Altronix T3MB55PK1 Pre-Wired Access Control Power Distribution Cabinet
Overview
The Altronix T3MB55PK1 is a pre-wired power distribution and access control enclosure built around the T3MB55F16P chassis — a large-format cabinet that consolidates two power supply chargers, eleven reader interface modules, one reader controller, and two power distribution modules into a single deployable unit. At 85.6 lb. and 36.12" x 30.125" x 7.06", this is a purpose-built solution for multi-door commercial and enterprise access control installations where a system integrator needs to minimize field wiring time and reduce the risk of assembly errors on-site. If your project involves deploying eleven reader interfaces from a single location, the T3MB55PK1 ships pre-wired and ready to commission rather than requiring hours of in-cabinet termination.
The enclosure draws 120VAC at 3.5A input and delivers a regulated 12VDC output at up to 10A continuous — enough to power a substantial reader and lock load without supplemental power injection. Battery backup capacity supports batteries up to 40AH or 65AH depending on configuration, giving you meaningful standby runtime for life-safety-critical access points without requiring a separate UPS cabinet.
Key Features
- Pre-Wired Factory Assembly: The T3MB55PK1 arrives with all internal module interconnects completed at the factory. On multi-door projects, eliminating field wiring of eleven reader interface modules can save four to eight hours of labor per cabinet and removes a significant source of termination errors that surface during commissioning.
- Dual Power Supply Chargers: Two onboard power supply charger modules provide both redundancy and load distribution. If one charger degrades, the second can sustain the load, reducing single-point-of-failure risk in installations where downtime has a security consequence.
- 10A / 12VDC Regulated Output: Ten amps at 12VDC is enough headroom for a fully loaded reader and lock configuration across eleven access points when current draw per door is managed within budget. Pair this with your load calculations before specifying — this is not a 24VDC unit.
- Battery Backup to 65AH: The charger circuit supports batteries up to 65AH, which translates to extended standby runtime during a utility outage. For installations governed by NFPA 72 or local AHJ standby-power requirements, the ability to accommodate a 65AH battery in the same enclosure reduces the need for a secondary battery cabinet.
- Instantaneous Failover: Transition from AC mains to battery backup is instantaneous — no brownout gap that could drop readers, unlock doors, or trigger nuisance alarms. This matters on electronic strikes and mag-locks where a power interruption is interpreted as an open signal.
- Supervised Fire Alarm Disconnect: The fire alarm disconnect is supervised, meaning an open or shorted disconnect circuit generates a trouble condition rather than silently failing. This is the correct configuration for life-safety-integrated access control — an unsupervised disconnect is a code violation in most jurisdictions.
- Form 'C' AC Failure and Battery Fault Contacts: Both the AC failure and battery fault conditions provide Form C (SPDT) dry contacts. These contacts integrate directly into panel annunciators, BMS systems, or monitoring stations without additional relay hardware — a practical wiring simplification on large installations.
- Low DC Power Shutdown at 71–73% for 12V: The low DC shutdown threshold prevents deep discharge of the backup battery. Batteries driven below approximately 50% depth of discharge repeatedly have significantly shortened service life; the 71–73% cutoff keeps the battery in a sustainable range and protects the investment in the battery itself.
- Onboard Status LEDs: Dedicated LEDs confirm 120VAC input presence and 12VDC output status at a glance. During commissioning or a service call, technicians can verify power status without a meter, accelerating troubleshooting in a cabinet that may be located above a drop ceiling or in a remote IDF closet.
- 3A/32V Output Fusing: Each output circuit is fused at 3A/32V. Individual fuse protection per circuit means a wiring fault on one reader or lock circuit does not take down the entire output bank — a critical design feature in any multi-door deployment.
- CE Agency Listing: The CE listing confirms the enclosure has been evaluated to relevant European safety and EMC directives, supporting deployments in CE-mark-required markets or in facilities with corporate procurement standards that require agency-listed power equipment.
- Wide Operating Temperature Range: Rated from 0°C to 49°C (32°F to 120°F), the T3MB55PK1 is suitable for installation in unconditioned mechanical rooms, telecom closets without full HVAC, and similar environments that fall outside the 20°C–25°C comfort range of IT closets.
Integration and Compatibility
The T3MB55PK1 is designed as the power and distribution backbone for access control systems using Altronix reader controllers and reader interface modules. The pre-wired configuration is specific to the T3MB55F16P enclosure with the included module complement — verify that your access control head-end is compatible with Altronix reader interface modules before specifying this cabinet. The 12VDC output is not interchangeable with 24VDC system architectures; confirm your reader and lock voltage requirements match before ordering. The Form C dry contacts for AC failure and battery fault are wiring-compatible with most commercial access control panels and BMS annunciators. The supervised fire alarm disconnect must be wired to your fire alarm panel per the AHJ's requirements — confirm the disconnect configuration with your fire alarm contractor during the design phase.
Frequently Asked Questions
Q: What is the maximum battery size the T3MB55PK1 can charge?
A: The onboard charger circuit supports batteries up to 65AH. A 40AH battery is also a supported configuration. Select battery size based on your calculated standby runtime requirement — the charger is sized to handle either without modification.
Q: Does the T3MB55PK1 provide 24VDC output?
A: No. The T3MB55PK1 delivers 12VDC at up to 10A. It is not a dual-voltage unit. If your readers, locks, or controllers require 24VDC, this enclosure is not the correct specification.
Q: How many reader interface modules are included in the pre-wired configuration?
A: Eleven reader interface modules are included and pre-wired from the factory, along with one reader controller and two power distribution modules.
Q: Is the fire alarm disconnect supervised?
A: Yes, the fire alarm disconnect is supervised. An open or fault condition on the disconnect circuit will generate a trouble signal rather than failing silently — the correct configuration for life-safety-integrated access control in most code jurisdictions.
Q: What does instantaneous failover mean for my lock hardware?
A: Instantaneous failover means there is no detectable power gap when the unit transitions from AC mains to battery backup. Electronic strikes and mag-locks that interpret a momentary power loss as an unlock signal will not be triggered by a utility outage or brief power interruption.
Q: What are the cabinet's operating temperature limits?
A: The T3MB55PK1 is rated for operation from 0°C to 49°C (32°F to 120°F), making it suitable for unconditioned mechanical rooms and telecom closets that are not climate-controlled to IT standards.
The T3MB55PK1 is the unit I recommend when a project calls for eleven reader interfaces out of a single cabinet location and the integrator does not want to spend half a day terminating inter-module wiring in the field. The pre-wired configuration isn't a minor convenience — on a cabinet this complex, factory assembly removes a genuine source of commissioning failures. The 10A/12VDC output is adequate for a fully loaded configuration provided you've done your door-by-door current draw calculation; don't assume headroom without running the numbers.
Technical Highlights:
- Dual Charger Redundancy: Two independent power supply charger modules mean a single charger failure does not take the whole cabinet offline. In a life-safety access control installation, that distinction matters more than the cost premium of the second charger.
- 65AH Battery Capacity: Supporting up to 65AH in the same enclosure eliminates a secondary battery cabinet on most projects. Run your standby time calculation against your total door lock current draw — 65AH is substantial headroom for most eight-to-twelve door deployments.
- Supervised Fire Disconnect + Form C Contacts: The supervised disconnect and dual Form C fault contacts (AC failure, battery fault) are what separate a properly designed access control power plant from a compliant-on-paper one. Both feed directly into your panel's annunciator without additional relay hardware.
Deployment Considerations:
- This cabinet is 85.6 lb. unloaded and ships at 106.4 lb. — plan your lift and mounting surface accordingly. The 36.12" x 30.125" x 7.06" footprint requires a dedicated wall section; it won't fit in a standard 19" telecom rack.
- The low DC shutdown kicks in at 71–73% of nominal 12V. This protects the battery from deep discharge, but it also means the cabinet will shut down output before the battery is fully depleted. Factor this into your standby runtime calculations — you will not get 100% of battery nameplate capacity as usable runtime.
The T3MB55PK1 is the right specification for a new construction commercial office build or campus security upgrade where eleven reader interfaces need to originate from a single IDF or security closet and the project schedule does not have room for extended cabinet assembly time in the field.
