CCTV Camera Electricity Consumption: Units, Power Supply and UPS Backup

How much electricity does a CCTV camera use?

Each camera usually draws a few watts. Read the camera or adapter label (for example 12 V DC at its rated current); IR night vision adds draw at night. Add the DVR or NVR and its hard disk, then work out units per month = total watts × 24 × 30 ÷ 1000.

Here is a worked example for a 4-camera kit. These are example figures, check your labels; they are not measurements of any product.

One unit on your electricity bill is one kilowatt-hour (kWh). To see what the system adds to your bill, multiply the monthly units by the per-unit rate printed on your own bill.

What draws power in a CCTV system?

The cameras, their night-vision LEDs, any PTZ motors, the DVR or NVR, the hard disk and the PoE switch all draw power. Count each one, because the system runs day and night.

• Cameras: the image sensor and electronics draw steadily all day.
• IR LEDs at night: infrared night vision switches on in the dark, so a camera draws more at night than in daylight.
• PTZ motors: pan-tilt-zoom cameras draw extra when they move and zoom, and usually have a higher rating than fixed cameras.
• DVR or NVR: the recorder encodes and writes video around the clock. Its label or manual gives its rating.
• Hard disk: it spins all the time because recording never stops. Its label lists the current it draws.
• PoE switch: in IP systems it powers the cameras over the network cable. Its wall draw already includes the cameras’ power, so do not count those twice.

How do you read a CCTV camera adapter or PoE label?

Multiply the volts by the amps on the label to get the maximum watts. For PoE cameras, check the PoE class or standard instead. A camera marked 12 V DC, 0.5 A can draw up to 6 W; an adapter marked 12 V DC, 1 A can supply up to 12 W.

• Rated, not average: the label shows the maximum. Daytime draw is usually lower, so using the rating gives you a safe upper estimate.
• Adapter input vs output: the input line (the AC range) is what it accepts from the wall; the output line (for example 12 V DC) is what reaches the camera.
• Polarity and voltage: a replacement adapter must match the voltage, polarity and plug, with an amp rating equal to or higher than the camera’s.
• PoE limits: according to Wikipedia’s Power over Ethernet article, IEEE 802.3af (PoE) supplies up to 15.4 W per port, with 12.95 W available at the device, and 802.3at (PoE+) supplies up to 30 W, with 25.5 W at the device.

A PoE switch also has a total PoE budget. Add up the cameras’ ratings and keep the total below that budget, with headroom for IR at night.

How are analog and IP CCTV systems powered?

Analog HD cameras usually run on 12 V DC from a central SMPS power supply box, with power on a separate pair of wires. IP cameras usually take power through the network cable from a PoE switch or PoE NVR. Our IP vs analog camera guide covers the picture and cost side.

Voltage drop: low-voltage DC loses voltage along a long, thin cable. At night, when IR switches on and current rises, a far camera can reboot, show a dark picture or lose night vision. Use thicker power cores, shorten the run, place a power supply nearer the far cameras, or choose PoE, which runs at a higher voltage and so needs less current for the same power.

How many units per month does a CCTV system use?

Add every item’s watts to get the system total, then use the formula total watts × 24 × 30 ÷ 1000. The table is arithmetic only; multiply the units by your own tariff to get the cost.

Power supplies and PoE switches are not perfectly efficient, so the meter usually reads a little more than the sum of the device ratings. A plug-in energy meter on the CCTV socket gives you the real figure for your system.

How do you keep CCTV recording in a power cut?

Put the DVR or NVR and the camera power supply or PoE switch on a UPS or inverter. Backing up only the recorder leaves the cameras dark. Add the router if you want to watch on your phone during the cut.

1. List everything that must stay on: recorder, SMPS box or PoE switch, and the router for remote viewing.
2. Add their watts to get the backup load, for example 35 W from the worked example above.
3. Find the battery energy in watt-hours: volts × amp-hours. A 12 V, 7 Ah battery holds 84 Wh.
4. Runtime = battery Wh ÷ load W. Here, 84 ÷ 35 gives 2.4 hours at most.
5. Treat that as a ceiling: inverter losses, battery age and the allowed depth of discharge cut real runtime noticeably.

If the CCTV shares a home inverter with fans and lights, the battery drains faster. Some recorders restart when the supply switches over; if yours does, test a UPS on it before relying on it. For the router side, see our guide to WiFi router electricity use and UPS backup.

Does CCTV work without electricity?

No. A mains-powered CCTV system stops recording the moment power goes, unless a UPS, battery or solar supply keeps it running. Footage already saved on the hard disk stays, but the timeline shows a gap for the cut.

• Partial backup: if only some items are on backup, you may get a recorder with no camera feeds, or cameras with nowhere to record.
• Battery cameras: some wire-free cameras run on built-in batteries and record to an SD card or the cloud, usually only when motion is detected.
• Solar plus 4G cameras: for farms, plots and sites with no mains supply, a solar panel charges a battery and the camera sends video over a 4G SIM. The panel and battery must be sized for nights and cloudy days, and the site needs mobile signal.

How do you wire CCTV power safely?

Use a properly earthed socket on a protected circuit, add surge protection and keep the power supply ventilated and dry. Have a qualified electrician handle any mains wiring.

• Earthing: plug the recorder, power supply and PoE switch into an earthed socket, and earth metal enclosures and outdoor poles.
• Surge protection: a surge protector on the CCTV supply, and on long outdoor cable runs, helps guard against spikes from storms and switching.
• Ventilation: keep the recorder and SMPS box in a cool, ventilated spot, away from water and direct sun.
• Outdoor joints: make joints inside weatherproof junction boxes, never with bare tape on an open wall.
• Labels: mark the CCTV socket and breaker so nobody switches it off by mistake.

Our Kasni team offers CCTV installation around Kasni and Jhajjar, with a free site survey and a written quote before any work starts. We fit HD cameras with a DVR, IP cameras with an NVR, and colour night-vision, WiFi, cloud and PTZ cameras, and set up live viewing on your phone. Call or WhatsApp +91-8448523313, Mon–Sat, 9 AM–7 PM.

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