I have very little, close to none experience with Passive PoE.
My main router is hAP ax3. I’m trying to extend wireless coverage with cAP (ac/ax), but I can’t understand if powering cAP directly from hAP ax3 is a viable option.
I don’t have any cAP on hands. Just exploring options.
Please advise. Thanks!
P.S.
My way of thinking goes like this:
hAP ax3
AC adapter: 24 V * 1,5A (36W)
DC jack input Voltage: 12-28 V
Max total out: 0.625 A
Total output power: 15 W (?)
If I divide 15 W by 0.625 A I’m getting output Voltage = 24 V (which kind of makes sense and corresponds with my AC adapter)
cAP ax
PoE in: 802.3af/at
PoE in input Voltage: 18-57 V
Max power consumption without attachments: 9W
Putting all together
Voltage: 24 V (hAP ax3) falls into 18-57 V range (cAP ax)
Power: 15 W (hAP ax3) is enough to cover 9W (cAP ax)
The only thing you’re missing is that max power consumption of hAP ax3 (with attachments, I’m assuming this includes PoE out) is 38W which slightly exceeds output of included power adapter (36W). But most probably this worst case won’t ever happen.
One other remark:
POE in/out on AX3 is on the same port: ether1.
Default config on AX3 ether1 is used as WAN.
If you use it to power cAP, you will have to change your config to bring WAN on another port.
Not complicated or so but simply something to take into account.
Also, that same ether1 is the only port on AX3 capable of 2.5G-ethernet.
I have similar situation.
Mains routers are RB5009 and AP are AX3 and AC3. At this time, no more money to buy mkt switches with a good poe backend.
So i use POE injecter (foolow link here) designed to provide 24V and gigabit. This is possible because my trunk links for AP are ETH1 with allow POE-IN
So all PSU are at the same places and AP are hidden.