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Power over Ethernet (PoE) basics and beyond

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257 points voxadam | 5 comments | 16 Oct 25 14:09 UTC | HN request time: 0.448s | source
1. brcmthrowaway ◴[22 Oct 25 00:43 UTC] No.45663665[source]▶
1. Why are IEC/Edison cables so thick if Ethernet can carry the equivalent power?

2. How does PoE compare to Powerline Networking?

replies(2): >>45663680 #>>45663710 #
2. otterley ◴[22 Oct 25 00:46 UTC] No.45663680[source]▶
No Ethernet cable that I’m aware of is capable of carrying anywhere near 15A of current. Even type 4 (90W assuming 57V) is 1.5A.
replies(1): >>45669183 #
3. skinner927 ◴[22 Oct 25 00:51 UTC] No.45663710[source]▶
1. Assuming IEC refers to cables we plug a desktop PSU into mains/wall: IEC can carry up to 1800w vs 100w PoE++

2. Powerline networking is considerably slower and less reliable than CAT5/6. Additionally, building code for running power lines is much more strict than low voltage CAT5/6

replies(1): >>45665314 #
4. dlgeek ◴[22 Oct 25 05:50 UTC] No.45665314[source]▶
Nerdsniped: You're describing a IEC 60320 C13 cable - they're technically only spec'd for 10A, which means you're looking at ~1200W, not 1800.

(However, UL will list them for the full 15A -> 1800W, and I'm sure plenty carry that. And for that matter, I suppose you can get twice that in Europe on 240v...)

5. gwbas1c ◴[22 Oct 25 13:52 UTC] No.45669183[source]▶
And don't forget that, with ethernet, every device needs its own run of cable, its own port at the router, ect, ect. Normal power cables support multiple devices.