PoE+ power issues on ~90m Cat6 run — need advice

Hank Weng

n3wb
Aug 26, 2025
14
6
Taipei
I’m running into an issue with PoE on a home setup. The cable run is close to 90m (Cat6, solid copper) and the camera sometimes reboots randomly. The switch is PoE+ (802.3at), and on paper it should be fine with the camera’s 12W draw, but I’m guessing voltage drop is the problem.

Has anyone here dealt with similar situations? Would you recommend adding a mid-span injector/repeater, or is it safer to upgrade to a PoE++ (802.3bt) switch?

Any real-world tips would be appreciated — not sure if I’m overthinking it or if this is a common issue.
 
I run a few cameras at the end of runs approaching the 100m limit, and one at 400 feet, with no reboot problems. The camera on the 400 foot run is a T180 that has a spec'd maximum draw of 11.8 watts. By the numbers, I don't think there should be a power problem due to the wire length. The round-trip resistance using 23 awg solid copper is 6.678 ohms (from an awg chart). At 12 watts you're drawing about a quarter amp, for a voltage drop of 1.67. I'd expect the camera to be easily tolerant of that. Do the reboots happen only when your cameras are drawing the most power, i.e. when the IR lights are running? If that's the case one suspect would be that you've reached to total power capability of the switch. If it happens during the day also, you could be looking at a cable termination problem, or flaky camera. I'd be swapping components to isolate where the failure is, like running a separate temporary cable to the camera, swapping the camera, different switch port, and so on.
 
I’m running into an issue with PoE on a home setup. The cable run is close to 90m (Cat6, solid copper) and the camera sometimes reboots randomly. The switch is PoE+ (802.3at), and on paper it should be fine with the camera’s 12W draw, but I’m guessing voltage drop is the problem.

Has anyone here dealt with similar situations? Would you recommend adding a mid-span injector/repeater, or is it safer to upgrade to a PoE++ (802.3bt) switch?

Any real-world tips would be appreciated — not sure if I’m overthinking it or if this is a common issue.
1. Not copper-clad aluminum (CCA) +1 point
2. Cat6 +1 point

Could be a few minor things:
a) swap PoE ports on the switch and see if the problem follows the camera - if it still occurs on other PoE ports, it's most likely at the camera
b) get some high-quality RJ-45 plugs made for solid wire (not for stranded!) and re-terminate both ends of the cable. Don't need to cut off a lot, maybe an inch or two from either end.
c) if problem STILL persists, and STILL follows the camera, then it's likely a bad PoE circuit board in the camera. Managed PoE switches could tell you via software what the current and voltage draw are, or you could use a hand-held meter to check the voltage at the camera end.

Hope this helps.
 
For CAT6 there is procedure for proper termination if 1Gb network is used but for 100Mb is not that important, but make sure you use CAT6 RJ45 plugs as the wire is thicker and standard CAT5 RJ45 may cut the wire off when terminating. Use network cable tester to make sure the connection is good.
One more suggestion is to supply power to camera from 12V battery for testing if the problem is due to POE as external power take precedents over POE
 
I’m running into an issue with PoE on a home setup. The cable run is close to 90m (Cat6, solid copper) and the camera sometimes reboots randomly. The switch is PoE+ (802.3at), and on paper it should be fine with the camera’s 12W draw, but I’m guessing voltage drop is the problem.

Has anyone here dealt with similar situations? Would you recommend adding a mid-span injector/repeater, or is it safer to upgrade to a PoE++ (802.3bt) switch?

Any real-world tips would be appreciated — not sure if I’m overthinking it or if this is a common issue.

is the cable 23AWG?

this is more important than cable is CAT5 or CAT6...

You can try to use different switch, but POE++ will not solve any problem here (because camera will negotiate POE+ only)..
Also POE+ and POE++ are using the same voltage...

Both HIK & Dahua are offering own POE switches, for camera installations on long cable runs.. Dahua is calling this ePOE and most Dahua cams is supporting this... Also better/higher models Dahua NVRs supports ePOE on first 8 ports...

Andy is his shop have only small one (8 port), but you can easy to find bigger models with ePOE..


Is you are using HIK (or other manufacturers) cams, you should choose switch solution for that company (they aren't compatible)..

Google AI:
What is dahua ePOE?
Dahua's ePoE (Enhanced Power over Ethernet) is a patented technology that extends the transmission range of traditional PoE by transmitting power, video, audio, and control signals over a single network cable for up to 800 meters (or 300 meters at 100Mbps), greatly exceeding the standard 100-meter limit. It simplifies installation for large-scale systems, reduces costs by eliminating the need for intermediate repeaters, and enables the cost-effective migration of old analog systems to modern IP systems using existing coaxial cables with a special adapter.
 
+1^^^ regarding the gauge of the conductor being 23 AWG is more desirable than being CAT5 or 6. :cool:
 
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