The 100 m limit in the Ethernet standard is a data limit, set by signal loss. Power over Ethernet adds a second limit that depends on the cable: how much of the switch’s voltage is left at the camera after 90 m of conductor.
What the standard assumes
IEEE 802.3af (15.4 W) and 802.3at (30 W) are designed around a 100 m channel on 24 AWG copper with a loop resistance of 25 Ω or less. Thinner conductors, aluminium conductors or a poor termination push the loop resistance up, the voltage at the camera falls, and the camera either fails to boot or reboots when the IR LEDs or the heater switch on.
Why 23 AWG helps
WIAN Neo and Gold Series CAT6A cables use 23 AWG solid copper with a datasheet conductor resistance of 93.8 Ω/km maximum. On a 90 m run that is about 8.4 Ω per conductor, or 16.9 Ω loop resistance on one pair — and PoE uses two pairs in parallel, which halves it again. A 24 AWG copper cable runs about a quarter higher; CCA roughly half as much again. The thicker copper conductor is the single biggest reason a far camera powers up reliably.
Heat in the bundle
PoE+ and the newer 60 W and 90 W standards warm the cable. Bundled cables in a hot riser or a sunny tray can exceed their operating temperature, which raises resistance and loss further. Our cables are rated to +75 °C in operation; keep bundles to 24 cables or fewer where high-power PoE is in use, and use the outdoor LDPE jacket (WC-2268K, WC-2264K) where the tray is in the sun.
The checklist for a far camera
Solid copper, 23 AWG. One continuous run — no couplers in the middle. Patch cords at both ends of the same category. A PoE tester at the camera end before the camera goes up: you want to see the voltage and the negotiated class, not just a link light. Beyond 100 m, a PoE extender or an outdoor PoE switch at a mid-point box, each leg under 90 m.
A 90 m camera on CAT6A pure copper is routine. The same camera on 24 AWG CCA is a call-back waiting for the first cold night.