Altronix MAXFIT11F Supervised Power Supply with Battery Backup
Overview
The Altronix MAXFIT11F is a selectable 12VDC or 24VDC power supply rated at 4A continuous output, housed in a lockable steel enclosure designed for commercial security power supply installations. It ships with dual ACM8 access control modules and a BC750 battery charger, making it a purpose-built distribution point for multi-door access control and surveillance head-end deployments. The MAXFIT11F accepts 120VAC/60Hz input and delivers a regulated DC output with supervised battery backup — a critical combination when you need the system to stay live during a utility outage without relying on a separate UPS.
The enclosure measures 20.5" x 16.5" x 6.25" and weighs 21.2 lbs. unloaded — sized to fit comfortably in an IDF closet or electrical room while still accommodating the included battery. If you're evaluating the broader Altronix power distribution catalog, the MAXFIT series targets mid-size commercial installs where a single, supervised power center replaces a patchwork of individual power adapters.
Key Features
- Selectable 12VDC or 24VDC Output at 4A: A single unit covers both 12V and 24V device ecosystems — wire locks, readers, cameras, and door hardware without stocking two separate supplies. The 4A continuous rating supports four to six mid-draw devices on a single supply without thermal throttling.
- Dual ACM8 Access Control Modules Included: Each ACM8 module adds eight individually fused, supervised outputs. Two modules give you up to 16 individually protected distribution points directly from this enclosure, eliminating external terminal blocks and reducing point-of-failure exposure for multi-reader installations.
- BC750 Battery Charger with 12AH/12VDC Backup Capacity: The included BC750 charges and maintains a 12AH/12VDC sealed lead-acid battery (housed inside the enclosure). During AC failure, the battery sustains output at rated voltage — 12AH at 4A yields roughly three hours of standby, which covers most utility-interrupt windows without a full UPS investment.
- Form C Supervision on AC Failure and Battery: Both AC failure and battery conditions generate Form C dry contacts, making it straightforward to wire supervisory signals to a FACP, alarm panel, or BMS without adding relay modules. If your monitoring system expects a supervised loop rather than a simple voltage signal, the Form C contacts drop directly in.
- Supervised Fire Alarm Disconnect: The fire alarm disconnect input is supervised, not just a passive cut terminal. That distinction matters for UL-listed fire system integrations — an unsupervised disconnect line can mask a cut or open wire and fail inspection.
- Auxiliary Class 2 Output at 1A: A separate Class 2, 1A auxiliary output is available for lower-power ancillary devices (keypads, REX sensors, door position switches) without loading the main 4A bus. Keeping auxiliary loads separated also simplifies troubleshooting — a faulty sensor won't pull down the primary distribution rail.
- Input Fuse at 5A/250V, Battery Fuse at 7.5A/32V: Dual fusing protects both the AC input and the battery circuit independently. The 7.5A battery fuse on a 12AH cell is correctly sized to limit inrush on deep discharge recovery without nuisance trips during normal float charging.
- Operating Range 0°C to 49°C with 85% ±5% RH Rating: The temperature range covers typical indoor equipment room conditions including unconditioned telecom closets that can run warm in summer. The 85% RH ceiling means the unit handles humid mechanical rooms but isn't rated for outdoor or wash-down environments — plan accordingly.
Integration and Compatibility
The MAXFIT11F is built around Altronix's ACM8 output modules, which are widely paired with access control panels from major commercial access control systems including those requiring individually fused, supervised lock power outputs. The Form C supervisory contacts wire directly to panels that monitor auxiliary input zones. The fire alarm disconnect integrates with FACP auxiliary relay outputs wired to cut power on alarm — a standard requirement in life-safety-integrated access control designs.
For camera and recorder infrastructure co-located in the same enclosure room, this supply can feed PoE injectors or low-voltage cameras if you keep total draw within the 4A output. It is not a PoE switch — cameras requiring 802.3af/at over Ethernet need a separate PoE switch or injector downstream. The selectable 12V/24V output also pairs with most electrified hardware (magnetic locks, electric strikes, electric latch retraction) common to commercial electric lock installations, provided the device draw falls within budget per ACM8 output.
Frequently Asked Questions
Q: What battery size does the MAXFIT11F support, and is it included?
A: The MAXFIT11F is designed for a 12AH/12VDC sealed lead-acid battery. The BC750 charger is included in the unit, but verify with your supplier whether the battery itself ships with the enclosure — battery inclusion varies by configuration and distributor packaging.
Q: Can the MAXFIT11F output be switched between 12VDC and 24VDC in the field?
A: Yes. The output voltage is selectable between 12VDC and 24VDC. Select your voltage before wiring loads — do not switch voltage with devices connected, as this can damage 12V-rated hardware if switched to 24V under load.
Q: What does the supervised fire alarm disconnect do?
A: The supervised fire alarm disconnect allows a fire alarm control panel to cut power to connected locking hardware on alarm activation — a code requirement in most life-safety-integrated access control designs. The supervision on this input means an open or shorted wire to the disconnect terminal will be detected, which is required for UL-listed fire integration in many jurisdictions.
Q: How many fused outputs does the MAXFIT11F provide?
A: With two ACM8 modules included, you get up to 16 individually fused distribution outputs. Each ACM8 provides 8 outputs, allowing per-device fusing that isolates a fault to a single circuit rather than taking down the entire supply.
Q: Is the MAXFIT11F suitable for outdoor installation?
A: No. The MAXFIT11F is rated for indoor use with an operating temperature range of 0°C to 49°C and up to 85% relative humidity. It is not weatherized or rated for outdoor mounting. Install it in a conditioned or semi-conditioned indoor space.
Q: What are the enclosure dimensions and weight?
A: The enclosure measures 20.5" x 16.5" x 6.25" and weighs 21.2 lbs. without battery. Shipping weight is 26.6 lbs. Plan wall anchor points accordingly — at this weight with a battery installed, use appropriate toggle bolts or wood-stud anchoring.
The MAXFIT11F is the unit I reach for when a project needs a single, supervised power center for a multi-door access control head-end and the design doesn't allow for a patchwork of individual wall-wart supplies. The 12AH battery capacity paired with the BC750 charger gives you a genuine standby window — at a 4A continuous draw you're looking at roughly three hours of battery runtime, which covers most utility interrupts without the cost and complexity of a full UPS cabinet.
Technical Highlights:
- Dual ACM8 Modules (16 Fused Outputs): Two ACM8 modules deliver up to 16 independently fused outputs directly from this enclosure — per-circuit fusing means a shorted strike or faulty reader takes down one output, not the entire distribution rail.
- Form C Supervision on AC and Battery: Both supervisory contacts are Form C dry contacts, which wire directly into most alarm panels and BMS zone inputs without relay modules — this eliminates an entire layer of external hardware that can fail.
- Supervised Fire Alarm Disconnect: The supervised disconnect input — not a passive cut terminal — is the detail that keeps this unit compliant in life-safety integrated designs. An unsupervised line can mask a wire cut and fail inspection; supervision closes that gap.
Deployment Considerations:
- At 21.2 lbs. unloaded and 26.6 lbs. shipping weight, wall anchoring requires proper stud or toggle bolt planning — a battery-loaded enclosure at this mass needs more than drywall anchors, especially in high-vibration mechanical rooms.
- The 0°C to 49°C operating range covers most indoor equipment rooms, but unconditioned utility closets in hot climates can exceed 49°C in summer — verify ambient temperature before mounting, or add supplemental ventilation.
The MAXFIT11F is a strong fit for commercial office or education campuses with three to eight controlled doors per IDF, where the combination of supervised battery backup, Form C alarm contacts, and fire disconnect in a single lockable enclosure satisfies both the security integrator and the AHJ in a single riser-room installation.
