Well, I had no idea you made these. Thanks! On Tue, Dec 1, 2015 at 4:43 PM, Chuck McCown <ch...@wbmfg.com> wrote:
> I am kinda partial to this one: > > http://www.mccowntech.com/dc-power-line-apc-rack-surge-suppressor-protector/ > > *From:* Josh Baird <joshba...@gmail.com> > *Sent:* Tuesday, December 01, 2015 2:33 PM > *To:* af@afmug.com > *Subject:* Re: [AFMUG] POE vs DC and surge supression > > Not to go too far off track here, but what DC surge protectors have you > used? I priced ones from Calix and they were sort of pricey (>100 each). > > Josh > > On Tue, Dec 1, 2015 at 4:29 PM, Ken Hohhof <af...@kwisp.com> wrote: > >> I can't speak to R56, but the only experience I have with 48V direct DC >> power is with a WiMAX basestation that the manufacturer claimed the field >> failures were reduced to almost zero when they started recommending a DC >> surge protector at the basestation. My personal view is the one by the BS >> or AP (and it should be right next to it) is more important than one on the >> ground. In our case, if a surge tried to blow out our rectifiers and >> battery, it would probably just pop a fuse. Even so, replacing some 48V DC >> equipment on the ground is no big deal compared to replacing an expensive >> basestation up on a tower. >> >> >> -----Original Message----- From: Craig Baird >> Sent: Tuesday, December 01, 2015 3:11 PM >> To: af@afmug.com >> Subject: [AFMUG] POE vs DC and surge supression >> >> >> 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 >> >> >> >> >
