Best PoE Switches for CCTV UK 2026

Sizing a PoE Switch: Ports Are Not the Spec That Matters

Undersize a PoE switch by watts rather than port count and you get intermittent camera drop-outs that look like software faults but are really power starvation once the third or fourth camera comes online. UK installers who size switches by port count alone are the ones fielding callbacks six months later; the ones who size by watts, with headroom, generally aren't. This guide shows you how to do the sums before you buy, using a real switch — the Dahua PFS4218-16ET-240 — as a worked example.

Best PoE Switches for CCTV in the UK 2026: Sizing Your Ports and Power Budget Correctly

The right PoE switch for a CCTV job is the one where port count matches camera count and the total power budget comfortably exceeds every camera's real draw — get either wrong and cameras drop off intermittently, not obviously.

Match ports to cameras, then add headroom. A domestic or small retail install with four cameras suits a 4-port PoE switch with a 65W power budget and extend mode for long cable runs to around 250m — fine for basic bullet or turret cameras but tight if you're running PTZs or cameras with heaters. Larger sites need switches with PoE in the 16- or 24-port range, and this is where the power budget maths actually matters, not just the port count.

Check the per-port and total wattage, not just "PoE and cable calculator". A 16-port switch with a 130W total budget and 30W available per port is enough for IEEE 802.3at (PoE+) cameras but not for 16 cameras drawing near-maximum simultaneously. Step up to a switch such as the Dahua PFS4218-16ET-240, a Layer 2 managed switch built specifically for surveillance with a 240W total budget across 16 × 100Mbps ports and support for Hi-PoE at 250m.

Quick sizing table

What Is a PoE Switch, and Why Does CCTV Need One?

A PoE switch is a network switch that sends both data and electrical power down one Ethernet cable to each camera, removing the need for a mains socket at every camera position. That single feature is what makes network switches with PoE the backbone of almost every modern IP CCTV install rather than an optional extra.

Most IP cameras have no other power path — they draw everything from the switch — so an undersized PoE budget causes real symptoms: cameras rebooting at random, dropping offline overnight, or simply refusing to power up when several are plugged in together. In our experience this is one of the most common fault calls on domestic and small commercial CCTV systems.

The three PoE power classes

Per the HPE PoE switch glossary, a PoE switch combines data and power onto one Ethernet cable rather than requiring separate low-voltage wiring:

• PoE (802.3af) — up to roughly 15.4W delivered per port, enough for most fixed-lens bullet and dome cameras.
• PoE+ (802.3at) — up to roughly 30W per port, needed for PTZ heads, heaters, and IR illuminators that draw more current at start-up.
• Hi-PoE / PoE++ (proprietary or 802.3bt) — 60W or more, used by some multi-sensor turret cameras and ANPR units with onboard heating.

The takeaway: match the switch's per-port and total power budget to what your cameras actually draw, not just the port count.

How Do You Calculate the PoE Power Budget You Actually Need?

Add up the real draw of every camera you plan to connect, then leave at least 20% headroom on top — that total, not the switch's port count, is what actually decides whether a switch is right for the job.

Start with each camera's PoE class from its datasheet. Fixed-lens 2MP and 4MP cameras typically sit within the 802.3af band (up to around 15.4W), while PTZ domes, heated housings and multi-sensor or ANPR units often need 802.3at (up to 30W) or Hi-PoE. Mixing classes on one switch is normal — just total them individually rather than assuming every port draws the same.

Sum the maximum draw, not the typical figure. Cameras spike well above their quoted average when IR LEDs fire at night or a PTZ motor moves, so budgeting on "typical" watts is how installers end up with dropouts on cold, dark evenings.

Add 20% headroom to that total, both to cover cable losses over longer runs and to leave room for one or two extra cameras later without swapping the switch. This headroom figure, not the port count, is the single number that should decide which switch you buy.

Check per-port limits as well as the total. A switch can have a generous overall budget but still cap individual ports too low for a Hi-PoE camera — even with a 230W total budget across 16 ports, a handful of hungry PTZ units need checking against per-port capacity, not just the headline figure.

Port Count and Power Budget: How Do You Avoid Running Out After an Upgrade?

Buy at least one port tier above your current camera count. Running out of ports after an upgrade, alongside underpowering the switch, is one of the common install failures we see on trade orders. A four-camera job that "might grow" is a poor fit for a 4-port switch, because there's no slack for a fifth camera without adding a second switch and another network hop.

Match tier to job size, not just today's camera count. For 1-3 fixed-lens cameras on a small job with no expansion planned, a 4-port PoE switch with a 65W power budget and 250m Extend mode fits — it comfortably covers two or three cameras at roughly 15W each under IEEE 802.3af, but leaves no room for a PTZ or a fifth low-draw camera.

Once a job is at 4-8 cameras, or the client mentions adding cameras next year, step up a full tier rather than filling every port on a small switch. A 16-port unit such as the Dahua 16-Port Managed PoE Switch for CCTV, with its 240W power budget, gives headroom for growth on both ports and watts at once.

Quick sizing table (fixed-lens 802.3af cameras, ~15W typical draw each)

Cameras now	Recommend	Why
1-3, small job, no growth expected	4-port PoE switch, 65W budget, 250m Extend	65W budget suits 2-3 low-draw cameras with headroom; not for PTZ

Unmanaged or Managed: Which Does a CCTV Install Actually Need?

An unmanaged PoE switch is the right default for a single-site CCTV run with a known camera count; step up to managed only when you need VLANs, port-level diagnostics, or remote fault-finding across several switches or sites. For a straightforward four- or eight-camera shop install, managed features add cost and a configuration step that most installers never touch after commissioning.

Unmanaged switches are plug-and-play: connect cameras, connect the uplink, done — there is no web interface to log into.

Managed switches earn their keep once a job outgrows one cabinet. The Dahua 16-Port Managed PoE Switch for CCTV (PFS4218-16ET-240) is a Layer 2 managed switch built for surveillance, offering 16 × 100 Mbps PoE ports, a 240 W total power budget and Hi-PoE support over runs up to 250m. That Layer 2 management gives per-port power monitoring and remote reboot — useful for a retail chain or an installer supporting several sites without a return visit, but unnecessary on a single shop unit.

Brands like Ubiquiti's UniFi range, Netgear and Cisco extend this further with VLAN tagging and centralised dashboards across many switches, which matters when a site has separate camera and office VLANs or when several switches need remote fault-finding from one console. None of that changes the core decision rule.

Related products

Related products from our own range:

• Dahua 16-Port Managed PoE Switch for CCTV — Dahua PFS4218-16ET-240 Layer 2 managed PoE switch for surveillance. 16 × 100Mbps PoE ports, 240W budget, supports Hi-PoE, 250m transmission. Trade supply.