Maximum POE Distance

[rubber_otter]

inb4 100m you idiot. everyone knows that.

I need to power up a Mikrotik over 160m. No data will be running over that cable. Only DC power. Will a 24v POE power up the unit?

 

[$m@Rt@$$]

inb4 100m you idiot. everyone knows that.

I need to power up a Mikrotik over 160m. No data will be running over that cable. Only DC power. Will a 24v POE power up the unit?

100m is your upper limit to avoid unstable network connections. Since you are only powering I suppose you'll be fine. Just keep in mind over that distance you'll lose some volts. Does the receiver have a specified working volt range?

 

[The_Ogre]

PoE usually can accommodate anything up to 48v.

With attenuation being a factor I'd say you should still be able to make it.

 

[yogidabear]

24V PoE over 160m might make it as the tolerance on most of the Mikrotik is 10V minimum. Like the one chap said network transmission would be bad but just voltage should make it if you use the right cable.

Never use CCA for PoE (or any application IMHO)!!! Not all copper cable is created equal as you get 24AWG but in metric they take a chance with 0.45, 0.49 and the real deal 0.51mm cross sectional.

 

[bdt]

Two possible ways around this:

- start with a PoE.at injector (yes, I'm fully aware that Mikrotik are the OTHER clowns that screw with the standard and run at 24Vdc); the point being to minimise power loss at (relatively) extreme distance. Feed that 48V PoE signal into a RouterBoard 48 to 24V Gigabit PoE converter and you should be golden.
- check with Miro if they still carry the Veracity Longspan PoE extender ...which may no longer be necessary as they now apparently have Vivotek PoE extender action, good for up to 300m and indoor and outdoor variants too! (But you'll still want to step down to 24V at the far end)

 

[yogidabear]

So you have passive PoE, 802.3af and 802.3at

Sure everybody knows passive is the clown but what the OP asked is if it would work and yes if he uses the right UTP cable it will.

 

[bdt]

The danger inherent in "passive' PoE is that it actively puts DC voltage on the wires (which you had BETTER had wired correctly (because smoke genie)) that just sits there, always waiting to bite. Contrast with using actual the 802.3 spec where you get the inherent safety of the sensing protocol so that if the wrong thing happens on the far end you are far less likely to have exciting smoke genie things happening.

Sure you pay a bit more in the short term for the kit but, IMO, it is the better/right way to do it.

 

[rubber_otter]

Thanks guys. I came right using a 48v power supply on the one end, and a 24v regulator on the other where the board is. Works like a charm.