POE injector for Unifi AC Pro?

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steve98

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#288841 27-Jul-2021 12:08

I currently have a Unifi AC Lite which came with a POE Injector

Would that same POE Injector power a AC Pro? If not, would this work (or can you point me to something that would)? https://www.pbtech.co.nz/product/NETUBI91105/Ubiquiti-U-POE-af-Passive-PoE-Injector-Only-work-w

Cheers!

OzoneNZ

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#2750588 27-Jul-2021 12:35

Pretty certain that UAP-AC-PRO models are all 48V 802.3af (active) PoE

Earlier UAP-AC-LITE models only came with 24V passive injectors so you should check the box of your UAP-AC-LITE to see if it lists support for 802.3af.

I'd be very careful to confirm that your existing injector from the UAP-AC-LITE is not one of the 24V passive ones before trying to use it on your UAP-AC-PRO, because the UAP-AC-PRO doesn't list 24V passive support as far as I can see

From the UBNT website:

> "UAP-AC-LITEs with a date code prior of 1634 or board revision before 33 only support 24V passive PoE."

EDIT: that injector you linked is super weird, it lists itself as 802.3af compliant but says it is passive-only so it always supplies 48V without the device needing to request power

I'd avoid it and get a proper active 802.3af injector

Here's a sad story from someone who bought one of those non-compliant 802.3af injectors and fried their hardware

https://www.reddit.com/r/Ubiquiti/comments/o7kjxj/the_upoeaf_doesnt_support_8023af_its_an_passive/

steve98

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#2750651 27-Jul-2021 13:11

OzoneNZ:

Pretty certain that UAP-AC-PRO models are all 48V 802.3af (active) PoE

Earlier UAP-AC-LITE models only came with 24V passive injectors so you should check the box of your UAP-AC-LITE to see if it lists support for 802.3af.

I'd be very careful to confirm that your existing injector from the UAP-AC-LITE is not one of the 24V passive ones before trying to use it on your UAP-AC-PRO, because the UAP-AC-PRO doesn't list 24V passive support as far as I can see

From the UBNT website:

> "UAP-AC-LITEs with a date code prior of 1634 or board revision before 33 only support 24V passive PoE."

EDIT: that injector you linked is super weird, it lists itself as 802.3af compliant but says it is passive-only so it always supplies 48V without the device needing to request power

I'd avoid it and get a proper active 802.3af injector

Here's a sad story from someone who bought one of those non-compliant 802.3af injectors and fried their hardware

https://www.reddit.com/r/Ubiquiti/comments/o7kjxj/the_upoeaf_doesnt_support_8023af_its_an_passive/

OK thanks. Have checked the box for the AC-Lite and it says "Supports Gigabit 24V and 802.3af/A PoE" and says that the injector in the box is "Gigabit PoE Adapter (24V, 0.5A)" --- so do you think it would power the AC-Pro? Sorry, I find this part of it a bit confusing.

sbiddle

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#2750672 27-Jul-2021 13:18

UniFi hardware falls into 4 different categories - products powered by 24V passive POE, products powered by 48V passive PoE, products powered by 24V passive PoE + 48V 802.3af and products powered by 48V passive PoE and 48v 802.3af

The UniFi AC Lite comes with a 24V passive PoE adapter. Depending on the age of the AP this can also be powered by a 802.3af power supply (first year or so of this product was 24V only, subsequent versions support both).

The UniFi AC Pro is a 48V passive PoE / 48V 802.3af compatible device. It cannot be powered by the 24V AC lite power adapter, but will work with the 48V or 802.3af adapter

Without checking that PB Tech part number I can't guarantee that is the correct model (UBNT make multiple 48V adapters, some which will not work) but I'm pretty sure it's the correct one.

OzoneNZ

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#2750675 27-Jul-2021 13:26

I don't blame you, PoE is a fragmented mess and Ubiquiti hasn't done anything to simplify it by releasing non-compliant injectors haha

Sounds like you have a 24V passive PoE injector even though your UAP-AC-LITE supports 802.3af active PoE, so unfortunately I don't think it will work with your UAP-AC-PRO

I think this should do the job nicely but I'll wait for someone else on here to sanity-check my choice:

https://www.pbtech.co.nz/product/NETTPL0150/TP-Link-TL-POE150S-Gigabit-PoE-Injector-8023af--15

For future reference the most common types of PoE hardware you'll find today are:

- 24V passive PoE

- 48V passive PoE

- 802.3af (48V active, up to 15.4 Watts)

- 802.3at (48V active, up to 30 Watts)

Stay away from passive PoE when possible, it's an old spec that has lead to countless people frying their hardware because it constantly supplies power even when not requested by the connected device.

Active PoE requires the connected device to actually negotiate how much power it requires before any is supplied, so it's much safer.