Home Security Camera and Alarm Wiring: Planning, Running Cable, and Power

Wired vs. Wireless Cameras

Wired PoE (Power over Ethernet) cameras get both power and data through a single Cat6 cable. No separate power supply needed at each camera. Reliable, consistent connection. No batteries to charge. Image quality up to 4K without compression artifacts from Wi-Fi.

Wireless Wi-Fi cameras are easier to install (mount, plug in or charge battery, connect via app). But they depend on Wi-Fi signal strength, which drops through walls and distance. Battery cameras need recharging every 1-6 months. Most require a cloud subscription for recording, which adds up over years.

Hybrid approach: use wired cameras for permanent, critical locations (front door, driveway, back yard) and wireless cameras for temporary or flexible placement (baby monitor, garage workshop, rental property).

Planning Camera Locations

Cover entry points first: front door, back door, garage door, and ground-floor windows are where 95% of break-ins occur.

Mount cameras at 8-10 feet height, angled downward. High enough that they cannot be reached and knocked down, low enough to capture faces rather than the tops of heads.

Consider the field of view. A camera covering the front door should also capture the walkway or porch where a person approaches. A driveway camera should capture the full width of the driveway plus the area where someone would walk to the house.

Lighting matters. Infrared night vision on most cameras reaches 30-100 feet. For areas beyond that range, add motion-activated lighting. Cameras perform best when not pointed directly at a light source — mount them beside lights, not under them.

Running Cable

Plan the cable route from each camera location to the NVR (network video recorder) or PoE switch location. The NVR typically lives in a closet, basement, or utility room near the router.

Cat6 Ethernet cable: maximum run length of 328 feet (100 meters) for PoE. Use outdoor-rated cable for any exterior runs. For runs through attics and walls, standard riser-rated (CMR) cable is fine.

Drill through the exterior wall from inside at each camera location. Angle the hole slightly downward on the outside so water does not follow the cable in. Seal around the cable with silicone caulk after running it.

Route cable through the attic, wall cavities, or basement to the central location. Use cable clips or J-hooks to support runs in the attic — do not lay cable on top of insulation where it can be displaced or damaged.

Terminate each cable with an RJ45 connector or a keystone jack in a wall plate. A crimping tool and Cat6 connectors are straightforward to use with practice. Alternatively, buy pre-terminated cables in the right lengths and fish them through the walls.

NVR and PoE Switch Setup

An NVR with built-in PoE switch is the simplest setup — plug the camera cables directly into the NVR ports. The NVR provides power to the cameras and records the video to an internal hard drive.

For more cameras or more flexibility, use a separate PoE switch connected to the NVR via Ethernet. This lets you place cameras on the same network as the NVR without running every cable to the same location.

Storage: calculate based on camera count and quality. At 4K, one camera recording continuously uses about 1TB per 7-10 days. Motion-activated recording uses 70-80% less storage. A 4TB drive handles 4 cameras with motion recording for about a month.

Place the NVR in a secure, ventilated location. It should be accessible for maintenance but not obvious to an intruder. A locked closet or basement cabinet is ideal. Connect the NVR to your router for remote viewing via the manufacturer's app.

Basic Alarm Sensor Wiring

Traditional wired alarm systems use thin 22-gauge 4-conductor wire running from each sensor (door/window contacts, motion detectors) back to the alarm panel. Modern wireless alarm systems (SimpliSafe, Ring Alarm) have largely replaced wired for DIY installation.

If you are wiring sensors during new construction or a renovation, run the wire while the walls are open. Door and window contacts mount inside the door/window frame with the magnet on the moving part and the switch on the fixed frame.

Motion detectors mount in room corners, 6-8 feet high, aimed diagonally across the room. Avoid aiming at windows (sunlight can trigger false alarms) or at heat sources (HVAC vents, fireplaces).

All sensor wires terminate at the alarm panel. The panel monitors each circuit — when a contact opens (door or window opens) or a motion detector triggers, the panel reports the zone and activates the alarm.

Tools for Security System Wiring

Cable: Cat6 for cameras (outdoor-rated for exterior runs), 22/4 for alarm sensors. RJ45 crimping tool and connectors for Ethernet. Fish tape, glow rods, and a flex bit for routing cable through finished walls. Drill with long masonry bit for exterior wall penetrations.

For mounting cameras: drill/driver, masonry anchors for brick or concrete, stainless steel screws for wood. Silicone caulk for sealing penetrations. Cable clips or J-hooks for supporting runs.

A cable tester ($20-30) verifies each Ethernet run before connecting to the NVR. Finding a bad crimp or a cable break after everything is mounted and sealed is much harder than testing first.

Frequently Asked Questions