PoE Explained: Powering Cameras, APs and Phones Over One Cat6 Cable

By Cabling For U, Auckland network cabling installers since 2018.

Power over Ethernet (PoE) is the quiet revolution in commercial cabling. One Cat6 cable carries both data and up to 90W of power — enough for a ceiling AP, a PTZ camera, a VoIP phone, a video doorbell, or a tablet-sized building controller. Here’s what an Auckland business owner needs to know.

What does “PoE” actually mean?

PoE delivers DC power over the same twisted-pair cable that carries Ethernet data. No separate power adapter, no extra GPO at the ceiling, no electrician trip for every device. The cable comes from a PoE switch (or a PoE injector) in your comms room and ends at a PoE-capable device like an AP or camera.

The PoE flavours and what they power

• PoE (802.3af): up to 15.4W at the source, ~12.95W at the device. Powers VoIP phones, basic cameras, simple APs.
• PoE+ (802.3at): up to 30W at source, ~25.5W at device. Powers Wi-Fi 6 APs, PTZ cameras, tablets.
• PoE++ / Type 3 (802.3bt): up to 60W at source, ~51W at device. Powers Wi-Fi 6E APs, high-end PTZ with heaters, small thin clients.
• PoE++ / Type 4 (802.3bt): up to 90W at source, ~71W at device. Powers Wi-Fi 7 APs, outdoor cameras with heaters, small laptops, digital signage.

How much PoE budget do you need?

A common mistake is to count devices but forget switch capacity. Example:

• 24 ports × 30W each = 720W of requested power
• But the switch PoE budget might only be 370W
• Result: some ports don’t power up, or power cycles randomly under load

Plan switch PoE budget first, then device count. We’d rather install a slightly bigger switch than have you call back in six months about a mystery reboot.

Cabling implications

• Cat6A is safer for high-power PoE — lower conductor resistance, runs cooler under load
• Bundle sizes matter — tight bundles of 24+ PoE cables in a warm ceiling void can exceed cable temperature ratings
• Run length matters — longer runs waste more power as heat; at 90 m you can lose 15–20% of delivered power
• Quality matters — cheap “CCA” (copper-clad aluminium) cable fails dramatically under PoE load; always spec solid copper

For more on our cable spec see structured cabling.

Common PoE use-cases

• Wi-Fi APs — a ceiling AP on PoE++ avoids extra GPO costs
• IP cameras — no separate 12V DC supply needed
• VoIP desk phones — the original PoE use-case, still huge
• Access control readers and electric strikes
• Building sensors and IoT hubs
• Digital signage — small-to-medium screens

Switch selection tips

• Pick a switch with total PoE budget ≥ sum of device requirements + 25% headroom
• Managed switches let you cap per-port PoE to prevent runaway load
• Consider a multi-gig switch (2.5GbE/10GbE) if you’re running Wi-Fi 7 APs
• Most small-business switches from reputable vendors now offer 8–24 port PoE++ models at reasonable prices

Typical Auckland PoE-dependent install costs

• 8-port PoE switch + 4 cameras + 2 APs: $3,500–$6,000 installed
• 24-port PoE++ switch + 12 cameras + 4 APs + phones: $9,000–$15,000
• 48-port managed PoE++ switch + 30 cameras + 10 APs for medium office: $18,000–$30,000

Frequently asked questions

Can any Ethernet cable carry PoE?

Most modern Cat5e, Cat6 and Cat6A cable can carry PoE up to PoE+ (30W). For PoE++ / 60W or 90W, use Cat6 or preferably Cat6A solid copper. Avoid copper-clad aluminium (CCA) cables entirely — they fail under PoE load.

How far can PoE run before power drops off?

PoE standards guarantee power delivery up to 100 metres. At that distance, cable resistance can reduce delivered power by 10 to 20%. For 90W PoE++ devices at the far end of long runs, oversize slightly and use Cat6A to minimise losses.

Do I need a PoE injector or a PoE switch?

For 1 or 2 PoE devices, a single-port PoE injector is fine. For anything more, get a PoE switch - cleaner cabling, central management and total PoE budget you can monitor. Most Auckland small business installs use a managed PoE switch as the default.

Is PoE safe?

Yes. PoE runs at 48 to 57V DC with current limiting that prevents fire or shock. The IEEE 802.3 standards include mandatory detection that only powers a port after confirming a compatible PoE device is attached.

Will PoE devices work on a non-PoE switch?

No. A non-PoE switch won't supply power, so a PoE camera or AP will stay off. You can add a PoE injector between the switch and the device as a workaround but it's not elegant for more than 1 or 2 devices.

How much does it cost to run PoE to one ceiling AP?

A new Cat6A drop from the comms room to a ceiling AP location in an Auckland office typically costs NZD 220 to 360 including cable, termination, testing and pathway. The AP itself and switch port are additional but the cabling is the long-term part.

Planning a PoE deployment?

We’ll spec the switch, cabling, cameras and APs as one system so the PoE budgets balance and the runs are future-proofed. Book a free Auckland site survey or call 0800 222 546.