CCTV Cable 3+1 vs 4+1: Which One Do You Need?
In a CCTV cable, 3+1 and 4+1 describe what is inside the sheath. The “+1” is a single coaxial conductor carrying the video signal. The number in front is how many separate copper cores are bundled alongside it to carry power, and sometimes audio. So a 3+1 is one coax plus three copper cores, and a 4+1 is one coax plus four.
That is the whole distinction, and for most installations 3+1 is the right answer. The situations where the extra core earns its cost are specific, and they are almost always about distance. This guide covers the choice, the coaxial cable underneath it, and what changes on a long run.
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What the numbers mean
An analogue CCTV camera needs two things delivered down one cable: a video signal and a power supply. Those cannot share a conductor, so the cable carries both separately.
The video travels on the coaxial conductor, which is a central copper core inside a dielectric, wrapped in a conductive shield. That shield is the point of coaxial construction. It keeps external electromagnetic noise out of a high-frequency signal, which is why a camera feed can run past fluorescent fittings and motors without turning into snow. The power travels on the plain copper cores, normally as low-voltage DC, with any spare core available for audio or a second supply.
3+1 against 4+1
| Feature | 3+1 | 4+1 |
|---|---|---|
| Construction | 1 coax plus 3 copper cores | 1 coax plus 4 copper cores |
| Power capacity | Standard | Higher, extra core for current or distance |
| Suited to | Fixed cameras, moderate runs | Motorised cameras, long runs, spare or audio core |
| Cost | Lower | Slightly higher |
For a house or a shop with fixed cameras over short to moderate runs, 3+1 is enough and the extra core would sit unused for the life of the installation.
Choose 4+1 when there are motorised pan-tilt-zoom cameras, which draw considerably more current than a fixed unit and draw it in bursts. Choose it on long runs where voltage drop is the concern rather than the signal. And choose it when a spare conductor is worth having, either for audio or because a second camera is likely to appear on that route later. Pulling a cable twice costs far more than the difference between the two constructions.
The coax underneath: RG-59 or RG-6
The other half of the specification is which coaxial type sits inside. RG-59 has a thinner centre conductor and has been the standard for analogue CCTV for decades. RG-6 has a thicker core and lower loss per metre, so the signal survives further.
Coaxial cable attenuates the video signal steadily along its length, and the effect is gradual rather than sudden. A camera that is perfectly sharp at 20 metres can be soft at 100 and unusable at 200, with nothing having failed in between.
| Run length, analogue | What to use |
|---|---|
| Up to around 100 m | Good quality RG-59, bare copper, 3+1 |
| Around 100 to 250 m | RG-6 coax, 4+1, and consider powering locally |
| Beyond around 250 m | UTP with a video balun, or fibre, with local power at the camera |
Why copper-clad aluminium keeps causing trouble
The commonest cause of a disappointing CCTV installation is not the cable type at all. It is the conductor metal.
Copper-clad aluminium, sold as CCA, is an aluminium conductor with a thin copper skin. It looks identical once terminated and it is meaningfully cheaper. It also has substantially higher resistance than bare copper, which costs signal on the coax and voltage on the power cores at the same time. On a short run this is invisible. On a long one it is the whole problem.
Insist on bare copper conductors, and check rather than assume, because CCA is frequently sold without being described as such. Tarang Shakti CCTV cable uses annealed tinned copper throughout.
Long runs, and the problem that is usually power
When a distant camera misbehaves, the instinct is to blame the video path. More often the fault is on the power side.
Thin copper cores lose voltage over distance in exactly the way any conductor does, and a camera that works on the bench at 12 V can be receiving 9 by the time the cable reaches it. The symptoms are misleading: a picture that flickers, a camera that reboots at night when the infrared illuminator switches on and the current draw doubles, or one that works in winter and fails in May.
There are three fixes and they are not equally good. Powering the camera from a local adapter beside it removes the problem entirely and is the right answer on any genuinely long run. Using a 4+1 cable so more copper carries the current helps and is often enough in the middle range. A centralised supply at a higher voltage, designed with the drop calculated in, works but has to be designed rather than guessed.
Two other habits matter on long runs. Avoid joints, because every joint is a reflection point and a resistance in series. And keep the cable away from mains power runs and motor feeds, since the shield is good but not unlimited.
Cable television is a different job
Cable television distribution also uses coaxial cable, but it is not the same product tuned differently. CATV carries much higher frequencies over longer distribution runs, so the priority is low loss per metre and consistent impedance rather than delivering power alongside the signal. Tarang Shakti CATV cable is built for that.
Modern IP cameras change the picture again. They use structured LAN cable and normally take power over the same cable, which removes the separate power cores from the discussion entirely. If the system being planned is IP rather than analogue, the 3+1 against 4+1 question does not arise. The full communication cable range covers both.
Questions people ask
What does the “+1” actually refer to?
The single coaxial conductor carrying video. The number in front counts the plain copper conductors used for power and audio.
Is 4+1 better than 3+1?
Not universally. It adds copper for power capacity, which matters on long runs and with power-hungry cameras. For standard fixed cameras at moderate distance, 3+1 is the correct choice and the cheaper one.
Can 3+1 be used for a PTZ camera?
It can over a short run, but PTZ cameras draw significantly more current, so 4+1 or a local power supply at the camera is the safer specification.
How far can a CCTV cable run?
Good RG-59 handles roughly 100 metres of analogue video. RG-6 stretches further. Beyond about 250 metres, UTP with a balun or fibre is more reliable, and the camera should be powered locally whatever the video path.
Why does a distant camera lose picture at night?
Almost always voltage drop. The infrared illuminator switches on after dark and the current draw rises sharply, pulling the voltage at the camera below what it needs.
