Analogue and HD-TVI cameras take their power separately from the video signal, unlike IP cameras which draw power over the same PoE cable as the data. A CCTV power supply here means the box or adapter that feeds that separate 12V DC line to one or more cameras.

Single camera or distribution box?

• Single plug-in PSU — the simplest option for one or two cameras close to the recorder.
• Multi-way distribution box (4, 8 or 16-way) — one mains lead in, individually fused 12V outputs to each camera. The standard choice for a multi-camera HD-TVI system, since it means one power point does the whole job and a fault on one camera does not affect the others.

Size the total output current for every camera on the box, with headroom — see power supplies for the sizing rule that applies across all our PSUs. If a camera has built-in infrared or a heater, check its individual current draw rather than assuming a standard figure.

Wiring and interference

Run 12V power on proper rated cable, not doubled-up data cable, and keep power runs away from mains wiring where possible — a cheap or undersized PSU is one of the most common causes of visible interference lines (hum bars) on an analogue picture.

For IP/PoE cameras, power is supplied by the PoE switch or the recorder itself and no separate PSU is needed — see IP cameras.