Power a unifi ap ac lr with ws-8-160-ac

[joewifi]

Hi,
Would the ws-8-160-ac be appropriate for powering a unifi apc ac lr?

The specs for the switch say:
24V PoE Ports
Pins 4,5 (+)
Pins 7,8 (-).75A


The specs for the AP say:
passive poe 4,5+ 7,8-
24v .5a

Specifically the switch says .75A, but the AP says just .5A. Is that difference going to be ok?

Is powering the port as simple as just changing the port screen config power drop down to 24v?

Thanks!

[Julian]

so if you think in terms of equating water with electricity, which works pretty well at this level:

Voltage is the pressure in the system:

The higher the pressure(voltage) the faster the water will pour out(current, or amperage) of any holes (resistance)

or in mathematical terms: Current is equal to voltage divided by resistance, commonly known as Ohm's law.

Since voltage is set at 24V, and maximum current draw is .5A, that leaves you with a minimum input impedance (or resistance) of 48 ohms..

Long lecture short, yes, the amperage available on the port is .75A, and the unifi only draws .5A, so you're within specifications.

And yes, it really is that simple. you only need to change the drop-down box to 24v, our switch takes care of the rest. If you have any conditions on your cable that will cause damage, the switch will politely decline to power the port until they're corrected.

[sirhc]

Maybe look over the forum for posts that would help you:
viewtopic.php?f=6&t=1178
viewtopic.php?f=6&t=1215

As Julian said, if you plug in the cable BEFORE you apply POE power the switch will check for dead short cables before applying the POE option.

NEVER use 24VH or 48VH unless you KNOW the device will accept power on all 4 pair or it will fry the device and switch.

24VH will always FRY airMAX and UniFi devices.

[joewifi]

so if you think in terms of equating water with electricity, which works pretty well at this level:

Voltage is the pressure in the system:

The higher the pressure(voltage) the faster the water will pour out(current, or amperage) of any holes (resistance)

or in mathematical terms: Current is equal to voltage divided by resistance, commonly known as Ohm's law.

Since voltage is set at 24V, and maximum current draw is .5A, that leaves you with a minimum input impedance (or resistance) of 48 ohms..

Long lecture short, yes, the amperage available on the port is .75A, and the unifi only draws .5A, so you're within specifications.

And yes, it really is that simple. you only need to change the drop-down box to 24v, our switch takes care of the rest. If you have any conditions on your cable that will cause damage, the switch will politely decline to power the port until they're corrected.

Thanks much. That makes perfect sense. I am testing the cables prior to applying power. I've read most of the getting started docs on the website too.

Thanks for all the help!

[sirhc]

If you leave POE SMART ON then when you turn POE on for a port the switch Auto Checks the cable before applying POE power.

After you turn POE ON for a port go look in the Switch Log and you will see the process as it is preformed each time you turn POE on for a port.

[joewifi]

Maybe look over the forum for posts that would help you:
http://forum.netonix.com/viewtopic.php?f=6&t=1178
http://forum.netonix.com/viewtopic.php?f=6&t=1215

As Julian said, if you plug in the cable BEFORE you apply POE power the switch will check for dead short cables before applying the POE option.

NEVER use 24VH or 48VH unless you KNOW the device will accept power on all 4 pair or it will fry the device and switch.

24VH will always from airMAX and UniFi devices.

Thanks.
I appreciate the quick tech support. I actually have already purchased the 8, 12, and 24 port models.. to power an 18 wireless access points install at a large building.

Did you say that 24vh will always work or will always not work for the unifi ac lr access points? Your sentence was missing a word.

Also we purchased 3 of the unifi MESH pro ac outdoor. Will those work with the switches too? What voltage?

Lastly, I really like the cable test function on the switch, but I noticed it doesn't work on cables over 100'. Also I get weird and various results when a unifi ac lr ap is plugged in. No cross shorts though, which I know to avoid. So we will just be testing it with a normal cable tester prior to use.

[sirhc]

NEVER use 24VH or 48VH unless you KNOW the device will accept power on all 4 pair or it will fry the device and switch.

24VH will always FRY airMAX and UniFi devices.

Maybe look over the forum for posts that would help you:
viewtopic.php?f=6&t=1178
viewtopic.php?f=6&t=1215

Also do NOT select 24VH to power a 24V device, it will fry the device and the port.

24VH supplies power on all 4 pair which is needed for long cable runs (over 200 feet) on airFIBER X units but will damage normal 24V Rockets, Nanostations, and similar devices.

48VH supplies power on all 4 pair which is needed to power airFIBER 24 and airFIBER 5 units but will damage devices that only want power on pairs 3 & 4 such as Titanium Rockets or IP Phones and camera.

48VH is also used if powering a WS-6-MIN switch, MIMOSA B5, B5C, and other high power devices from many manufacturers. Always take time to verify a device polarity pin out and voltage requirements before using 48VH.

[lligetfa]

Some 802.3af/at kit can tolerate 48VH. I have tested a couple of different UAPs on port2 of the MINI. There has been a few reports of new UAP-AC-LR units starting to ship with af/at support. The usual caveat applies so always make sure you have one that is not limited to just 24V passive PoE.

[joewifi]

:) Thanks. I will never risk using anything but 24v on these. I am not into experimentation or disaster. Thanks!
By the way, I really, really like these switches. Very intuitive, very fast to configure, so clean. Much easier than working with other switches. Thanks for a good product from what I can tell so far.