The 450i and 450m don't really care about polarity. That's one of the reasons that the cambium sync products we sell work with either voltage. The older radios expected +24v with the negative side grounded.
Other radios can be hard to track down. I can confirm that many nowadays use an isolated supply inside so that they don't care if one of the rails are grounded as long as you respect the voltage and polarity into the radio. But others are very much incompatible with either positive or negative ground systems. On Sat, Nov 24, 2018, 10:11 AM Ken Hohhof <[email protected] wrote: > Some WISP equipment like Packetflux started with +24V and extended the > voltage range so now it can be powered via +48/56V. > > > > It’s a little difficult to pin down some radios, it seems like most > 802.3af equipment is actually floating and as long as you observe polarity, > either side of the power supply can be grounded. Documentation usually > doesn’t say. Also some Mikrotik equipment may say -48V in the spec sheet > but the terminals are just labeled + and – and seems to be floating just > like 802.3af. Cambium/Ceragon has a DC powered POE that seems happy with > +24, -48 or +48 input. My belief has always been that Cambium radios like > 450i and 450m want +48V POE but maybe they don’t care. The Cambium POE > brick actually has a 2 pin AC power cord and no ground terminal, implying > that the power source can be floating. I wish manufacturers weren’t so > vague about this. > > > > *From:* AF <[email protected]> *On Behalf Of *Chuck McCown > *Sent:* Saturday, November 24, 2018 9:41 AM > *To:* AnimalFarm Microwave Users Group <[email protected]> > *Subject:* Re: [AFMUG] 48v Power Supply Switches > > > > I guess my experience is the reverse. Having spent 40 years in telecom, > seems that almost everything rack mounted is –48 if you want DC power. I > don’t recall ever finding +48 rack mounted telecom equipment. > > > > *From:* Ken Hohhof > > *Sent:* Saturday, November 24, 2018 7:43 AM > > *To:* 'AnimalFarm Microwave Users Group' > > *Subject:* Re: [AFMUG] 48v Power Supply Switches > > > > I have one site with an Eltek/Valere system and it does its job quite > nicely, my question for you: how do you deal with the Eltek Systems mostly > being designed for -48 yet a lot of the equipment ISPs use wants +48? My > one Eltek site has an old Purewave WiMax basestation that I am about to > decommission but I will need +48 and I don’t want to put in a DC-DC > converter if nothing will be running off the -48. > > > > *From:* AF <[email protected]> *On Behalf Of *Chuck McCown > *Sent:* Saturday, November 24, 2018 8:13 AM > *To:* AnimalFarm Microwave Users Group <[email protected]> > *Subject:* Re: [AFMUG] 48v Power Supply Switches > > > > +1 > > Sent from my iPhone > > > On Nov 24, 2018, at 3:13 AM, Gino A. Villarini <[email protected]> wrote: > > We go direct to Eltek/valere -48 system. It has redundant rectifiers, > web/snmp and LVD > > > > *Gino* *Villarini * > Founder/President > @gvillarini > t: 787.273.4143 > m: > > [image: Image removed by sender. aeronet-logo] <http://www.aeronetpr.com/> > > [image: Image removed by sender. inc500] > <https://www.inc.com/profile/aeronet> > > [image: Image removed by sender. fb-logo] > <https://www.facebook.com/aeronetpr/> > > [image: Image removed by sender. insta-logo] > <https://www.instagram.com/aeronetpr/?hl=en> > > [image: Image removed by sender. in-logo] > <https://www.linkedin.com/company/aeronet-broadband-corp> > > [image: Image removed by sender. tw-logo] > <https://twitter.com/AeroNetPR?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Eauthor> > > > [image: Image removed by sender. yt-logo] > <https://www.youtube.com/channel/UCr2Q9WBrAYVm3Fn970Jd6VA> > > www.aeronetpr.com | Metro Office Park #18 Suite 304 Guaynabo, PR 00968 > > *From: *AF <[email protected]> on behalf of Alex Davidson < > [email protected]> > *Reply-To: *AnimalFarm Microwave Users Group <[email protected]> > *Date: *Friday, November 23, 2018 at 11:13 AM > *To: *"[email protected]" <[email protected]> > *Subject: *[AFMUG] 48v Power Supply Switches > > > > Hey guys, we are stepping up to some 48v equipment on a tower and in > looking into power supply switches. This seemed to be something that would > work for us (Mean Well SE-1000-48). Any thoughts or pros and cons that yall > have found with this unit. Any units of similarity that might work well in > place of this one. Thanks > > > > > > > > -- > AF mailing list > [email protected] > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > > ------------------------------ > > -- > AF mailing list > [email protected] > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > -- > AF mailing list > [email protected] > http://af.afmug.com/mailman/listinfo/af_af.afmug.com >
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