PoE Explained: Powering Cameras, Access Points & Intercoms
Essential Security Supplies
Power over Ethernet (PoE) has become the standard delivery method for powering IP security devices across commercial and industrial installations throughout New Zealand. By combining data and power over a single Cat5e or Cat6 cable, PoE eliminates the need for separate power runs to each device, reducing installation time, cost, and ongoing maintenance overhead. Whether you are deploying IP cameras, wireless access points, or IP intercoms, understanding PoE standards, power budgets, and device compatibility is essential for a reliable installation.
How PoE Works: Data and Power Over a Single Cable
PoE uses the spare wire pairs or the active data pairs in a standard Ethernet cable to deliver DC power from a PoE-capable switch or injector to a powered device (PD). The power sourcing equipment (PSE) - typically a PoE switch or midspan injector - detects whether the connected device supports PoE before delivering power, preventing damage to non-PoE equipment.
The IEEE has standardised multiple PoE variants, each with different power outputs:
| Standard | IEEE Designation | Max Power at PSE | Max Power at PD | Typical Use Cases |
|---|---|---|---|---|
| PoE | IEEE 802.3af | 15.4W | 12.95W | Basic IP cameras, VoIP phones |
| PoE+ | IEEE 802.3at | 30W | 25.5W | PTZ cameras, wireless APs, IP intercoms |
| PoE++ | IEEE 802.3bt Type 3 | 60W | 51W | High-power APs, pan-tilt cameras, thin clients |
| PoE++ | IEEE 802.3bt Type 4 | 100W | 71.3W | High-power devices, displays, video conferencing |
For professional security installations, PoE+ (IEEE 802.3at) is the most commonly specified standard. It covers the majority of IP cameras, access control readers, and IP intercoms deployed in commercial environments across New Zealand.
Powering IP Cameras with PoE
IP cameras are the most common PoE-powered devices in security installations. Fixed dome and bullet cameras typically draw between 5W and 12W, well within IEEE 802.3af limits. PTZ cameras, high-resolution multi-sensor units, and cameras with integrated heater/fan assemblies often require PoE+ at up to 25.5W at the device.
The CIR-BA37NAC from IR Lab is a 3MP PoE bullet camera suited to perimeter and entry monitoring. For higher-resolution requirements, the Dahua IPC-HDPW5541G-Z delivers 5MP resolution with varifocal capability across a 2.7-13.5mm range.
For licence plate and ANPR applications, the UniView HC121-TS8CR-Z provides 2MP 1080P PoE-powered ultra-low-light capture with 50m IR range, making it a strong option for vehicle entry points and car parks.
When specifying cameras, always confirm the device's power draw against your switch or injector's per-port budget. A PoE switch with a 300W total budget shared across 24 ports cannot simultaneously supply full PoE+ to every port.
Powering Access Points with PoE
Wireless access points for commercial and industrial deployments almost universally require PoE+ (802.3at) or PoE++ (802.3bt). Enterprise-grade APs with multiple spatial streams, integrated Bluetooth, and multi-radio configurations frequently draw 25W or more. Specifying an 802.3at-capable switch port or injector for every AP location ensures headroom for peak power demand and firmware-triggered feature activation.
For outdoor AP deployments - common in warehouse and yard environments - verify the AP enclosure's IP rating matches the installation environment. The IEEE 802.3bt standard documentation outlines the technical requirements for PoE++ deployments where higher power APs are specified.
Where a switch port with PoE capability is unavailable at the AP location, a midspan injector provides a point-solution that converts an existing non-PoE switch port to a PoE-capable output.
The TP-Link TL-POE380S Omada 10G PoE++ Injector delivers up to 95W on a single 10G port, making it suited to high-draw APs and devices that exceed standard PoE+ limits. View our product range of PoE injectors and splitters for single-port and multi-device options.
Powering IP Intercoms with PoE
IP video intercoms and door stations are increasingly PoE-powered, particularly in multi-tenant residential and commercial access control installations. A typical single-unit IP door station draws between 10W and 20W, placing it within PoE+ range. Intercom master stations with touchscreens or integrated displays may draw up to 30W and require a confirmed PoE+ source.
Key installation considerations for PoE-powered intercoms include:
- Maximum cable run of 100m per IEEE standard from the PSE to the intercom station
- Cable quality - use a minimum of Cat5e, with Cat6 preferred for longer runs
- Confirming whether the intercom requires a dedicated PoE port or supports passive PoE (non-standard voltage) - these are not interchangeable
- For installations where the IDF or switch is more than 100m from the door station, a PoE long-reach extender can extend both data and power up to 1km over a single cable pair
PoE Switches vs Injectors vs Splitters: Choosing the Right Solution
Understanding the difference between PoE delivery methods is critical for correct specification:
- PoE Switch - a network switch with built-in PoE on each port; the preferred solution for multi-device deployments where all devices are co-located. Offers centralised power management and monitoring.
- Midspan PoE Injector - adds PoE to a single non-PoE switch port; suited to single-device additions or where upgrading the switch is not viable. The Edimax GP-101IT-c IEEE 802.3at Gigabit PoE+ Injector is a compact single-port option for 30W PoE+ requirements.
- PoE Splitter - placed at the end device to separate power and data where the device does not support PoE natively. The Edimax GP-101ST Gigabit PoE+ Splitter provides adjustable 5V, 9V, or 12VDC output, accommodating a range of device power requirements.
Cable Distance and PoE Performance
The IEEE 802.3 standard specifies a maximum Ethernet segment length of 100m (328ft) for copper Cat5e or Cat6 cable. At longer distances, voltage drop across the cable reduces the available power at the end device. This becomes critical for high-draw devices such as PTZ cameras and heated outdoor cameras in cold-climate installations.
For installations requiring PoE delivery beyond 100m, the CTS PLR-2012-KIT Long Reach Extender extends both RJ45 data and PoE power up to 1km over a single cable pair - eliminating the need for additional power infrastructure at the remote device location. This is particularly relevant for gate entry cameras, remote car park bollards, and intercom stations at building perimeters.
Product Specifications
| Specification | Detail |
|---|---|
| PoE Standard (802.3af) | 15.4W per port at PSE / 12.95W at PD |
| PoE+ Standard (802.3at) | 30W per port at PSE / 25.5W at PD |
| PoE++ Standard (802.3bt) | 60W (Type 3) or 100W (Type 4) per port at PSE |
| Max cable run (standard) | 100m Cat5e/Cat6 (IEEE 802.3) |
| Max cable run (long reach) | Up to 1km with PLR-2012-KIT extender kit |
| Edimax GP-101ST Splitter output | Adjustable 5V / 9V / 12VDC; Gigabit PoE+ |
| Edimax GP-101IT-c Injector | IEEE 802.3at; 30W; Gigabit throughput |
| TP-Link TL-POE380S Injector | IEEE 802.3bt; 95W; 10G port; Omada compatible |
| YN8416 Micro USB PoE Splitter | 5V Micro USB output; compact form factor |
| Typical IP camera draw | 5-12W (fixed); up to 25.5W (PTZ/heated) |
| Typical IP intercom draw | 10-30W depending on model and screen size |
View our product range for full model-specific specifications and current availability.
Specifying PoE for Your Installation
A correctly specified PoE deployment starts with a device power budget. List every PoE-powered device, confirm its IEEE standard and worst-case power draw, then total the aggregate. PoE switches and injectors carry a rated total power budget - for example, a switch rated at 250W across 24 ports cannot sustain 24 x 25.5W PoE+ devices simultaneously. Apply a 20-30% headroom buffer to the total switch budget to account for device startup surges and future additions.
For large-scale deployments with mixed PoE, PoE+, and PoE++ devices, managed PoE switches that support per-port power prioritisation and monitoring provide significantly better control than unmanaged alternatives. Where installations span large distances or buildings, PoE extenders, fibre uplinks with media converters, and structured cabling infrastructure become part of the design scope.
Essential Security Supplies stocks a comprehensive range of PoE infrastructure products suited to commercial and professional installations throughout New Zealand - from single-port injectors through to high-capacity managed switches and long-reach extenders. View our PoE switch range to find the right solution for your project.
