Ubiquiti INS-3AF-I-G 24V Passive PoE Injector
The Ubiquiti INS-3AF-I-G is a compact PoE voltage converter designed for indoor UniFi and airMAX deployments where standard 802.3af infrastructure must supply power to 24V passive PoE devices. This wall-mount injector bridges the voltage gap between your existing PoE switch or injector and Ubiquiti equipment that expects 24V on non-standard pairs, eliminating per-device external power supplies and simplifying cable runs in distributed indoor networks.
Key Features
- 24V Passive PoE Output: Converts 802.3af or standard Gigabit PoE input to 24V DC passive PoE on pairs 4,5+ and 7,8 return. Supplies 0.5A maximum (12W), suitable for low-power UniFi access points and airMAX base stations.
- Dual Gigabit RJ45 Ports: Input and output connectors support inline deployment between your PoE source and target device. No additional cabling or splitter boxes required.
- ESD & Surge Protection: ±15kV ESD and surge protection on Ethernet pairs guard against transient voltage spikes during installation and hot-swap operations.
- Compact Wall-Mount Form Factor: 30.3 × 95.5 mm dimensions fit tight rack spaces, wall-mounted enclosures, or cable trays. Weight 50g — negligible load on wall anchors or DIN rail.
- Indoor Temperature Rating: 0–70°C operating range targets climate-controlled environments (offices, data closets, equipment rooms). Do not deploy in unheated outdoor cabinets.
- NDAA Compliant: Meets US federal procurement requirements for Department of Defense and civilian agency contracts.
The INS-3AF-I-G solves a common integration problem: you have a Gigabit PoE switch or existing 802.3af injector feeding a network, but your target Ubiquiti device requires 24V passive PoE on non-standard pairs. Rather than recabling the entire switch port or adding a standalone power supply, this injector sits inline and handles voltage conversion transparently. Your switch continues supplying standard PoE, the injector steps it down to 24V passive, and the downstream device receives power in the format it expects.
Power delivery is rated at 0.5A (12W at 24V), which covers entry-level UniFi access points (typically 5–8W during active operation) and airMAX base stations with modest RF output. If you're powering a high-current device (heated outdoor enclosure, multi-radio airMAX node, or a camera with IR), verify the device's actual draw against the 12W budget — exceeding it will trip internal current limiting or create intermittent dropout. Pair this injector with a managed or unmanaged Gigabit PoE source that supplies at least 15W to account for injector overhead and cable loss.
Installation is straightforward: terminate the upstream PoE source to the input RJ45, run a standard Cat5e/Cat6 patch to the target device on the output port, and mount the injector on a wall bracket or DIN rail. The ±15kV ESD protection means you can safely swap cables or devices without powering down — a practical feature in live network environments. Operating temperature 0–70°C is tight for unheated outdoor enclosures or direct-sun mounting, so confirm your installation location stays within range year-round. Ubiquiti recommends this injector for indoor UISP and UniFi deployments where voltage standardization simplifies wiring and reduces per-device power infrastructure.
The INS-3AF-I-G carries Manufacturer Warranty and NDAA compliance, making it acceptable for federal and commercial security system integration where supply-chain provenance matters. It is not a replacement for a full PoE injector or switch — it assumes you already have a PoE source upstream — but as a passive voltage converter it requires no management, no firmware updates, and no power consumption of its own (beyond minimal parasitic draw). For organizations consolidating multiple incompatible PoE voltage standards across indoor UniFi or airMAX nodes, this injector is a cost-effective standardization tool.
Eden PhillipsPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
We've deployed the INS-3AF-I-G across a handful of indoor UniFi and airMAX mixed-voltage environments, and it fills a real gap: when you inherit an existing 802.3af PoE infrastructure but need to add Ubiquiti equipment that expects 24V passive, this injector sidesteps a recabling nightmare. The key differentiator is simplicity — it's passive, requires no external power or configuration, and doesn't introduce management overhead. Where it falls short is power budget: 0.5A (12W) is tight if you're stacking devices or running high-draw RF nodes. On several larger campuses, we've seen teams underestimate device wattage and hit injector current limiting, forcing them to upgrade to a dedicated 24V PoE supply downstream anyway. The real win is in small-to-medium indoor rollouts (10–30 access points) where the per-device power savings justify keeping PoE centralized rather than fragmenting the architecture across multiple supply standards.
Technical Highlights:
- Passive 24V PoE on Non-Standard Pairs: Outputs 24V on pairs 4,5+ and 7,8 return, avoiding the 4-pair overlap of active 802.3at/PoE+. This means your upstream switch doesn't need to support 24V natively — standard 802.3af (48V→24V regulation inside the injector) does the job. Simplifies switch requirements significantly.
- 12W Power Budget (24V @ 0.5A): Adequate for lightweight UniFi 6 access points and small airMAX nodes, but verify device datasheets before deployment. A single high-draw device (e.g., multi-radio outdoor station or heated enclosure) will exceed this budget and require a separate 24V supply or a step-up to a larger Ubiquiti PoE injector.
- ±15kV ESD Protection: Real-world benefit: integrators can swap cables and devices without powering down. On live networks, this translates to fewer maintenance windows and less operational friction. The surge protection also guards against nearby lightning strikes (though it's not a substitute for proper grounding on outdoor-adjacent runs).
- Inline Form Factor (30.3 × 95.5 mm): Compact enough to mount on a wall bracket, inside an equipment rack, or in a cable tray without consuming rack space. Weight is negligible (50g), so standard wall anchors hold it indefinitely. No active cooling needed — passive design means zero thermal load.
- 0–70°C Operating Range: Restricts deployment to climate-controlled indoor spaces. If your installation includes unheated outdoor cabinets, equipment rooms with seasonal swings, or direct-sun exposure, stay below 40°C; above 70°C the device may shut down or degrade output regulation.
Deployment Considerations:
- Verify your target device's power draw before ordering — the 12W budget is firm. A device consuming 15W will either trigger current limiting or operate intermittently. If unsure, contact Ubiquiti TAC with the device model and RF configuration.
- This injector assumes your upstream PoE source (switch, injector, or power brick) supplies at least 15W to account for regulation overhead and cable loss. Underpowered sources (e.g., a 10W injector) will leave insufficient headroom and cause dropout under load.
- Do not cascade multiple INS-3AF-I-G units in series — voltage regulation is designed for a single conversion stage. Stacking them will degrade output stability and may trigger protection circuits.
- RJ45 connectors are standard; use tested Cat5e or Cat6 patch cables. Unterminated or damaged cables introduce intermittent current-limiting events that are frustrating to diagnose — always pull from known-good cable stock.
- The wall-mount bracket is included but minimal — a single screw anchor. In vibration-prone environments (near HVAC ducts, electrical panels), use double-anchor or DIN-rail mounting for stability.
The INS-3AF-I-G is the right tool for small-scale indoor UniFi or airMAX voltage standardization where existing 802.3af infrastructure must coexist with 24V passive devices. It's not a solution for large, power-hungry deployments or outdoor edge cases. For integrators supporting mixed Ubiquiti environments where simplicity and cost matter more than raw power, this injector earns its place in the spares kit. Explore the full Ubiquiti catalog for related PoE infrastructure and access-point options.
