CCTV cable types: how to choose between Cat5e, Cat6, coax and fibre

Cable is the part of a CCTV job that nobody sees and everybody depends on. Camera prices come down and models change every couple of years, but cable often stays in the wall for decades. Choosing it well, and installing it properly, saves you from a kind of fault that is unpleasant to find and expensive to fix.

This guide compares the common types of cable and explains how to choose the right one, plus the traps to avoid.

Quick comparison

Cat5e or Cat6?

For most IP camera installations, either one works. A camera rarely needs more than a few tens of megabits, well below the limits of Cat5e.

Cat5e costs less, is easier to pull and is perfectly adequate for typical cameras at normal distances, when genuine copper is used.

Cat6 generally has thicker conductors, or at least better construction, which helps with heat and voltage drop at high PoE power. It also offers more headroom for future upgrades, and many customers now expect it.

So which one should you use?

• For fresh installs, Cat6 is often a sensible default. The extra cost is small compared with labour, and the cable will likely outlive many generations of cameras.
• For small jobs with short runs and tight budgets, Cat5e is entirely reasonable.
• For high-power devices, such as 802.3bt PTZ cameras, choose better cable and check the manufacturer's guidance.

Whichever you choose, avoid mixing poor-quality connectors, patch leads or joints. A channel only performs as well as its weakest part.

Shielded or unshielded?

Unshielded (UTP) cable suits most sites. Shielded cable (such as F/UTP) may help around strong electrical interference, such as in factories. But shielding has to be correctly terminated and grounded throughout. Done poorly, it can do more harm than good. Use it when the site really needs it, and do the whole channel properly.

The CCA trap

Copper-clad aluminium (CCA) cable looks just like copper, and it's sold cheaply, sometimes labelled as "Cat6". It's not compliant with the usual standards for Ethernet cabling, and it has several weaknesses.

• Higher resistance, which causes greater voltage drop and heat with PoE
• More brittle conductors, which can break when bent or terminated
• More difficult to terminate reliably
• Possible fire-safety problems if it doesn't meet building requirements

Symptoms of CCA include cameras that reboot under load, links that fail at long distances and faults that appear months after installation.

Ways to check:

• Buy from reputable suppliers and ask for solid bare copper specifically.
• Scrape a conductor. Aluminium appears silver beneath a thin copper coating.
• Weigh a box. Genuine copper cable is noticeably heavier.
• Check for a real manufacturer's name and any third-party testing mark on the jacket. Fake markings exist, so don't rely on these alone.

If the price of a box seems too good to be true, it probably is. Saving a little on cable can cost you a return visit that wipes out the job's profit.

Coaxial cable

Coax remains common because of the many existing analog systems, and analog HD systems make good use of it. See our guide on IP vs analog HD.

• Quality matters. Solid copper centre conductors perform far better at distance than copper-clad steel at HD frequencies. Older CCTV cable with copper-clad steel may disappoint when you upgrade.
• Distance depends on the signal type and resolution. Check the maker's figures.
• Connectors matter. Poor BNC crimps are a leading cause of picture problems. Replace old twist-on connectors rather than reuse them.
• Test old cable. Water ingress, kinks and improvised joints may have been hidden at lower resolutions.
• Keep coax away from power cables and be careful with grounding. Ground loops can cause rolling lines and other picture issues.

Siamese cable combines coax with a pair of power wires. It's convenient, but be careful about voltage drop on 12 V supplies. Check the wire gauge and distance, and measure the voltage at the camera under load.

Fibre

Fibre has become much easier to use, and it's the right answer in more situations than many installers assume.

When to choose it

• Runs longer than copper allows
• Links between buildings, where it avoids surge paths and ground differences
• High-capacity backbones between switches
• Areas with heavy electrical interference

Common types

• Single-mode (OS2): Long distances. Now often the preferred choice, as transceivers are affordable and the distance limit is unlikely to be a problem.
• Multi-mode (OM3 or OM4): Shorter distances in buildings. Common in data centres.

Things to plan for

• Fibre needs media converters or switches with SFP ports at both ends.
• Fibre doesn't carry power, so plan for power at the far end.
• Termination requires special tools and skill. You could use pre-terminated cables or a subcontractor until your team is trained.
• Keep the bend radius within limits. Tight bends can cause loss.
• Clean connectors before connecting. Dirt is a very common cause of faults.
• Test with a light source and meter, or an OTDR on long runs.

Ratings: where the cable is going

The same type of cable comes in versions for different environments. Using the wrong one can create safety, durability and compliance problems.

Indoors

• Fire ratings vary by region and building use. Some spaces, such as air-handling plenums in the US or escape routes in many countries, have specific requirements. Check your local rules or ask the customer's consultant.
• Low-smoke zero-halogen cable may be specified for hospitals, tunnels and public buildings, where toxic smoke is a big risk.

Outdoors

Indoor cable jackets degrade in sunlight and moisture.

• Use UV-resistant outdoor-rated cable for exposed runs.
• Use conduit where the cable may be damaged.
• Use water-blocked direct-burial cable, or suitable underground conduit, where cable runs underground.
• Consider armoured or rodent-resistant cable where animals are a problem.

Rodents can cause surprising amounts of damage, especially in ceiling voids and on rural sites. Metal conduit or armoured cable is often worth the extra cost in a known problem area.

Running cable well

Good cable can be ruined during installation.

• Stay within pull limits. Don't drag cable hard through conduit. Use lubricant when needed.
• Avoid tight bends and kinks. Keep to the manufacturer's bend radius.
• Don't crush it. Tight cable ties can deform the jacket. Use hook and loop ties in bundles.
• Separate from mains power. Follow local rules for separation, and cross at right angles when you must.
• Support the cable. Don't rest it on ceiling tiles or tie it to pipes. Follow local rules on supports.
• Leave a service loop. A small loop at the camera and rack makes future changes easier.
• Seal outdoor connections and entries. Use weatherproof boxes, drip loops and proper seals. Water finds every gap.
• Seal fire barriers. Restore fire-rated walls and floors after you pass through them.
• Label both ends. Use a system that's recorded on your drawing.

Testing

A cable that "works" today may not be a good cable. Test and record each run.

• Basic tester: Confirms wire map and continuity. It's the minimum.
• Qualification tester: Confirms whether a link can support a given speed.
• Certifier: Measures against the standard, and might be required by contracts or warranty programmes.
• Real-world checks: Check link speed at the switch, and look for errors on the port.

Keep the results with your job record. They can help you if a dispute comes up later, and they're useful when a fault develops.

Reusing existing cable

Customers often ask whether they can keep existing cable. Test it before committing, and quote with a condition. Old Cat5e may work fine, but check for CCA, damage and poor joints. If reuse fails, you'll need a clear agreement on who pays for the replacement. Our site survey checklist includes this check.

Allowing for cable in your quote

Cable is among the most underestimated items in a CCTV quote. Measure the route, not the straight line. Add allowances for vertical drops, slack and waste. Note the length you've included, and how additional metres will be charged. Our quoting guide covers how to word this.

Decision summary

• New IP installation, under 100 m: Genuine solid copper Cat6, or Cat5e on small jobs.
• Outdoor or between buildings: Outdoor-rated cable, with fibre preferred for links between buildings.
• Over 100 m: Fibre, or a switch placed along the route.
• Existing good coax: Analog HD, or Ethernet over coax adaptors.
• Harsh or interference-heavy site: Proper shielding throughout or fibre.
• Fire-sensitive building: Follow the required rating, and check with the consultant.

Spending a little more on cable is usually one of the cheapest forms of insurance on a CCTV job. The fault you avoid is often the one that would have cost you the most.