What wire size is used for CCTV? Most CCTV systems use 18/2 or 18/5 gauge wire for analog cameras under 100 feet. PoE (Power over Ethernet) setups rely on Cat5e/Cat6 cables for power and data. Longer runs require thicker wires (16/2 or 14/2) to prevent voltage drop. Always factor in power requirements, cable type, and distance for optimal performance.
What Are the Main Types of CCTV Cameras?
How Does Voltage Drop Impact CCTV Wire Gauge Selection?
Voltage drop occurs when electrical resistance in wires reduces power reaching cameras. For analog systems, a 5% drop is the maximum allowable threshold. Use thicker gauges like 16/2 for runs over 150 feet. Calculate using Ohm’s Law: Voltage Drop = Current × Resistance. PoE systems mitigate this with higher voltage standards (IEEE 802.3af/at).
Voltage drop calculations become critical when installing infrared cameras or PTZ models with heaters. These devices draw more current during nighttime operation or in cold climates. For example, a 12V camera drawing 1A over 200 feet of 18/2 wire would experience 3.6V drop (30% loss), making 16/2 or 14/2 mandatory. Use this table as a quick reference:
| Wire Gauge | Max Distance (12V) | Max Current |
|---|---|---|
| 18/2 | 100 ft | 1A |
| 16/2 | 200 ft | 1.5A |
| 14/2 | 300 ft | 2A |
What Are the Differences Between Siamese, Coaxial, and Ethernet Cables?
Siamese cables combine power (18/2) and RG59 coaxial for analog cameras. Coaxial cables (RG59/RG6) transmit video but need separate power lines. Ethernet (Cat5e/Cat6) handles PoE, delivering data and power up to 328 feet. Choose based on system type: analog vs. IP cameras and power source compatibility.
Why Does Cable Length Dictate Wire Thickness for CCTV?
Longer cables increase resistance, causing power loss. For analog cameras: 18/2 works up to 100 ft, 16/2 up to 200 ft, and 14/2 beyond 200 ft. PoE systems use Cat6 for 4K IP cameras at maximum distances. Always follow NEC guidelines for outdoor installations and conduit use to prevent signal degradation.
How Does Power over Ethernet (PoE) Simplify CCTV Wiring?
PoE eliminates separate power cables by delivering up to 30W via Ethernet (Cat5e/Cat6). Supports distances up to 328 feet (100 meters) without voltage drop. Ideal for IP cameras, reducing clutter and installation time. Use PoE injectors or switches compliant with IEEE 802.3at standards for high-power devices like PTZ cameras.
Modern PoE standards enable smarter power management. The IEEE 802.3bt (PoE++) specification delivers 90W power, sufficient for cameras with built-in heaters, wipers, or AI processors. When planning PoE installations, consider these power budgets:
| PoE Standard | Max Power | Typical Use |
|---|---|---|
| 802.3af | 15.4W | Basic IP cameras |
| 802.3at | 30W | PTZ cameras |
| 802.3bt | 90W | Thermal/AI cameras |
“Most installers underestimate voltage drop in analog systems. I recommend 14/2 gauge for runs over 200 feet—even if it costs more upfront, it prevents camera reboots during cold weather.”
– James Carter, Lead Technician at SecureVision Pro
FAQ
- Can I use speaker wire for CCTV?
- No—speaker wire lacks shielding, causing interference. Use 18/2 or Siamese cables instead.
- Does Cat6 improve CCTV video quality?
- Cat6 supports higher bandwidth, critical for 4K IP cameras but doesn’t affect analog systems.
- How often should CCTV cables be replaced?
- Inspect every 3-5 years; replace if cracks, corrosion, or signal loss occur.