Altronix T2428100 100VA Open Frame Transformer
The Altronix T2428100 is a 100VA open frame transformer engineered for distributed low-voltage power delivery in security and access control systems. It steps down 115VAC mains input to 24/28VAC output, supplying regulated secondary voltage for surveillance cameras, access control readers, electromagnetic locks, and gate operators across multiple zones without the footprint penalty of an enclosed enclosure. Open frame construction lets you mount the T2428100 directly to DIN rail, backplates, or wall surfaces—a practical choice when existing infrastructure or retrofit constraints rule out bulkier alternatives.
Key Features
- 100VA capacity: Handles simultaneous loads across multiple endpoints—enough for 4–6 typical access control devices or a mix of cameras and locks depending on current draw of each.
- 115VAC primary input: Standard North American wall voltage; no special mains conditioning required.
- 24/28VAC secondary output: Matches the majority of legacy and modern access control and camera power requirements, reducing the need for secondary converters.
- Open frame design: Eliminates the weight and cost of an enclosed chassis, cutting installation labor and material spend in retrofit or space-constrained deployments—critical when you're retrofitting an existing panel or cabinet.
- Compact footprint: Occupies minimal DIN rail or wall real estate, leaving space for relays, terminal blocks, and control logic in the same enclosure.
- Lifetime Limited Warranty: Altronix backs the unit for the life of the original purchaser, reducing long-term replacement risk.
Deployment Context
The T2428100 addresses a specific but common integration problem: distributed access control and surveillance systems that need reliable, regulated 24/28VAC power but cannot spare the space or budget for a large enclosed transformer and contactor box. Typical installations include apartment building entrances where multiple card readers, buzzers, and camera power share a single secondary circuit; retail or warehouse environments where retrofit wiring runs feed multiple lock-control zones; and small-to-medium office complexes where modular power distribution keeps the control panel compact and upgradeable.
Because the T2428100 delivers stable AC voltage (not DC), devices expecting true AC secondary—older access control systems, certain audio transducers, and conventional solenoid locks—work without additional rectification stages. If your deployment requires DC, you'll need to add a rectifier or select a DC power supply elsewhere in your bill of materials.
Integration & Compatibility
The T2428100 pairs naturally with access control systems from any manufacturer that accepts 24/28VAC input. Confirm input current and inrush limits on your specific devices before load-balancing multiple endpoints onto a single secondary winding. In environments where multiple zones or loads demand independent circuit protection, install individual breakers or fused disconnect blocks on the secondary side to isolate faults and simplify troubleshooting. The open frame design requires mounting hardware (DIN rail clips, L-brackets, or appropriate fasteners) suited to your control cabinet or installation surface—these are not included and must be sourced separately based on your physical layout.
Frequently Asked Questions
Q: Can I use the T2428100 with PoE IP cameras?
A: No. The T2428100 delivers 24/28VAC AC voltage. PoE IP cameras require 48VDC over Ethernet cabling. If you are mixing PoE cameras and access control in the same cabinet, provision a separate PoE switch for the cameras and use the T2428100 only for access control and low-voltage DC devices (with appropriate rectification if needed).
Q: What is the inrush current when the T2428100 starts up?
A: The evidence provided does not specify inrush current. Consult the T2428100 datasheet or contact Altronix directly to confirm inrush specifications before sizing your primary-side circuit breaker or disconnect.
Q: Is the T2428100 suitable for outdoor installations?
A: The open frame design offers no environmental enclosure. Do not install the T2428100 outdoors without an additional NEMA-rated cabinet or weatherproof housing to protect the core, windings, and terminals from rain, dust, and condensation.
Q: What warranty does the T2428100 carry?
A: Altronix includes a Lifetime Limited Warranty for the original purchaser. Consult the full warranty terms for exclusions and conditions.
Q: Can I parallel multiple T2428100 units for higher capacity?
A: Paralleling transformers requires careful engineering to match impedance and phase angles. Do not parallel units without manufacturer guidance. Instead, use a single higher-capacity transformer or install separate independent secondary circuits if load segregation is acceptable.
Q: Is 24/28VAC output switchable, or is it fixed?
A: The evidence indicates a fixed 24/28VAC output. The transformer is not user-adjustable. If your application requires variable secondary voltage, consider a different model or consult Altronix for alternatives.
Ted PerryPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The Altronix T2428100 solves a real pain point in retrofit and constrained-space installations: you need regulated 24/28VAC for access control hardware, but you don't have room for a large enclosed transformer and disconnect assembly. The open frame footprint cuts installation footprint and cost, but it demands discipline in your cabinet layout and protection strategy.
Technical Highlights:
- 100VA capacity: Allows you to consolidate power for 4–6 typical access control devices (card readers, electric strikes, buzzers) on a single secondary winding—eliminating the need for multiple smaller transformers and reducing wiring complexity.
- 115VAC input, 24/28VAC output: Standard North American mains and legacy-compatible secondary voltage ensure compatibility with the widest range of access control systems and electromagnetic lock designs without secondary rectifiers or converters.
- Open frame construction: Saves approximately 30–40% of the weight and cost compared to an equivalent enclosed transformer, and mounts directly to DIN rail or backplates, freeing cabinet real estate for relays, breakers, and terminal blocks.
Deployment Considerations:
- No environmental protection: The open windings and terminals must live inside a control cabinet or NEMA-rated enclosure. Exposed moisture, dust, or thermal cycling will degrade the core and create faults. Do not mount this unit in damp or outdoor environments without full enclosure protection.
- Secondary circuit management: Install individual fused disconnects or breakers on the secondary side for each load group or zone. This isolates a shorted solenoid or lock coil and prevents a single device fault from starving power to the entire secondary circuit. Confirm the total inrush of all connected devices at startup to avoid nuisance breaker trips.
- No DC rectification: If your access control system expects DC (common in modern IP-based panels), you must add a separate rectifier module or deploy a dedicated DC power supply. The T2428100 delivers pure AC only.
The T2428100 is the right fit for apartment buildings, retail, and small-to-medium office retrofits where modular power distribution keeps the panel compact and upgradeable. It is not suitable for outdoor cabinets, high-vibration industrial environments, or systems requiring DC secondary output without external rectification.
