I have been spending a little time in my server cabinet downstairs, trying to organize some things. I took what I thought would be a quick step in consolidation. It was not as quick as I had hoped.
POE Troubles
When I got into the cabinet, I realized I had 3 POE injectors in there, powering my three Unifi Access Points. Two of them are the UAP-AC-LR, and the third is a UAP-AC-M. My desire was simple: replace 3 POE injectors with a 5 port PoE switch.
So, I did what I thought would be a pretty simple process:
- Order the switch
- Using the MAC, assign it a static IP in my current Unifi Gateway DHCP.
- Plug in the switch.
- Take the cable coming out of the POE injector and plug it into the switch.
And that SHOULD be it: devices boot up and I remove the POE injectors. And, for two of the three devices, it worked fine.
There’s always one
One of the UAP-AC-LR endpoints simply would not turn on. I thought maybe it was the cable. So I checked the different cables, but still nothing. I swapped out the cables and nothing changed: the one UAP-AC-LRs and the UAP-AC-M worked, but the other UAP-AC-LR did not work.
I consulted the Oracle and came to realize that I had an old UAP-AC-LR, which only supports a 24v Passive PoE, not the 48v standard that my switch supports. Obviously, the newer UAP-AC-LR and the UAP-AC-M have support 802.3at (or at least a legacy protocols for 48v), but my oldest UAP-AC-LR simply doesn’t turn on.
The Choice
There are two solutions, one more expensive than another:
- Find an indoor PoE Converter (INS-3AF-I-G) that can convert the 48V coming from my new switch to the 24v that the device needs.
- Upgrade! Buy a U6 Pro to replace my old long range access point.
I like the latter, as it would give me WiFi 6 support and start my upgrade in that area. However, I’m not ready for the price tag at the moment. I was able to find the converter for about $25, and that includes shipping and tax. So I opted for the more economical route in order to get rid of that last PoE injector.
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