With the rapid development of industrial automation and the Internet of Things, PoE (Power over Ethernet) industrial switches are widely used in monitoring, industrial automation control, and other scenarios due to their ability to simultaneously transmit data and power through Ethernet cables. However, in practical use, the problem of insufficient PoE power supply often occurs, seriously affecting the normal operation of the equipment. This article will delve into the power supply function of POE industrial switches, the hazards of insufficient power supply, detection methods, and solutions.
1、 Power supply function of POE industrial switch
POE industrial switches are based on the IEEE 802.3af/at/bt standard and can simultaneously transmit data and power to PoE enabled terminal devices (such as IP cameras, wireless access points, industrial sensors, etc.) through Category 5 or Category 5e Ethernet cables without changing the existing Ethernet network architecture. There are mainly two types of power supply methods:
Standard PoE: Compliant with the IEEE 802.3af/at/bt standard, it transmits power through idle pairs or data transmission pairs of Ethernet cables to ensure compatibility and security of power supply. The maximum output power of each port in the IEEE 802.3af standard is 15.4W, and the power receiving device (PD) can obtain 12.95W; the maximum output power of each port in the IEEE 802.3at standard is increased to 30W, and the PD can obtain 25.5W; the IEEE 802.3bt standard further increases the maximum output power of ports to 60W or 90W
Non standard PoE, also known as "forced power supply", does not comply with IEEE standards and carries risks such as voltage instability and power mismatch, which may damage power receiving equipment. It is less commonly used in the industrial field.
PoE industrial switches have intelligent power management functions, which can monitor and control the power status of each port, achieve remote power supply, power-off, restart and other operations, improve device management efficiency and system stability.
2、 The hazards of insufficient power supply
（1） The device is not functioning properly
When the power supply of PoE industrial switches is insufficient, the most direct impact is that the powered devices cannot obtain sufficient power, resulting in the inability to start or frequent restarts of the devices. For example, IP cameras may not be able to capture and transmit images properly, and wireless access point signals may be unstable or even interrupted, seriously affecting the normal operation of monitoring systems and wireless networks.
（2） Equipment performance degradation
Even if the powered equipment can barely start, insufficient power supply can lead to a decrease in equipment performance. If the data collected by industrial sensors is inaccurate, the transmission rate of wireless devices decreases, the packet loss rate increases, etc., it affects the data collection and transmission quality of the entire industrial system, reduces production efficiency and product quality.
（3） Equipment lifespan shortened
Being in a state of insufficient power supply for a long time, the internal electronic components of the powered equipment will bear additional pressure, accelerate aging and damage, shorten the service life of the equipment, and increase maintenance and replacement costs.
（4） Safety hazards
In some industrial scenarios that require high stability of power supply, insufficient power supply may lead to safety accidents. For example, in hazardous environments such as chemical and mining, monitoring equipment or sensors may not work properly due to insufficient power supply, which may result in the inability to detect safety hazards in a timely manner and cause serious safety accidents.
3、 Detection of insufficient power supply
（1） Observe the status of the equipment
By observing the indicator light status of the powered equipment, determine whether the equipment is supplying power normally. If the device indicator light does not light up or flashes abnormally, it may be caused by insufficient power supply. At the same time, check the working status of the equipment, such as whether the IP camera screen is lagging, whether the wireless access point is frequently disconnected, etc., to preliminarily determine whether there is a problem with the power supply.
（2） Use professional tools for inspection
Use professional tools such as multimeters and PoE testers to measure the voltage and current at both ends of the Ethernet cable, and determine whether the output power of the PoE industrial switch meets the standards. The PoE tester can quickly detect the power supply type, output power, and network cable connectivity of PoE switches, helping to accurately locate the cause of insufficient power supply.
（3） View switch logs
PoE industrial switches typically have logging capabilities. By viewing the system logs of the switch, information such as port power status and power overload can be obtained to determine if there are any abnormal power supply situations. For example, the log may record detailed information about a port experiencing power interruption due to insufficient power, providing a basis for troubleshooting.
4、 Solution to power shortage
（1） Optimize equipment power allocation
Evaluate equipment power requirements: Conduct a detailed assessment of the power requirements of all powered devices to understand the actual power consumption of each device. Accurate data can be obtained through the device manual or by using power measurement tools.
Reasonably allocate ports: Based on the power requirements of the devices, connect high-power devices to PoE ports that support higher power output, and connect low-power devices to regular ports. Avoid multiple high-power devices being centrally connected to the same switch, which may result in insufficient local power supply. For example, connect a high-power industrial camera to a port that supports the IEEE 802.3at standard, and connect a low-power wireless sensor to a port that supports the IEEE 802.3af standard.
Enable port priority: Utilize the port priority function of PoE industrial switches to set higher power priority for critical devices. When the power supply of the switch is insufficient, priority should be given to ensuring the power supply of key equipment to ensure the normal operation of important business.
（2） Add PoE powered devices
Add PoE switch: If the total power of the existing PoE industrial switch cannot meet the needs of all devices, it is possible to consider adding a new PoE switch to distribute the power load of the devices. When adding a switch, it is important to pay attention to the number of ports, power supply standards, and network topology to ensure compatibility and stability between the new switch and the existing network.
Using a PoE power supply: A PoE power supply is an independent PoE powered device that can upgrade a regular switch to a PoE switch. By connecting a PoE power supply between a regular switch and a powered device, power is provided to the device. PoE power supply is suitable for scenarios that require temporary addition of PoE power supply function or power supply to a small number of devices, and has the advantages of easy installation and low cost.
（3） Upgrade PoE switch
If the power requirements of the devices are generally high and the existing power supply standards of PoE switches cannot meet the requirements, upgrading to PoE switches that support higher power output can be considered. For example, upgrading a switch that supports the IEEE 802.3af standard to a switch that supports the IEEE 802.3at or IEEE 802.3bt standards to provide sufficient power support. When upgrading a switch, it is important to backup the configuration data of the original switch to ensure a smooth transition of the network.
（4） Check and optimize network cabling
Check the quality of the Ethernet cable: The quality and length of the Ethernet cable can affect the transmission distance and stability of PoE power supply. Use qualified Category 5 or Category 5e Ethernet cables and avoid using excessively long or aged cables. Generally speaking, the effective transmission distance of PoE power supply is within 100 meters. If it exceeds this distance, it may lead to insufficient power supply. For power receiving devices that are far away, the solution can be to install a PoE relay in the middle or replace it with fiber optic transmission.
Optimize wiring method: Reasonably plan network wiring to avoid situations such as excessively long, tangled, and knotted network cables, and reduce line losses. At the same time, ensure that the network cable is firmly connected to avoid unstable power supply caused by poor contact.
（5） Strengthen equipment maintenance and management
Regular inspection of equipment status: Establish a regular inspection system to check the operation status of PoE industrial switches and powered devices, and promptly detect and handle power supply abnormalities. For example, check the port power status, device temperature, and heat dissipation of the switch once a month.
Update device firmware: Timely update the firmware version of PoE industrial switches, fix known power supply issues and vulnerabilities, and improve switch stability and compatibility. At the same time, ensure that the drivers and firmware of the powered devices are also kept up to date to fully utilize the performance of the devices.
The above provides various methods to address the insufficient PoE power supply in industrial switches. You can tell me if these contents meet the requirements, and if there are specific scenarios or other requirements, you can also tell me to further improve them.