Altronix T3SPK77F24SD 24-Door Siemens SiPass Access Control Power Integration Wall Mount Kit
Overview
The Altronix T3SPK77F24SD is a 24-door access control power integration kit engineered specifically for Altronix/Siemens SiPass deployments. It consolidates access power distribution into a single wall-mount enclosure — delivering 24VDC at 20A from a 115V input, with 24 individually protected door outputs and 8 auxiliary outputs, all in a format that maps directly to SiPass panel architecture. For integrators commissioning large commercial or enterprise access systems, the T3SPK77F24SD removes the need to piece together discrete power supplies across a multi-door footprint and aligns power zoning to the controller's door-by-door structure. Browse the full Altronix access control power line for compatible panels and expanders.
Key Features
- 24-Door Power Capacity: Handles up to 24 doors from a single enclosure — eliminating multiple standalone supplies and the wiring sprawl that comes with them. At scale, that translates directly to fewer service points and a cleaner install in an IDF or head-end room.
- 24VDC @ 20A Power Supply: The 20A output budget at 24VDC provides meaningful headroom across a full 24-door load. Sized to support electromagnetic locks, electric strikes, and request-to-exit hardware simultaneously without operating near the rail's ceiling.
- 24 Fail-Safe / Fail-Secure Outputs (12/24VDC): Each of the 24 door outputs supports both fail-safe and fail-secure locking hardware at selectable 12 or 24VDC — giving you flexibility to mix lock types across a single system without adding conversion hardware or separate supplies for different voltage locks.
- 8 Auxiliary Outputs (12/24VDC, PTC Protected): The 8 PTC-protected auxiliary outputs are purpose-built for readers, door contacts, request-to-exit devices, and other low-current peripherals. PTC (Positive Temperature Coefficient) protection self-resets after a fault clears — avoiding the nuisance service calls that come with blown fuses on high-door-count systems.
- Dual 12VDC Voltage Regulators: Two onboard 12VDC regulators provide clean, regulated voltage for reader-side devices that require stable supply — preventing reader dropouts or erratic credential reads caused by voltage sag under lock-switching loads.
- 115V AC Input: Standard North American 115V mains input means no step-down transformer or special circuit requirement. Drops directly onto a standard commercial electrical circuit — straightforward for the electrician on any new construction or retrofit.
- Wall Mount Form Factor: The wall-mount enclosure format is designed for IDF closets, electrical rooms, and head-end security spaces where rack space is limited or unavailable. Keeps the power distribution co-located with the SiPass panel hardware for short home-run distances to the controller.
- Altronix/Siemens SiPass Integration: Purpose-built for access control deployments running Siemens SiPass — the power architecture maps to SiPass's door-by-door output structure, simplifying commissioning and reducing wiring-to-documentation mismatch during inspection.
Integration & Compatibility
The T3SPK77F24SD is designed as a matched companion to Siemens SiPass access control platforms. The 24-output door power structure aligns to SiPass's panel topology, making it straightforward to assign power zones during system configuration. The selectable 12/24VDC outputs on both door and auxiliary circuits accommodate the range of reader and locking hardware typically specified on SiPass projects — including HID, ASSA ABLOY, and Allegion hardware running at either voltage. Integrators deploying access control power supplies on multi-building or multi-floor SiPass systems can stack or zone T3SPK77F24SD units per riser or floor, maintaining clean power boundaries between access zones. The PTC-protected auxiliary outputs also suit Wiegand and OSDP readers without additional inline protection hardware.
Frequently Asked Questions
Q: What access control platform is the T3SPK77F24SD designed to integrate with?
A: The T3SPK77F24SD is purpose-built for Altronix/Siemens SiPass access control deployments. Its 24-door output structure maps directly to SiPass panel architecture.
Q: What voltage do the door outputs support — 12VDC or 24VDC?
A: The 24 door outputs support selectable 12VDC or 24VDC, allowing you to mix fail-safe and fail-secure locking hardware at different voltages within the same system.
Q: What is the total power output of the T3SPK77F24SD?
A: The unit supplies 24VDC at 20A from a standard 115V AC input, providing a substantial power budget for a full 24-door deployment including locks and reader hardware.
Q: What are the 8 auxiliary outputs used for?
A: The 8 auxiliary outputs (12/24VDC) are PTC-protected and intended for readers, door contacts, request-to-exit devices, and other low-current access peripherals. PTC protection self-resets after a fault, avoiding manual fuse replacement.
Q: How is the T3SPK77F24SD mounted?
A: The T3SPK77F24SD is a wall-mount kit, designed for installation in IDF closets, electrical rooms, or head-end security spaces where the SiPass panel hardware is located.
Q: Why does the T3SPK77F24SD include two voltage regulators?
A: The two onboard 12VDC regulators provide stable, regulated voltage for reader-side devices, preventing credential read errors or dropouts caused by voltage sag when door locks switch under load.
The T3SPK77F24SD is a project-specific unit — it only makes sense if you're running Siemens SiPass, and if you are, it solves a real commissioning headache. The 24VDC @ 20A rail across 24 individually addressed door outputs means you're not trying to load-balance across mismatched supplies or run extended home-runs back to a central rack. The power lives where the doors are.
Technical Highlights:
- 20A at 24VDC: That's enough headroom to run 24 mag-locks simultaneously — most 600lb mags draw 500mA at 12V, which maps to roughly 250mA at 24V each. At 24 doors you're looking at ~6A of door lock draw, leaving significant margin for inrush and reader supply.
- Dual 12VDC Regulators: These matter more than they sound. Regulated 12V rails prevent the reader-level voltage droop that causes sporadic Wiegand misreads on high-door-count systems — a failure mode that's notoriously hard to diagnose after the fact.
- PTC-Protected Auxiliary Outputs: Self-resetting overcurrent protection on all 8 auxiliary outputs means a shorted reader cable doesn't require a truck roll to swap a fuse. In a 24-door enterprise deployment, that's a meaningful operational difference over fused designs.
Deployment Considerations:
- This unit is wall-mount only — verify you have adequate wall space in the IDF or security head-end before spec'ing it. It is not rack-mountable without an adapter, and Altronix does not document one for this SKU.
- The 115V input requires a dedicated circuit in most jurisdictions when paired with a 20A supply — confirm with the electrical sub that a dedicated 20A circuit is in the scope of work before rough-in.
The T3SPK77F24SD is the right call on mid-to-large SiPass projects — corporate campuses, healthcare facilities, or municipal buildings — where the alternative is deploying four to six discrete power supplies and manually zoning them against a 24-door panel. The purpose-built integration shortens commissioning time and gives the SiPass programmer a clean 1:1 power-to-door mapping from day one.
