Do you already have the fiber? If not, you should consider a hybrid cable that has a few strands of fiber and 2-conductor 12/14AWG for powering the radios? Best-Tronics is a good vendor for this cable.
On Tue, Dec 1, 2015 at 4:11 PM, Craig Baird <cr...@xpressweb.com> wrote: > We've got some Cambium PTP820S radios going up shortly. We will be > running fiber to the radios, so we're debating on POE vs. DC up the tower > for powering them. We have been told by the tower owner that we need to > adhere to R56 for lightning protection. > > Our initial thought was that we would just run POE since we already have > the cable, and it would give us an out-of-band management port. But, > according to the Cambium installation manual (and I think R56 specifies > this too), it says that if we're running POE, we're supposed to bond the > cable shield to the tower every 50 meters. I assume that means at the top > and bottom since our cable runs are all less than 50 meters. In addition, > the manual says that we should use Ethernet surge suppressors. We're > thinking "what a pain in the butt". On the other hand, the Cambium manual > does not address grounding for DC cable in any way other than saying that > the radio has DC (and Ethernet) surge protection built in. > > So the DC option is looking pretty attractive compared to the hoops we'll > need jump through for ethernet. I'm wondering if there's something we're > missing that the Cambium manual doesn't address. I figured just to be > safe, we would go ahead and put DC surge suppressors at the top and bottom > of the DC cable. Is there anything else needed for R56 adherence in this > situation? > > Craig > > >
