FWIW, the POE injector itself should be agnostic WRT polarity. The issue boils
down to three things; (1) The polarity of the power supply, (2) The polarity of
the equipment, and (3) whether either 1 or 2 bond their respective returns to
chassis ground.
If both the PS and the equipment isolate logic ground from chassis ground, then
-V and +V are basically a don't care. As soon as one or the other (or both)
bonds logic ground to chassis ground, then you better be paying attention.
I know that many/most Trango radios bond logic ground to chassis ground, and
they are -48V (or +48V return). If all other equipment on site is also -48V,
then you're probably OK. However, as soon as another piece of equipment gets
added to the site, _AND_ it is +48V, then you have a conflict. At this point,
you need to figure out how you're going to keep +48V away from the -48V.
-bp
On Wednesday, December 7, 2016 10:16 AM, Mark Radabaugh <[email protected]>
wrote:
It’s marked -48V on the power connector. I don’t think I would try floating
a ground with it to use +48. If you only have +48 a Meanwell DC/DC converter
to get -48V is a lot less expensive than the POE injector. Of course maybe you
want POE in which case it might justify the cost.
We routinely run these with a 2x22 gauge copper + 2 fiber cable where we use
the copper as the -48V/0V and the fiber for data. We do not connect the
POE/Copper Ethernet port, or the 3rd management port.
Mark Radabaugh
Amplex
22690 Pemberville Rd
Luckey, OH 43443
419-837-5015 x1021419-261-5996 (cell)
[email protected]
On Dec 7, 2016, at 11:09 AM, Faisal Imtiaz <[email protected]> wrote:
Hi Mark,
Just to make sure there this is no confusion in the 'lingo'
820C/IP20c is designed to run on -48v DC (telecom power plant), and the radio
gets powder via the Ethernet cable (POE)
The external POE Injector device is presented as a DC-DC converter..
The question was is this necessary when using +48vdc power source or just a
matter of changing polarity...
Regards.
Faisal Imtiaz
Snappy Internet & Telecom
7266 SW 48 Street
Miami, FL 33155
Tel: 305 663 5518 x 232
Help-desk: (305)663-5518 Option 2 or Email: [email protected]
----- Original Message -----
From: "Mark Radabaugh" <[email protected]>
To: [email protected]
Sent: Wednesday, December 7, 2016 10:56:06 AM
Subject: Re: [AFMUG] WTB IP-20C POE
The answer to the question:
The 820C runs perfectly fine on -48VDC run directly to the radio.
You do not need the POE adapter unless you really want to run them using POE.
I do not explicitly know if they will run on +48VDC - I believe they will but
have not actually tried that.
We have quite a few running on -48VDC from Emerson and Eltek rectifier shelfs.
Mark
On Dec 7, 2016, at 10:20 AM, [email protected] wrote:
yes
-----Original Message----- From: Faisal Imtiaz
Sent: Tuesday, December 6, 2016 5:13 PM
To: [email protected]
Subject: Re: [AFMUG] WTB IP-20C POE
Hi Chuck...
This may be an opportunity to clarify something...
According to the specs Ceragon IP-20c is a -48vdc radio.
Their POE box/adapter, takes 48v dc or 24v dc and powers the radio.
There has not been any clear answer if their Radios will run on regular 48vdc
directly ...
There have been folks who have 'tested' the cambium 820 version of these
plugging directly on the Netonix switches.
In my opinion, these are not 'in-expensive' radios that I would risk installing
in-correctly.
In recommending your injector / surge protector as a solution, my question would
be.
1) can we do -48v dc power via these devices ? it is just a matter of making
sure the polarity of the dc cable is correct ? or is there more to it.
Regards
Faisal Imtiaz
----- Original Message -----
From: "Chuck McCown" <[email protected]>
To: [email protected]
Sent: Tuesday, December 6, 2016 6:08:49 PM
Subject: Re: [AFMUG] WTB IP-20C POE
I am hurt...
http://www.mccowntech.com/800-gige-poe-outdoor-midspan-poe-injector-ethernet-surge-protector/
http://www.mccowntech.com/800-gige-poe-apc-rack-mount-surge-protector-power-inserter/
Sheesh!
-----Original Message-----
From: Faisal Imtiaz
Sent: Tuesday, December 06, 2016 3:55 PM
To: [email protected]
Subject: Re: [AFMUG] WTB IP-20C POE
Some suggestions:-
for the POE injector...
you can try a Cambium Reseller.
you can possibly by them on Ebay (shipping from Israel)
you can try Surplus Wireless Gear folks too.
In regards to the Power Supply, that is a straight forward 48v DC power
supply (Brick).
Regards
Faisal Imtiaz
Snappy Internet & Telecom
7266 SW 48 Street
Miami, FL 33155
Tel: 305 663 5518 x 232
Help-desk: (305)663-5518 Option 2 or Email: [email protected]
----- Original Message -----
From: "Sterling Jacobson" <[email protected]>
To: "[email protected]" <[email protected]>
Sent: Tuesday, December 6, 2016 5:45:19 PM
Subject: [AFMUG] WTB IP-20C POE
Somehow I misplaced my Ceragon POE injector and power supplies during a
cabinet
move.
Anyone happen to have a Ceragon IP-20C compatible POE unit they could sell
me?
I think the power supplies probably aren't that hard to find, but the POE
apparently is.
