[ars]

PoE doorbells exist, but are rare.

The issue is that the proper size wire to provide power to a doorbell is larger than a Cat 5 cable. So if you run Cat 5 to your doorbell, you can't actually use it as a simple doorbell. (Cat 5 is 24 gauge, but you need 16 gauge for a doorbell.)

If you are building a house and you want to leave options for the home owner what do you do? PoE Cat 5? Or standard doorbell wire?

The market seems to have decided that you do a standard 16V AC 1A power to the doorbell, and then WiFi for the data.

See: https://support.ring.com/hc/en-us/articles/360041807292-Sele...

[sirmoveon]

I believe that standard comes from the adaptation of conventional doorbells installations. In my opinion, what I see trending, is people wiring their houses for NVR systems with Cat5/6. In this scenario, a simplistic and cheap doorbell hardware, that connects to a PoE NVR and delegates all the object detection there, sounds far more valuable than a supercharged doorbell.

As you said, they exists but are rare (and expensive). It seems to me there is a niche market that nobody is recognizing and taking advantage of.

[ars]

Personally I put in a standard doorbell wire, and then a Cat 5 wire above the door for a camera.

[pklo]

16 gauge is rated for 17A; 24 gauge is rated for 3A. Given that, as you say, the rated current for the doorbell is 1A, I don't understand why 16 gauge is necessary; if you're concerned about shorts, consider that 16A/16V would more likely burn out the transformer before doing anything to the wires because the power density is larger there. Just to be safe, I'd put 3A fuse inline and use Cat5 without reservations.

[jasonjayr]

A doorbell is only 2 wires -- if you pull Cat5 for future proofing, could you bind 2 or 4 of the 8 available wires to safely pull the current? Obviously, the other end can't be plugged into a network switch till it's properly wired up.

I don't have enough electrical know-how to figure out if this works...

Edit: Based on a table I found; 24 gauge wire has a resistance of about 25 ohms per foot, where as 16 gauge has a resistance of 4 ohms per foot. So; assuming each wire is a parallel resistor, 2 pairs(4 wires) would be about 6.25 ohms -- so it could heat up a bit more than proper wires. so .... maybe as long as someone doesn't hold the button down for too long?

[tonyarkles]

*per 1000ft, not per foot

[bombcar]

I suspect you could run PoE over 16 gauge cable, maybe not at gigabit, but good enough.

Or you could run something like this: https://www.cablesforless.com/bundled-cable-cat5e-and-4c-16a...

[ars]

That product is just two cables stuck together. Instead you could just simply run both types of cable to the doorbell, especially since they'll probably go to different places.

I googled a bit and it seems you might be able to run low speed Ethernet over untwisted wires if they are not long.

[jlgaddis]

10BASE-T1{S,L} [0] are "only" 10 Mbps but they also need only a single pair of wires (with the latter working up to 1 km).

They aren't exactly in widespread usage yet, though.

--

(ETA: And apparently there are even 100 and 1000 Mbps variants now too [0] -- with lower maximum distances, of course.)

[0]: https://en.m.wikipedia.org/wiki/Ethernet_over_twisted_pair#S...