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Emerging Member
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Registered: ‎10-08-2017
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Can I use Nano Switch for non-poe applications?

For some reason the whole POE passthrough thing always trips me up.

 

I need a switch at the end of a 135' run to connect to another 185' run to an outdoor generator.  Reason is, I'm over 300' total but have the ability to put a switch close to half way.  Problem is I'd like to do it without needing power where the switch is located (in a garage).

 

So the Nano Switch is a good fit.  BUT...

 

Can I use the nano switch bringing in 24V from a 16 port POE swtich to power it, but then connect it to a generator that has a standard ethernet port not needing poe?

 

Is this a case where it won't send the voltage unless it negotiate POE connectivity?  I thought that was POE+  does it also apply to 24v passthrough?  I'm always worried that I'm going to fry equipment at the other end when plugging into a poe port.

 

Thanks,

 

Roveer

 

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Re: Can I use Nano Switch for non-poe applications?

[ Edited ]

Unfortunately, the design for this--and the similar F-POE--

doesn't include a PoE defeat switch; there's no way to

turn it off. Oddly enough, I've found places on the circuit

board that seem to imply this was in the original design.

 

I've used a band-aid solution for Gb circuits: a passive

PoE injector, used in reverse. This isolates the dc power

from the target device; it has internal transformers for this.

It only costs under $8, so it's not a big penalty.

 

If you're only using this for 100Mbps circuits, you can

simply eliminate leads 4, 5, 7 and 8 to disconnect power.

This won't work on Gb circuits--which need all 8 leads.   Dave


> HQ in Seacoast region New Hampshire U.S.A.
> Ubiquiti Certified Trainer [UCT] for:
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Re: Can I use Nano Switch for non-poe applications?


@Dave-D wrote:

If you're only using this for 100Mbps circuits, you can

simply eliminate leads 4, 5, 7 and 8 to disconnect power.

This won't work on Gb circuits--which need all 8 leads.   Dave


The generator most likely doesn't need gig so using only the 2 data pairs is a viable consideration.

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Re: Can I use Nano Switch for non-poe applications?

It could be; that's why I provided both choices.  Dave


> HQ in Seacoast region New Hampshire U.S.A.
> Ubiquiti Certified Trainer [UCT] for:
     UBWA [AirMax] / UEWA [UniFi] / UBRSS [routers]
UBNT.NH@gmail.com
Emerging Member
Posts: 61
Registered: ‎10-08-2017
Kudos: 3

Re: Can I use Nano Switch for non-poe applications?


@Dave-D wrote:

I've used a band-aid solution for Gb circuits: a passive

PoE injector, used in reverse. This isolates the dc power

from the target device; it has internal transformers for this.

It only costs under $8, so it's not a big penalty.


Is there any way I can use a ubiquiti POE adapter to achieve the same thing?  Let's say take from the nanoswitch into the red POE port on the injector and then out on the lan port to the generator?  Would that remove the 24v from the wire?  I have a handfull of POE injectors that I will not be using.  It's either that or I'm only going to feed it 100mb on 1,2,3 & 6.

 

Roveer

SuperUser
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Registered: ‎06-23-2009
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Re: Can I use Nano Switch for non-poe applications?

No: don't use an ac mains PoE injector for this.

 

Why agonize over a $6 Gb passive PoE injector?

If you need Gb then use it. If you only need 100Mbps.,

use the stripped-down cable I described.   Dave


> HQ in Seacoast region New Hampshire U.S.A.
> Ubiquiti Certified Trainer [UCT] for:
     UBWA [AirMax] / UEWA [UniFi] / UBRSS [routers]
UBNT.NH@gmail.com