Power-over-Ethernet (PoE) has transformed the way we power and connect IP cameras. The vast majority of IP cameras and installations today leverage PoE due to its cost-effectiveness and streamlined setup. This technology enables the transmission of both electrical power and data signals over a single Ethernet cable, eliminating the need for separate power supplies and cables.
In this guide, we break down how PoE works, addressing its use cases, standards, and practical considerations.
Jump to each section to learn more
• What is PoE and how does it work?
• Benefits of PoE for security cameras
• Additional PoE Considerations
What is PoE and how does it work?
Before the advent of PoE, every device connecting to an internet or LAN network needed two separate cables for operation: one for data transmission via Ethernet and another for the electrical power supply.
PoE is a technology designed to utilize a single wired Ethernet cable for both data and power delivery to a device. This consolidated approach reduces the infrastructure complexity an organization needs to oversee, as it eliminates the necessity for two distinct cables, streamlining the setup considerably.
PoE operates by sending direct current (DC) electrical power and data signals over standard Ethernet cables. This is achieved through the use of a PoE injector or PoE switch, which injects power into the Ethernet cable so that a compatible PoE-enabled device, such as a security camera, can receive and use the power. With PoE, you only need one Ethernet cable for both data and power. This reduces cable clutter and streamlines the installation process.
When discussing PoE, it’s crucial to grasp the below terminology:
Power Sourcing Equipment (PSE): Devices like switches, midspans, and NVRs that provide power to connected devices.
Powered Device (PD): Devices such as IP cameras, access points, and controllers that receive power from PSEs.
PoE Standards
PoE adheres to IEEE standards, which include:
PoE (802.3af): Provides up to 15.4 watts of power to devices.
PoE+ (802.3at): Offers up to 30 watts of power, suitable for devices with higher power requirements.
PoE++ (802.3bt): Provides up to 60 or 100 watts of power, ideal for power-hungry devices like PTZ cameras or access points.
PoE Negotiation
When a PD connects to a PSE, a quick negotiation process takes place to determine the correct voltage, wattage, and class.
As a result of the initial negotiation process, PoE power remains inactive until a connected device actively requests it. Consequently, a cable linked to a PSE remains non-electrified until it is connected to a PoE-enabled device. This ensures safety and eliminates any risk of incidental contact leading to electrical hazards.
Benefits of PoE for security cameras
PoE offers numerous tangible benefits when it comes to the installation, upkeep, and overall performance of your security camera system.
Enhanced Flexibility and Expanded Camera Placement Possibilities
With PoE cameras drawing power through the ethernet cable, proximity to electrical outlets becomes less important. This allows for a wider array of camera placement options as cameras are no longer tethered to electrical sources. Additionally, relocating or repositioning cameras is a straightforward process, requiring only the adjustment of the ethernet cable.
Cheaper Installation Cost
PoE installations only require one cable and can be completed by almost anyone.
Improved Scalability
In comparison to traditional power-wired cameras, PoE cameras offer more straightforward scalability. Expanding your security camera network can be done simply by incorporating additional network connections.
Enhanced Power Dependability
With PoE, you benefit from a unified and centralized power source, eliminating the need for various wall adapters. Additionally, you have the option to establish an uninterruptible power source (UPS) for your PoE switch, guaranteeing continuous camera operation, even in the event of a power outage.
Elevated System Safety
When utilizing high-quality components, PoE is engineered for secure and efficient power delivery. PoE devices maintain consistent power levels throughout the product’s lifespan to prevent overload or under-powering. Advanced PoE solutions incorporate protective mechanisms against short circuits and excessive current, rendering them substantially safer than conventional outlet-powered systems.
Additional PoE Considerations
1. Power Budget:
Ensure your PoE switch or injector has an adequate power budget to support the connected devices. Cameras with higher power requirements will need switches that can deliver PoE+ or PoE++.
2. Cable Length:
PoE has distance limitations of 100 meters (328 feet). Ensure your cable lengths don’t exceed this limit to maintain connection delivery.
3. Device Compatibility:
Not all cameras support PoE. Verify that your security cameras are PoE-enabled before purchasing a PoE switch or injector.
4. Network Load:
Consider the total power draw on your network. Overloading a PoE switch can lead to performance issues.
5. Redundancy:
For critical applications, consider redundancy options to ensure continuous power in case of switch or injector failures.