Altronix MAXFIT55FD 16-Output 12VDC Access Control Power Distribution Unit

Overview

The Altronix MAXFIT55FD is a centralized 12VDC power distribution unit engineered for multi-door access control and video surveillance installations where clean, fused, fault-isolated power is non-negotiable. Housed in the BC800 enclosure and delivering 9.5A across 16 individually PTC-protected output channels, the MAXFIT55FD consolidates what would otherwise be a tangle of individual power supplies into a single, rack-friendly assembly. If you are commissioning a mid-to-large access control deployment and need a repeatable, inspectable power infrastructure, this is the unit to price into your BOM.

The MAXFIT55FD integrates Altronix ACM8CB access control modules alongside the BC750 power supply chassis — a factory-assembled combination that eliminates field-wiring guesswork between components and delivers a tested, matched stack out of the box. For integrators working under MAXFIT55FD reorder cycles across multiple sites, consistency in form factor and wiring scheme reduces commissioning time meaningfully.

Key Features

• 16 PTC-Protected Output Channels: Each of the 16 outputs is individually protected by a resettable Positive Temperature Coefficient device. A shorted or overloaded run resets automatically when the fault clears — no fuses to chase, no service calls to swap glass. In a 16-door deployment, a single faulted reader or lock does not pull down adjacent doors.
• 9.5A Aggregate Output at 12VDC: At 9.5A total capacity, this unit comfortably supports mixed loads of electric strikes, magnetic locks, and proximity readers. Budget roughly 500mA–1A per door depending on lock type; 9.5A gives you headroom for 8–12 loaded doors without pushing the supply into thermal rollback territory.
• 120VAC / 60Hz Input — Standard Commercial Power: Connects directly to a standard North American commercial circuit. No step-down transformer, no special service required. This matters on retrofit jobs where a dedicated panel circuit is the only available feed.
• BC800 Steel Enclosure: The BC800 provides a lockable, code-compliant housing appropriate for IDF closets, electrical rooms, and head-end equipment spaces. A locked enclosure is a basic physical security requirement on any access control power source — tampered power = open doors.
• Factory-Integrated ACM8CB Modules: The dual ACM8CB access control modules are factory-wired into the chassis, not field-bolted afterthoughts. This means the relay and fused output mapping is consistent across units, simplifying programming documentation and site-to-site standardization.
• Compact Rack Footprint — 19-Inch Width: At 19.00 inches wide, the MAXFIT55FD drops into a standard 19-inch equipment rack without adapters. Depth at 26.00 inches and height at 6.25 inches mean it occupies approximately 3.5U of vertical rack space — verify your rack depth before ordering, as 26-inch depth can be tight in shallow wall-mount enclosures.

Integration & Compatibility

The MAXFIT55FD is designed to pair with Altronix's broader Altronix power and access control ecosystem. The ACM8CB modules provide relay-driven outputs compatible with standard electric strikes, maglocks, and request-to-exit (REX) devices used across the majority of commercial access control platforms. Because the output voltage is a fixed 12VDC, confirm your lock and reader specifications before deployment — some 24VDC-only devices will not operate correctly on this supply. For mixed 12V/24V sites, a separate 24V supply or a dual-voltage Altronix unit may be required alongside this one.

For broader security power supply selection guidance, reviewing your per-door load budget before specifying output count is the single most important pre-design step. The MAXFIT55FD is sized for mid-scale deployments; high-door-count enterprise installations may require multiple units or a higher-amperage chassis from the same family.

Installers integrating this unit into UL-listed access control systems should verify UL listing status for the specific configuration with Altronix directly, as listing scope can vary by assembly combination.

Frequently Asked Questions

Q: What is the output voltage and current of the MAXFIT55FD?

A: The MAXFIT55FD outputs 12VDC at up to 9.5A aggregate across its 16 output channels.

Q: What type of output protection does the MAXFIT55FD use?

A: Each of the 16 outputs uses PTC (Positive Temperature Coefficient) resettable protection. A faulted output resets automatically once the overload or short is cleared — no fuse replacement required.

Q: What enclosure does the MAXFIT55FD ship in?

A: The MAXFIT55FD is housed in the Altronix BC800 steel enclosure, which provides a lockable, code-appropriate housing for equipment rooms and IDF closets.

Q: Will the MAXFIT55FD fit in a standard 19-inch rack?

A: Yes — the unit is 19.00 inches wide and designed for standard rack mounting. However, verify your rack depth before ordering: the unit is 26.00 inches deep, which can exceed the usable depth of shallow wall-mount or compact-footprint racks.

Q: Is the MAXFIT55FD compatible with 24VDC locks and readers?

A: No. The MAXFIT55FD is a fixed 12VDC supply. Devices requiring 24VDC input must use a separate power source. For mixed-voltage sites, plan a complementary 24VDC supply or a dual-voltage Altronix unit.

Q: How many access control doors can the MAXFIT55FD realistically support?

A: With 9.5A at 12VDC and 16 output channels, expect to support 8–12 loaded doors in a typical mixed-lock-and-reader deployment, depending on per-device current draw. Budget 500mA–1A per door as a planning baseline and add up actual nameplate loads before finalizing.

Ted Perry

The MAXFIT55FD is one of those units that earns its place on a project by eliminating four or five individual power supply decisions in one shot. Sixteen PTC-protected outputs at 12VDC and 9.5A total, all in the BC800 enclosure with factory-integrated ACM8CB modules — this is not a parts-list item you assemble in the field; it ships as a matched, pre-wired stack.

Technical Highlights:

• 16 PTC-Protected Outputs: Resettable protection on every channel means a shorted maglocks or a wiring fault on one door does not cascade. On a 16-output unit, fault isolation is not a convenience — it is a code and liability issue on occupied facilities.
• 9.5A at 12VDC: Sufficient aggregate current for 8–12 loaded doors depending on lock type. Maglocks typically run 250–500mA each; strikes run less. Total your nameplate loads before spec-finalizing — 9.5A goes fast on a mag-heavy install.
• 19-Inch Rack Width, 26-Inch Depth: Fits standard open-frame and enclosed 19-inch racks, but the 26-inch depth rules out most shallow-depth wall-mount enclosures. Measure your rack depth before the unit ships.

Deployment Considerations:

• The MAXFIT55FD is strictly 12VDC — any 24VDC readers, locks, or REX devices on the same job need a separate supply. Mixed-voltage sites require explicit power zoning in your design documentation.
• At 39.5 lbs, this is not a solo one-hand install. Plan for two-person mounting, especially in overhead or tight-rack positions where the BC800 enclosure adds handling complexity.

The MAXFIT55FD is best positioned on mid-scale commercial access control retrofits and new construction where 8–16 doors need clean, centralized 12VDC power from a single auditable source — healthcare facilities, commercial office builds, and education campuses with distributed door counts in that range are the natural fit.