WS-6-MINI Power Options

[nriedman]

Sorry for the newbie question, I just wanted to clarify a few things before I continue on. I am using a combination of UBNT Toughswitches and MINI's at the moment. I read on the MINI page to power these 'ONLY' with the airfiber poe injectors, however, I have a wireless link coming into a toughswitch, then through port 8 (48V) to power the MINI to extend ethernet connectivity to some 48V cameras. I realize this is different than using a specific injector, but it has been running a couple weeks like this. Can you tell me if this is a problem and the proper way to daisy chain these units as I have plans to do more of this in the near future.

I plan to eventually replace all the tough switches with 12's, 8's, and mini's to run cameras around a municipal park, just wanted to get the proper power layout.

[lligetfa]

They really should not be PoE powered over only 2 pair but rather over all 4 pairs to ensure the current going through the ethernet transformer does not exceed what they are rated for. A PoE brick such as the AF5/AF24 is a popular way to power them. Of course they are designed to be powered from a Netonix WISP switch 48VH port or through the barrel connector.

[sirhc]

As Les states it is not a good idea to power a MINI with a ToughSwitch as it only supplies power on 2 pair but a ToughSwitch can not supply enough power to damage a MINI as the Polyfuses in the ToughSwitch (.5A in older models) will trip before too much current can damage the Ethernet Transformer in the MINI.

Basically I am saying the MINI is Tougher than the ToughSwitch so no worries.

HOWEVER you can run into the problem of not supplying enough power to properly power the MINI and the device at the other end which will be easy to identify as the device will reboot but if it has been fine then your good.

The nice thing about our switches is they tell you how much power you're using so look at the Heads Up display on the MINI UI and see if the total power consumption is less than 24W (.5A @ 48V) and if it is then your OK, if it is higher than 24W then you are running the risk of the Polyfuse in the TS8 tripping and or devices plugged into the MINI rebooting.

Another thing to look at is the Voltage in that the MINI is reporting and make sure it is close to 48V.

[lligetfa]

...a ToughSwitch can not supply enough power to damage a MINI as the Polyfuses in the ToughSwitch (.5A in older models) will trip before too much current can damage the Ethernet Transformer in the MINI...

Ja, I was speaking in general terms using a generic passive PoE injector.

The MINI is TOUGH

[sirhc]

Yea that is sound advice with POE adapters, one should NOT use a standard 48V POE adapter that does not power on all 4 pair but if the POE adapter is only .5A it too "should" not be able to damage the MINI but I would NOT do it and other people should not do it.

[nriedman]

Great information! The display shows 9W utilization so I assumed that 30W would of been around the maximum (@ .7A on the TS). It also shows an input of 43.6V on the board. Once I replace them with the WS-8 models, I'll be sure to use the 48VH ports to daisy chain the mini's down the line.

[Dawizman]

Can this switch show input voltage via SNMP? Also, is it a bad idea to run these direct off of a 48V battery bank?

[lligetfa]

Depending on the charge controller, a 48V system could see spikes up to 60V during battery conditioning which would be too much for the MINI.

[sirhc]

Yea 60V is the UPPER limit but whatever the input voltage is that is the voltage it passes out as the 48V POE.

It will run on 37V fine and output 24V POE but the 48V would then be 37V.

Yes SNMP will provide voltages.

[te31]

Is the Ubiquity POE-50-60W the only 48VH PoE on the market?