My Unifi 6 Enterprise is rebooting when connected to my RB5009UPr+S+IN, but only in high power situations. It happens when it is running speed tests on the 6 GHz band. There seem to be no relevant logs on either side, except for the Mikrotik reporting that ether1 is down and the current is too low (I think due to the AP shutting off). To the U6 Enterprise, the logs look as if it suddenly shuts off with no warning.
It looks like the power draw spikes to 20W+ and then the AP reboots. It seems kind of like it’s drawing too much current for the router to handle.
The spec sheets says the max output per port is 420 mA from 30-57V. At 48V this is just a little over 20W. Even at 57V, this is just shy of 24W.
However elsewhere on the page, it says the max output per port is 25W. Which is it? The U6 Enterprise requires exactly 25W and seems to demand it in my 6 GHz case.
For my other PoE devices connected to the router, combined with 20W for the router itself, I am well under the limits of the 48V/96W power supply supplied with the RB5009UPr+S+IN. I don’t think it’s likely it’s the overall load on the power supply.
I’ve already tried many different high quality cables of various vendors and lengths, from short to long. I bought a 30W 2.5G PoE injector for it to debug further, but it’s not an ideal solution in the end and would love to get it to work with just the router.
The fact it works with power injector and that other devices keep working, does seem to indicate that Unifi 6 Enterprise is drawing too much power from that port during those tests.
If there would be a total overload, the complete RB5009 would be taken down.
If you have a power or current meter, you can use it on power injector with U6 Enterprise to see how much power/current that unit draws during full test ? (there will be some overhead from the injector itself, but that you can measure and subtract from the total).
The u6 ships with a 48v/.5a injector while the 5009 would provide 48v/.42a max. The u6 states the max power consumption would be 22w, which is more than what the 5009 with the default power supply can provide.
You should probably look for a 57v/2a power supply (a 53v/2a might work) to power your 5009/aps.
You might be able to drop the power on your radios to get by, but a better power supply would be best.
Thanks for the replies. I actually don’t have the PoE injector yet, it’s coming from Amazon next week, so I’ll give it a shot.
The AP is a U6 Enterprise which unfortunately doesn’t ship with an injector and actually uses even more power than the other U6, at 25W. I suppose a 57V power supply might work but still would not provide the full 25W the U6 Enterprise is rated for.
Transmit power at Medium or Low still doesn’t work unfortunately.
That one is 48v, and given the RB5009Upr has a max amps per port of 0.42a would mean 20.16w max to one device.
I found 56v2a on AliExpress but do not know of quality. https://www.aliexpress.com/item/1005004351622364.html
I wouldn’t use that PSU… router and devices connected to it are much more expensive… Search for NPB-240-48TB, it says it’s adjustable from 42V up to 60.2V
An update, since I forgot to update the thread. It turns out the combination of the router and the power supply is just not enough for the U6 Enterprise’s 6 GHz mode.
I got the TRENDnet 2.5G PoE+ Injector and it works great on the same port, the U6 Enterprise no longer shuts down when serving a 6 GHz client. It’s certainly not as clean as powering everything from the RB5009.
My guess is the RB5009 will shut down the port when it draws too many amps.
I gave up searching for a higher voltage power supply.
Upping this topic.
Did anyone find any improvements?
Is it worth trying to feed U6 enterprise from 5009’s PoE or would I be better off ordering a separate PoE injector?
There is nothing you can do if a device draws too much power from RB5009 except for inserting a power injector to protect that RB5009 from being taken down.
There are things you can do actually.
Especially if it wants to draw only marginally more power and only in some edge cases and for a short amounts of time.
You can make it so that it wants less power by changing certain settings, for example.
Or you could try using a power supply with more voltage than the stock one rb5009 comes with.
Thought about that as well.
But I think I’ll just try an AP without any extra hardware. See if I’m lucky. // because I don’t have a spare PSU on hand
If not - I will probably just buy a PoE injector.