If you're installing IP cameras, a PoE switch is a key infrastructure element — it powers the cameras and provides data connectivity over a single cable. The right choice saves money and avoids dropouts.
What is PoE
Power over Ethernet (PoE) delivers power on the same UTP cable as data. No separate power cable and supply at each camera — just one cable from the switch. Range is up to 100 m on Cat5e/Cat6 cable.
PoE standards — 802.3af vs 802.3at vs 802.3bt
- IEEE 802.3af (PoE) — up to 15.4 W per port (12.95 W actually after cable losses). Suitable for most IP cameras without long-range IR and without motorzoom.
- IEEE 802.3at (PoE+) — up to 30 W per port (25.5 W actually). Required for cameras with powerful IR (>50 m), motorzoom, heating (outdoor in frost) or PTZ cameras.
- IEEE 802.3bt (PoE++) — up to 60 or 90 W. For specific applications (high-power PTZ, 4K PTZ, multi-sensor cameras). Overkill for normal installations.
Rule: If you have standard bullet/dome cameras up to 5 MP and without heaters → 802.3af is enough. For outdoor in frost, PTZ or cameras with long IR → 802.3at.
Power budget — the most common mistake
The switch spec lists the total power (budget) and max power per port. Don't mix these up!
Example: a switch with 8 PoE ports, each 30 W (802.3at), budget 120 W. That means 8 × 30 W = 240 W WILL NOT work. Realistically you can power about 4 cameras at full power, or 8 cameras at half consumption.
Rule: Add up the actual camera consumption (in the datasheet) + 20% buffer. That must be less than the switch's PoE budget.
Number of ports — cameras + buffer
Recommended port counts by camera count:
- 1–3 cameras — 4-port switch
- 4–6 cameras — 8-port switch
- 7–12 cameras — 16-port switch
- 13+ cameras — 24-port or 2× smaller in cascade
Always have at least 1 spare port for the upstream link to the NVR or router.
Upstream port — link to the NVR
The PoE switch must be connected to the NVR or router via a non-PoE gigabit port. The so-called uplink port is usually marked.
Variants:
- NVR has its own PoE switch (e.g. PATRONUM PRNVR16P) — internal switch powers cameras directly, no external switch needed
- External PoE switch + NVR without PoE — connect the uplink to the NVR's LAN port
- Two switches in cascade — only the main switch links to the NVR, the second is connected as a sub-ring
Gigabit (1 Gb/s) or 100 Mb/s?
For 1–4 cameras up to 4 MP a 100 Mb/s switch is enough. For more cameras, 4K resolution or NVR LAN output always pick gigabit. The price difference is minimal.
Managed vs unmanaged
- Unmanaged — plug and play. Recommended for normal residential installations.
- Managed (L2+) — supports VLAN, QoS, SNMP monitoring. Suitable for businesses and large projects where you want to isolate cameras from the rest of the network.
For a residential project a managed switch is unnecessarily expensive and complex.
Recommendations by project
- 4 cameras / family house → 8-port 802.3af/at, budget 65 W, unmanaged
- 8 cameras / company → 16-port 802.3at, budget 150 W, managed L2
- 16+ cameras / industrial → 24-port 802.3at, budget 300 W, managed L2+
All our PoE switches are in the PoE switches category.
Most common mistakes
- ❌ Insufficient budget — "I have 8 ports, so I power 8 cameras" — not always true
- ❌ Wrong standard — cheap 802.3af switch for a PTZ camera = doesn't work
- ❌ Long cables >100 m — power drops, PoE extender required
- ❌ Poor UTP — Cat5 (not Cat5e) can cause power losses
For a detailed calculation of your project use our camera-system configurator or write to us — we'll be glad to advise.