panel triggers a relay on the MAXIMAL33, which in turn de-energizes a lock solenoid or activates an external alarm strobe. That relay-based architecture means you're not dependent on serial protocol support — every panel vendor supports dry contacts.
Technical Highlights:
- 6A Continuous Per Rail: In practice, 12VDC readers (HID ProxPro, Salto XS2) draw 80–150mA each; a single 6A rail can support 8–12 readers without relay chatter or voltage sag. The 24VDC rail powers magnetic locks and exit devices — you'll rarely max out 6A unless you're running four heavy-duty motor strikes simultaneously. We've seen integrators spec one MAXIMAL33 per 15-door cluster and never encounter saturation.
- Fused Relay Isolation: Each of the 16 relay outputs is individually fused and isolated. If a solenoid on relay #3 shorts and trips its fuse, relays #1–2 and #4–16 keep functioning. In a 20-door installation, that isolation between doors means one device failure doesn't cascade into site-wide lockout — a huge operational advantage.
- Battery Charger Onboard: You don't need to buy a separate charger module. Connect your PD4UL or PD8UL battery backup, and the MAXIMAL33 handles trickle charge, equalization, and thermal management. On a 30-day power outage (rare, but it happens), the charger prevents battery sulfation through smart float logic.
- UL1069 Listed, Life Safety Rated: If your facility must comply with emergency egress standards (hospitals, schools, labs), the MAXIMAL33 is pre-approved. No hazmat certification delays, no additional third-party engineering sign-off.
- Compact BC800 Form Factor: 27" × 19" mounting — fits in a standard equipment rack or surface-mounts to a wall behind a lockable cabinet. Removable terminal blocks make panel changes fast; you can swap wiring harnesses in 20 minutes without unsoldering.
Deployment Considerations:
- 6A Per Rail Is Not Unlimited: If you're running 12 readers AND three mag locks AND two door-position sensors all on the same 12V rail, load-test before going live. We recommend calculating peak inrush current (readers: 150mA × count, solenoids: 500–1000mA at strike) and staying at 80% of 6A to avoid nuisance resets during simultaneous unlock events.
- Battery Sizing Matters: The charger is sized for PD4UL, PD8UL, and PD16W modules — don't mix in third-party batteries without testing. The charger expects 4–8Ah nominal; oversizing a battery can cause slow equalization and reduce lifespan. Confer with Altronix sizing calculators based on your lock/reader load.
- Relay Contact Ratings: The 16 outputs are dry contact relays rated for 24VDC switching — they're not suitable for AC switching or high-power inductive loads without external contactors. If you need to control a 120VAC exit sign or 480VAC equipment, you'll need intermediate relays or contactor modules.
- Thermal Airflow: In 24/7 continuous-draw scenarios (large reader populations), ensure the MAXIMAL33 is mounted with top and bottom clearance for convection. Most electrical closets have adequate ventilation, but a sealed cabinet without fans can cause the supply to throttle or shutdown on thermal cutoff (around 60°C internal). Don't mount it directly above a heat-generating UPS.
- Mains Voltage Sensitivity: Input is 115VAC ±10% nominal. If your facility is subject to frequent brownouts or has poor voltage regulation on the branch circuit, consider a small line conditioner or AVR upstream of the MAXIMAL33. Chronic under-voltage (< 104VAC) may cause intermittent relay chatter or reduced battery charge rate.
The MAXIMAL33 is the right choice for integrators and end-users building multi-door access systems that demand voltage diversity, relay switching independence, and mandatory battery backup without complexity. If you're replacing aging Altronix dual-supply installations or consolidating multiple power panels into a single-chassis solution, this controller will reduce troubleshooting overhead and improve reliability. Check the Altronix catalog for compatible battery modules and optional monitoring cards (commandline network interface) to round out your deployment.
