Does anyone have a source for 24 vDC injectors for PoE?
-----
Mike Hammett
Intelligent Computing Solutions
http://www.ics-il.com
----- Original Message -----
From: "Eric Albert" <[EMAIL PROTECTED]>
To: "WISPA General List" <[email protected]>
Sent: Tuesday, November 13, 2007 6:09 PM
Subject: RE: [WISPA] Which UPS to use?
This seems like a good opportunity to lob in a sales pitch of sorts. But I
will disguise it as an engineering discussion to appease the tech crowd. I
will preface my comments by saying I do not know the original application
for which this question was posed.
Most of the gear (there are exceptions) in our business, in the end run on
DC power. Our radios are a good example. The chassis based BS-AU can run
on -48 VDC power supplies and supply the necessary DC voltages to the cards
and ODUs. The process of running a UPS (which in application is a battery
powering an inverter) only to knock down the 120VAC into DC seems overkill.
The process is inefficient, generates heat and can be expensive. This
process is commonly known as the double-conversion method.
Side bar: some UPS units, not all, don't handle power correction. They will
kick on during under/over voltage situations but they do little to correct
for the quality of the power. Over time poor AC power quality will chip away
at the MTBF of everything connected to it. I have also heard that many of
the more popular UPS units have trouble with generators, especially the
generators that have automatic throttles. If the quality of the generated
power is poor it will burn up the MOVs that are in place at the input side
of the UPS. But I digress...
I think the Telcos have had it right for some time. Although how they got
there is another discussion. But in the end DC power affords you some
options. A properly engineered DC power plant will take the brunt of "bad"
power and isolate it from your gear. The rectifiers take the hit so to speak
and the batteries don't care. Any power events such as brownouts, surges or
blackouts don't get telegraphed to the radio equipment. Another point worth
noting is the availability of modular-based rectifiers and battery chargers.
Lots of options. (I have even seen hydrogen fuel cell units in place a major
POPs. Really cool gear.)
One WISP who has employed this design had a long outage that almost drained
the batteries. They pulled a pickup truck with a full tank of gas up to the
site and topped off the DC string. Others have taken the approach of using
wind/solar/hydro/utility.
Also, if you can build a POP on nothing but DC, think of how much energy you
will save just by cutting out the wasted heat that an inverter (or UPS)
creates. If the design calls for a cabinet, chances are you will not back-up
the air conditioner. Where does all that heat go during a long outage? (DC
fans anyone?)
Here is the sales pitch. Alvarion manufactures several options in the DC
genre. We have the aforementioned -48VDC PS for the BS-SH chassis solution.
When you design a system with one radio family (i.e. VL) redundant power
supplies can be implemented at the tower.
And now, for the Pièce de résistance, we have a DC standalone power supply
for VL. It is the OPS-DC. Its input range is 10.5 to 32 VDC and draws less
than 1A at 24VDC. Slightly more draw at 12VDC. The temperature range is -31
to +131F. Why all the hoopla? A DC battery charger with a good deep cycle
battery and the OPS-DC could run a VL sector for... well, a really long
time.
This idea will certainly not work for everyone or for every design. But it
sure is fun to imagine the possibilities. I hope to hear some creative
responses. Thanks for reading.
Eric
Eric Albert
Application Engineer
Alvarion, Inc.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Tom DeReggi
Sent: Tuesday, November 13, 2007 2:34 PM
To: WISPA General List
Subject: Re: [WISPA] Which UPS to use?
Note: the 9606 is 10mbps.
Tom DeReggi
RapidDSL & Wireless, Inc
IntAirNet- Fixed Wireless Broadband
----- Original Message -----
From: Travis Johnson
To: WISPA General List
Sent: Tuesday, November 13, 2007 11:09 AM
Subject: Re: [WISPA] Which UPS to use?
Yes, you can. We have about 50 of them doing just that.
Travis
Microserv
Mark Nash wrote:
I remember now. The 9606 doesn't do e-mail notification. That was
important for me. You can set up e-mail address recipients and assign a
severity to each one of them: Informational, Warning, Critical.
Mark Nash
UnwiredOnline.Net
350 Holly Street
Junction City, OR 97448
http://www.uwol.net
541-998-5555
541-998-5599 fax
----- Original Message -----
From: "Adam Kennedy" <[EMAIL PROTECTED]>
To: "WISPA General List" <[email protected]>
Sent: Tuesday, November 13, 2007 7:09 AM
Subject: Re: [WISPA] Which UPS to use?
Mike Hammett wrote:
> The 17 does environmental monitoring as well.
Um, no it doesn't.
AP9606 - Basic Web/SNMP Management card
http://www.apcc.com/resource/include/techspec_index.cfm?base_sku=AP9606
AP9617 - Advanced Web/SNMP Management (email capability etc.)
http://www.apcc.com/resource/include/techspec_index.cfm?base_sku=AP9617
AP9619 - Advanced Web/SNMP Management with Environmental monitoring
http://www.apcc.com/resource/include/techspec_index.cfm?base_sku=AP9619
----- Original Message ----- From: "Mark Nash" <[EMAIL PROTECTED]>
To: "WISPA General List" <[email protected]>
Sent: Monday, November 12, 2007 7:02 PM
Subject: Re: [WISPA] Which UPS to use?
Gino, how does that differ from the ap9617?
Mark Nash
UnwiredOnline
350 Holly Street
Junction City, OR 97448
http://www.uwol.net
541-998-5555
541-998-5599 fax
----- Original Message ----- From: "Gino Villarini" <[EMAIL PROTECTED]>
To: "WISPA General List" <[email protected]>
Sent: Monday, November 12, 2007 5:01 PM
Subject: RE: [WISPA] Which UPS to use?
$125 for the snmp card?
We are buying the ap9606 for $50
Gino A. Villarini
[EMAIL PROTECTED]
Aeronet Wireless Broadband Corp.
tel 787.273.4143 fax 787.273.4145
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Mark Nash
Sent: Monday, November 12, 2007 8:48 PM
To: WISPA General List
Subject: Re: [WISPA] Which UPS to use?
UPS - $45 on ebay (buy one without batteries)
SNMP card - $125 on ebay
2 batteries & 2 outdoor battery compartments: $150-$175 (more,
depending
on
battery quality). I get mine at Bimart.
misc connectors & wire $20
I had one site up for 36 hours with Trango Tlink, small switch, and
Tranzeo
AP. I thnk that's best-case-scenario.
Mark Nash
UnwiredOnline
350 Holly Street
Junction City, OR 97448
http://www.uwol.net
541-998-5555
541-998-5599 fax
----- Original Message ----- From: "George Rogato"
<[EMAIL PROTECTED]>
To: "WISPA General List" <[email protected]>
Sent: Monday, November 12, 2007 2:32 PM
Subject: Re: [WISPA] Which UPS to use?
Not sure how much I need really. It's the downtime.
This one pop has a trango, a wrap a metro and a cheap switch. Usually
when
it looses power it could be 24 hours or more.
With your set up, how much do you pay including the 2 rv batteries and
how
long have you had for a power outage?
I just ordered one of the cheapo generics for my house to check out.
But
generic usually leaves that feeling of uncertainty that makes me
uneasy.
Mark Nash wrote:
George, are you really needing that much? 3KVA? Or is it the
higher
battery capacity you're wanting?
I buy used APC Smart-UPS SU700NET from ebay, without batteries. Then
I
buy
a couple RV batteries and hook them up (outside the enclosure, of
course).
I put in a AP9617 SNMP device and it gives me a little remote control
w/e-mail notification. Doesn't do everything I want (PDU-ability to
power
off each receptacle individually, watchdog).
On a remote site, it'll give anywhere from 12-24 hours depending on
load
&
whatchya got out there...
Mark Nash
UnwiredOnline.Net
350 Holly Street
Junction City, OR 97448
http://www.uwol.net
541-998-5555
541-998-5599 fax
----- Original Message ----- From: "George Rogato"
<[EMAIL PROTECTED]>
To: "WISPA General List" <[email protected]>
Sent: Monday, November 12, 2007 11:27 AM
Subject: [WISPA] Which UPS to use?
I need to buy a few ups's for some remote pops.
I was looking at APC and the place I buy stuff from had these:
http://www.pacificgeek.com/product.asp?ID=52353&C=216&S=-1
Is this worth buying, or should I go with APC at twice the price?
http://www.apcc.com/resource/include/techspec_index.cfm?base_sku=SUA3000
--
George Rogato
Welcome to WISPA
www.wispa.org
http://signup.wispa.org/
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