Altronix TM400K2D 4A 4-PTC Output Access Control Power Supply for Mercury Panels
Overview
The Altronix TM400K2D is a 115V AC input, 4-amp access control power supply built specifically to support 2–3 door access control deployments running Mercury-based panels. With four PTC-protected outputs, it delivers regulated DC power to locks, readers, and ancillary devices — all on independently resettable circuits that eliminate the single-point failure risk of fused output designs. If you're commissioning a small-to-mid-size Mercury panel installation and need a purpose-matched power distribution solution, the TM400K2D is configured for exactly that scope.
Altronix has been producing access control and surveillance power products for decades, and the TM400K2D sits squarely in their Altronix power solutions lineup targeting integrators who need reliable, field-serviceable power infrastructure rather than field-engineered workarounds. This is a commercial-grade unit sourced factory-new — not grey-market, not parallel import.
Key Features
- 4-Amp Total Output Current: 4A of continuous DC current capacity supports a realistic 2–3 door installation with electromagnetic locks (typically 500–650mA each), card readers, and REX devices running simultaneously — without requiring external supplemental power supplies for a standard Mercury door package.
- 4 PTC-Protected Outputs: Polymeric Positive Temperature Coefficient (PTC) protection on each of the four outputs means an overcurrent event on one circuit — a shorted lock wire, a faulty reader — self-resets once the fault clears. No blown fuses to replace mid-service call, no partial site lockout from a single fuse failure.
- Mercury Panel Compatibility: The TM400K2D is matched to Mercury-based access control systems, the panel platform used by many enterprise-grade access control platforms. Specifying a power supply designed for your panel ecosystem reduces integration risk and simplifies inspection documentation.
- 115V AC Input: Standard North American 115V mains input means no step-down transformer, no custom wiring — plug into any standard commercial electrical circuit. This simplifies rough-in and avoids the added cost of voltage conversion infrastructure.
- 2–3 Door Deployment Scope: The output count and total current budget are sized for a 2–3 door installation. This isn't a limitation — it's a design choice that keeps the unit right-sized, which matters when you're fitting power equipment into compact IDF closets or access control enclosures with constrained footprint.
- Commercial-Grade Construction: Altronix power products are designed for continuous-duty commercial and enterprise environments. This is not a consumer or light commercial product — it's built to run 24/7 in a door control cabinet without maintenance intervention between service cycles.
Integration & Compatibility
The TM400K2D is designed for use with Mercury access control panels and is appropriate for integrations where the Mercury platform is the backbone — including deployments managed through enterprise access control software that uses Mercury as the hardware layer. The four PTC outputs can be mapped to locks, readers, door position switches, or request-to-exit devices depending on your door package configuration.
For larger Mercury installations beyond 3 doors, Altronix offers higher-output variants in the same product family — the TM400K2D is not the right unit if you're powering 4+ door panels or adding supplemental devices that push total current demand above 4A. Plan your current budget before specifying: a typical electromagnetic lock draws 500–650mA, a card reader 150–250mA, and a REX device 50–100mA. Three fully-loaded doors with readers and REX devices lands around 2.4–3A, which keeps you inside the 4A envelope with headroom for inrush.
For a broader view of access control power supplies, including higher-amperage and multi-output options, review the full category to match the unit to your door count and current budget before ordering.
Frequently Asked Questions
Q: How many doors can the TM400K2D support?
A: The TM400K2D is rated and configured for 2–3 door access control installations. It provides 4 PTC-protected outputs and 4A total output current, which covers a typical 2–3 door Mercury panel package including locks, readers, and REX devices.
Q: What does PTC protection mean for field service?
A: PTC (Polymeric Positive Temperature Coefficient) devices are self-resetting overcurrent protectors. Unlike a fuse, a PTC output will automatically reset once the overcurrent condition clears — no fuse replacement required. This reduces service call time and prevents a single wiring fault from taking down the entire power supply.
Q: What is the input voltage requirement for the TM400K2D?
A: The TM400K2D requires 115V AC input — standard North American mains voltage. No step-down transformer or voltage conversion is needed for typical commercial installations in the US and Canada.
Q: Is the TM400K2D compatible with Mercury-based access control systems?
A: Yes. The TM400K2D is specifically matched to Mercury-based access control panel deployments, making it appropriate for integrations using enterprise access control platforms that run on Mercury hardware.
Q: What happens if my current load exceeds 4A?
A: If total connected load exceeds the 4A rating, the unit's overcurrent protection will engage. For installations with higher current demands — more than 3 doors or high-draw locking hardware — you should step up to a higher-amperage Altronix model in the same family rather than overloading this unit.
Q: Can the TM400K2D be used with non-Mercury panels?
A: The TM400K2D is specified for Mercury panel compatibility. While the electrical outputs are standard DC, the product is configured and warranted for Mercury-based deployments. Consult your panel documentation and Altronix application engineering for non-Mercury use cases.
The TM400K2D is a focused piece of kit — 4A, four PTC-protected outputs, wired for Mercury. When I'm speccing power for a 2–3 door Mercury deployment, I want a unit that's sized to the job, not a 10A multi-output supply with half its terminals unused. The TM400K2D is exactly that: purpose-built for small Mercury door packages with a current budget that maps cleanly to realistic door hardware loads.
Technical Highlights:
- 4A Output Current: Enough headroom for three fully-loaded doors — electromagnetic locks at 500–650mA each, readers at 150–250mA, REX devices at 50–100mA — landing around 2.4–3A loaded, which keeps you well inside the 4A ceiling for inrush margin.
- 4 PTC-Protected Outputs: Self-resetting overcurrent protection per output means a shorted field device doesn't require a truck roll just to swap a fuse. The circuit resets after the fault clears — meaningful on a 24/7 commercial door that can't be down while you hunt for a spare fuse.
- 115V AC Input: Standard mains, no voltage conversion hardware. Simplifies rough-in, reduces BOM, and keeps the installation inspection clean.
Deployment Considerations:
- Current-budget your door package before ordering — if you're adding supplemental devices (strikes, maglocks with high inrush, powered REX hardware) beyond a standard 3-door package, tally your steady-state draw plus inrush before committing to the 4A rating.
- The TM400K2D is Mercury-specific in its configuration and application documentation — if your project is migrating to a different panel platform mid-stream, verify compatibility with the new hardware before installing.
This unit is the right call for a corporate office or light commercial Mercury installation covering an entrance, a server room door, and a back-of-house access point — exactly the 2–3 door scope it was designed for. Don't over-specify here; if you're growing past three doors, move up the Altronix family.
