CCTV is almost always installed in a house or office where mains wiring is either already in place or being run at the same time. Camera cable is a low-voltage, signal-carrying line, and running it too close to power cables doesn't go unnoticed — footage gets stripes, flicker, and in some cases a camera stops working reliably at all.
Here's what cable to use, how far to keep it from mains wiring, and how to plan the route so you don't have to redo channeling after the cameras are already mounted.
What cable CCTV actually needs
For IP cameras — now the standard choice for new systems — installers typically use category 5e or 6 UTP twisted-pair cable, which carries both the video signal and camera power over PoE (Power over Ethernet), if the recorder or switch supports it. That's convenient: no separate power cable is needed to each camera.
For analog cameras, a coaxial cable carries the signal plus a separate two-core 12V cable handles power. That setup is cheaper on hardware but means running two lines to every camera point instead of one.
Why camera cable shouldn't run next to mains wiring
Mains wiring, especially circuits carrying heavy loads — an oven, a washing machine, a pump — generates an electromagnetic field around the cable. A low-voltage CCTV cable running parallel and close to it picks that field up as interference: the image shows noise or stripes, and on longer runs the signal can degrade enough to drop the camera's connection entirely.
There's also a mechanical risk: if camera cable is accidentally routed in the same conduit or duct as a mains cable and the mains cable's insulation gets damaged, the low-voltage line and the equipment connected to it can end up carrying dangerous voltage.
Minimum distance and how to separate the two runs
Good practice is keeping low-voltage cable at least 30 cm from mains lines when running them in parallel, whether open or in a shared duct with a partition. Where the two runs do have to cross, cross them at a right angle — that minimizes interference.
- Where possible, route mains and low-voltage cable in separate channels or separate ducts.
- If a shared duct is unavoidable, use one with a partition between compartments.
- Shielded cable (F/UTP, SF/UTP) reduces sensitivity to interference when physical separation isn't possible.
- Never bundle low-voltage cable together with mains cable — even temporarily during installation.
Powering cameras: separate line, PoE, or backup
If the system is built on PoE, cameras don't need a separate power line at all — power travels over the same UTP cable from the switch or a PoE injector at the recorder. That simplifies both cable runs and channeling: only one thin cable needs to reach each camera.
If cameras are analog, or the hardware doesn't support PoE, cameras need a separate 12V line from a power supply, ideally wired to its own circuit in the panel with an appropriately rated breaker — that way a fault in the CCTV circuit doesn't affect the rest of the house wiring. For genuinely critical setups, it's worth powering the recorder and camera power supply through a UPS so the system keeps recording through short outages.
Planning the route from panel to cameras
It helps to plan the CCTV route the same way you'd plan mains wiring: mark camera positions and the recorder location first, then route the cable the shortest way while routing around mains lines. If channeling for electrical work is already happening in the house or office, it makes sense to run the CCTV route at the same time — separate low-voltage channels add very little extra work, while redoing finished walls for a new run later costs noticeably more.
Outdoors, camera cable should run inside conduit or a weatherproof duct, with some slack left in case a camera needs repositioning later.
Common mistakes in CCTV installation
- Camera cable and mains cable sharing one conduit with no separation — this almost guarantees image interference.
- Using non-standard cable (like plain two-core wire instead of twisted pair) on runs longer than 20-30 m — the signal degrades.
- No slack left at the camera or recorder — repositioning even slightly means pulling a whole new line.
- Powering cameras straight from a household outlet with no dedicated breaker — a short in the camera circuit can trip an entire lighting or outlet group.
If CCTV is being planned alongside electrical work in a house or office, it's worth designing both routes together — that's easier to plan once than to channel the walls twice.