The short answer: an FTTH router or ONU draws 6–12 W. On a PE-DU18 that is eight hours or more of runtime, with a transfer time of 10 ms — under one AC cycle — so the PPPoE session and any VPN tunnel survive the gap. The unit sits between the adapter and the CPE, so nothing on the customer side gets reconfigured.
One working day to a written answer · sample from one unit
A router is a low, steady load with one hard requirement: the session must not drop. That moves the design target from “enough energy” to “no interruption at all”. A unit that takes 50 ms forces a re-dial, and on a fibre line that can mean minutes of downtime even though power came back in seconds.
PE-DU18 is the standard build: 18 W output, 100–240 Vac input, USB-C plus 5 V / 9 V / 12 V DC outputs, 10 ms transfer. It installs inline, so the job is unplug-and-replug. PE-DU18-C skips the AC stage entirely where a 12–18 Vdc bus already exists — one conversion less, a few percent more runtime.
Both carry short-circuit, over-current and over-load protection at IP20, and both ship with CE, RoHS and UN38.3 documentation. For ISP rollouts we quote a pilot batch and support a written runtime test on site before the regional order.
The ONU and router stay powered, and the 10 ms transfer is short enough that the PPPoE session normally survives. Whether the ISP's own equipment stays up is outside your control — but a drop at your end is the more common cause.
Yes, if you pick the two-output build: 12 V for the router and 9 V or 5 V for the ONU. Confirm the adapters first — mismatched voltage is the one mistake that kills a CPE.
Under five minutes: unplug the adapter from the CPE, plug the adapter into the UPS, plug the UPS into the CPE. No configuration, no app, no account.
The 18 W output covers most 5G CPE units. High-draw terminals need a larger platform — send the adapter rating and we will say which.
Camera count, adapter rating or cabinet bus voltage is enough to start. You get a model, a runtime figure and the document list for your market.