2026-09-29

How to Select a CCTV Power Supply

Power SupplyCCTVSecurity

A CCTV power supply is sized from the sum of every camera's current draw — including the IR LEDs that surge at night — plus margin for inrush and future cameras. Centralised boxes, individual adapters and PoE each have a place.

The Short Answer

Add up each camera's amps at 12V (day + IR-night load), total them, multiply by 1.3 for headroom, and pick a 12V supply rated for that. For a few cameras, individual regulated adapters are simplest; for many, a centralised CCTV box (or PoE) is cleaner.

Step 1: Add Up Camera Current

A typical 12V bullet / dome camera draws ~0.5A by day and ~0.8–1A with IR on at night. Always size for the night (IR) load, the worst case. 8 cameras × 1A = 8A.

Step 2: Add Headroom

Inrush: cameras and IR draw a surge at switch-on.
Future expansion: leave 1–2 spare channels.
Rule: PSU amps ≥ total × 1.3. 8A × 1.3 ≈ 10.4A → choose a 12V 12A (144W) box.

Step 3: Choose the Topology

Individual adapters — best for 1–4 cameras; isolated faults, cheap. See router / CPE adapter guide for the same logic.
Centralised CCTV box — one 12V multi-amp supply feeding all cameras via fused outputs; tidy for 4–16 cameras, but one failure kills all (use a quality unit).
PoE (802.3af / at) — data + power over one CAT5e / 6; safest for new installs, limited to ~30W per camera.
DIN-rail PSU — for panel-mounted, industrial CCTV. See the DIN rail guide.

Step 4: Cable & Voltage Drop

Long 12V runs sag. Use thicker cable for distance, or step up to 24V distribution with local 12V regulators. Keep end-of-cable voltage within the camera's 12V ±10%.

Outdoor & Enclosures

Use IP-rated enclosures and a supply rated for the ambient range. XGW enclosed and CCTV-grade PSUs cover 12V / 24V surveillance. Browse Power Supplies or request a quote for project sizing.

FAQ

12V or 24V for CCTV?

For short runs 12V is fine; for long cable runs step up to 24V distribution with local regulation to beat voltage drop.

Is PoE better than a 12V box?

For new installs PoE simplifies wiring and isolates faults per port; for retrofits a centralised 12V box is often cheaper.