need help network CAT6 or cat6a about POE

[gopala]

need help network CAT6 or cat6a about POE length

 

i think few month ago or 1 year ago youtube Linus Tech Tips 

 

 

no found POE Meter length CAT5 CAT6 CAT6A 

i think other video that his Linus Tech Tips 

 

which video they showed about CAT5 OR CAT6 OR CAT6A OR CAT7 about Meter length POE

daam i want rewatch youtube unable to find due too long already few month ago or 1 year ago

 

if you foud youtube video share link must be Linus Tech Tips only

 

 

[Electronics Wizardy]

I'm pretty sure the cat specs are for frequency only, and don't have requirements for wiregague or poe.

 

How much power are you pushing over poe? If your using standard poe or poe+ your probably fine with basically any cable these days, but with something like poe++ check the gague of cables. But I've ran poe++ on a lot of weird cables without issues. Make sure to avoid CCA cables though.

 

 

[mariushm]

You get PoE (power over ethernet) up to 100 meters , the maximum length of a cable you can have.  How much power you end up with at the end of the cable it's another story. 

 

Cat5 , Cat5e , Cat6, Cat6a ... these standards are all about the bandwidth of the wires, how well the pairs are shielded from each other, to get fast speeds.

 

Majority of ethernet cables are made with AWG24 thick wires, 8 wires, arranged in 4 pairs. There's cables which are made with thicker AWG23 wires, and there's also the opposite.

 

A 10 meter Cat6a patch cable could be made with AWG26 or AWG28 wires (thinner) and meet or exceed the bandwidth requirements and easily transfer 10gbps through it, but it would not be a good cable to transfer a lot of power through it, because the wires are thin. 

There's even those FLAT cat6a ethernet cables that use AWG30 wires (even thinner) and they still can do 10 gbps, but they'll be lousy at carrying power. 

 

So the amount of power you can get over the cable depends on : what poe standards are supported by the device sending power , what poe standards the receiver supports, and then depending on cable the receiver will potentially get less power than it asked...

 

For example with 802.3af, the sender can send 44v ... 57v  up to 15.4 watts  (44v x 0.35A = 15.4 watts), and it's acceptable according to standard to have as little as 37v at the end of the cable, which means the maximum power will be around 37v x 0.35A = 12.95 watts 

The device at the end of the cable will then convert this 37v ... 57v down to whatever voltage it needs, and if the 13w maximum is enough, you'll have a working device. Otherwise, you'd have to use a shorter cable or a cable with thicker wires, to reduce as much as possible the losses in the cable. 

 

[johnt]

I’m sure there is cheaper and better, but I installed this stuff all throughout my attic and exterior conduits. POE works perfectly at every wire. My longest run was probably around 35m, maybe a bit less. Not a single problem with the wire except terminations. They are thick at 23awg, but they do crimp snug into RJ45. But I would get a wire straightener to save your fingers no matter what cable you buy.

 

Also, we have cat6 cable at work with runs exceeding 100m and our POE phones all worked. So I’m not sure it matters a whole lot. Your devices rarely use what they claim for max usage. Most people don’t push APs, cameras, phones, key cards so their limits. 
 

https://a.co/d/d0n1l8o

[Lurick]

13 hours ago, johnt said:

Also, we have cat6 cable at work with runs exceeding 100m and our POE phones all worked. So I’m not sure it matters a whole lot. Your devices rarely use what they claim for max usage. Most people don’t push APs, cameras, phones, key cards so their limits. 

It's not about pushing to the limit, it's about electrical impedance over the distance and luck. On devices that conform to the spec* you are guaranteed 100m of distance. Anything beyond that is never a guarantee. It might work to 101m and throw errors on the ports left right and center or it could go to 125 meters without issue for a decade.

 

*I've seen cheap switches for home use which can't even push data over 30m+ because of crappy design and electronics inside the switch and they don't really care about spending the extra few pennies on proper designs.