How to troubleshoot the ineffective long-distance power supply of ES switches?

Fault Phenomenon:
ES POE Switch cannot power PD devices (such as cameras and APs) in long-distance (>100 meters) scenarios
Short-distance tests are normal, only long-distance tests fail
1.Check whether Long Distance Transmission enabled

2.Check cable quality and length
Choose Monitoring > Cable Diagnostics.
Cable diagnostics allows you to check the status of Ethernet cables. For example, you can check whether the cables are short-circuited or disconnected.
Select the ports you want to detect, and then click Start to start cable diagnostics. The test result will be displayed accordingly. Click Start All to perform one-click cable diagnostics on all ports.

Note:This check needs to be done in the web.
1) Measure the length of the network cable on-site (ensure it is no more than 250 meters)
2) Replace Cat6/Cat6a network cables (essential for long-distance use)
3) Avoid bending the cables or placing them close to interference sources
3.Verify PoE power distribution
Check the real-time power and remaining power budget

If the power is insufficient: reduce other PD devices on the same switch or upgrade to a higher-power model
Ensure that the power of the PD device ≤ 30W (IEEE 802.3at standard)
4.Confirm the compatibility of the power supply wire sequence
ES Series Adopts Mode A (Power Supply for Line Pairs 1-2, 3-6)
1)Consult the PD device manual to confirm the supported power supply modes
2)Test PD devices of other brands (excluding compatibility issues)
Solution:
When incompatible: Use a PoE injector or replace the PD device
5.Environment and Hardware Detection
1)Check the ambient temperature (protection will be triggered if it exceeds 45°C)
2)Observe the status of the port LED:
3)Mode 2 (PoE Status): Solid green light = Power supply in progress, Flashing = Overload
Solution :
1)Improve heat dissipation (ensure ≥10cm space around the device)
2)If the LED is blinking abnormally: Contact technical support