Wired security cameras: how PoE systems work

Last updated October 30, 2026

How a PoE camera system fits together

A wired system has three main parts. The cameras, mounted outside or inside. A network cable from each camera, which carries both power and video thanks to power over Ethernet (PoE). And a recorder, called an NVR, that powers the cameras, stores the video on a hard drive, and connects to your internet so you can watch from a phone. Some systems use a separate PoE switch between the cameras and the recorder, which is useful when cameras are far apart or there are more cameras than the recorder has ports.

Why businesses usually choose wired

• Continuous recording. With steady power, cameras can record around the clock instead of only short clips on motion.
• No Wi-Fi dependence. Video travels over the cable, so a weak or jammed wireless signal does not stop recording.
• No batteries. Nothing to recharge on a ladder in January.
• Local control. Video stays on a recorder you own unless you choose to copy it to the cloud.

The trade-offs

Wired systems take more planning and labor. Every camera needs a cable run back to the recorder or switch, through walls, ceilings, attics, crawl spaces or conduit. Outdoor runs need outdoor-rated cable and weatherproof connections. Network cable has a maximum length per run, roughly 100 meters (about 328 feet) for standard Ethernet, so large sites may need a switch partway. And the recorder itself becomes a target: if it sits where an intruder can grab it, the video leaves with them.

Planning the cable runs

1. Mark each camera spot and the area it must cover.
2. Pick a secure, ventilated spot for the recorder, ideally out of sight and near your internet router.
3. Trace the route from each camera to that spot, looking for attic paths, existing chases and places where cable can be protected.
4. Measure each run and add slack for drip loops and future moves.
5. Plan where cables pass through exterior walls and how each hole will be sealed against water and pests.

Storage: how much video can you keep?

How many days of video a recorder holds depends on the number of cameras, resolution, frame rate, compression, and whether cameras record all the time or only on motion. Rather than guess, set the system up, let it run for a few days, and check the oldest footage still on the drive. If it is shorter than you want, add a larger drive, lower the frame rate on overview cameras, or switch quiet cameras to motion recording.

When wireless still makes sense

A wired system is not always the answer. For a rental you will move out of, a detached shed, or one extra spot that would need a long, difficult cable run, a wireless camera can fill the gap. Many of the systems we plan are mostly wired with one or two wireless cameras where cable is impractical.