Chuck, Interesting info, regarding VPC.
As you proved, there is a logic to minimum range should be designed for. But the question is also, what was designed as the Maximum? Many products have fuses that peak at a specific level, to protect from over voltage damage. For example, WRAP boards that blew the fuse at 21volts, or older WAR2 boards blowing with non-regulated 24v supplies, when as much as 29v overvoltage was sent. If Alvarion is powered at 55v as Gino stated, it would be running near the maximum threshold of your minimum spec for 48v. So what is Alvarion's max, before it blows? It could be a factor of what level of surge/fuse protection the combined POE system on the ground needs, to adequately protect the on tower radios. Tom DeReggi RapidDSL & Wireless, Inc IntAirNet- Fixed Wireless Broadband ----- Original Message ----- From: "Chuck McCown - 3" <[EMAIL PROTECTED]> To: "WISPA General List" <wireless@wispa.org> Sent: Friday, October 10, 2008 8:33 AM Subject: Re: [WISPA] Alvarion VL Rackmount > Yes, the normal float voltage for flooded cell batts is 2.25 VPC. For a > 48 > Volt battery that is 24 cells x 2.25 = 54 volts. Some folks charge at 55 > volts. > Then during discharge, some consider 1.8 VPC to be the lower limit. 24 x > 1. > = 43.2 volts. I personally like 44 volts as the lower limit. So equipment > designed to operate from a -48 volt supply is designed to span those > limits > at a minimum. Most would probably exceed that range by a volt or two on > each end. > > ----- Original Message ----- > From: "Cameron Kilton" <[EMAIL PROTECTED]> > To: "'WISPA General List'" <wireless@wispa.org> > Sent: Friday, October 10, 2008 6:50 AM > Subject: Re: [WISPA] Alvarion VL Rackmount > > >> There must be some sort of tolerance. Units work between 48 and 55v? >> Something to that affect. >> >> -Cameron >> >> -----Original Message----- >> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On >> Behalf Of Gino Villarini >> Sent: Thursday, October 09, 2008 4:08 PM >> To: WISPA General List >> Subject: Re: [WISPA] Alvarion VL Rackmount >> >> Iirc alvarion vl are 55 vdc >> >> Gino >> >> >> -----Original Message----- >> From: Tom DeReggi <[EMAIL PROTECTED]> >> Sent: Thursday, October 09, 2008 3:42 PM >> To: WISPA General List <wireless@wispa.org> >> Subject: Re: [WISPA] Alvarion VL Rackmount >> >> Yes, the first place to start is to determine the Alvarion specs. 1) Max >> >> power or amperage draw from the Alvarion VLs, and 2) min and max Voltage >> >> tolerance. I don;t have that answer for you. But please share it, when >> you >> find out :-) >> >> The general rule is, you can make a combine POE system to serve >> identical >> distances as standalone POE systems. But you still ahve to do the math >> for >> stnadalone POE system. For example, You can take a 48V POE up 500 feet >> easilly, to deliver JUST POWER. But data will never go that high. If >> you >> had to serve height beyond Ethernet POE specs, you'd then need to do the >> >> Power extraction up in a NEMA box on the tower. >> >> Again, we did not do it with Alvarion, but the way we did it was.... >> >> We took standard standalone POE injectors (ones without integrated PS). >> Valemount Injectors that are black, square, one led, and sell for about >> $5-$7. >> This allowed us to have circuit board connecting both Ether jacks for >> reliability. >> These models allowed a wiretie to fit between the PS jack and the CAT5 >> plug, >> so it could be asilly secured and easilly individually untied in the >> field. >> We put one extra one inline for hot spare. >> Now, we were doing 24v, so You need to confirm the injectors that you >> selected allowed voltage level for Alvarion. >> I know the little white half moons, can do 48V no problem. >> If the standard 802.11 pin-out isn;t what Alvarion uses, then compensate >> >> with the pin-out of the Plug crimping on. >> We then laid them side by side mounted flat to a plywood strip. >> We actually just screwed the Strip to the rack, because we cut it to >> reach >> 19" rack. >> It could also be glued to a Nema Box back, with construction plywood >> roof >> glue. >> We cut the height of the strip about 6 inches, so we had 2 inched on top >> and >> bottom to Staple patch cable in place, with it still having room to >> unplug. >> IN one case we used screw in eye hooks, and then just strapped the cable >> to >> the eye hook for strain relief. >> We then took standard two strand wire and soldered the round plugs to >> them >> (the kind that the standard POE required). >> We then took two of those standard screw down DC bus bars (can be >> ordered >> from any electrician or electronic store) with like 8-12 screws on >> thems, >> and labeled them - and +. Then of course screwed down the wires to >> them. >> (Just as easilly we could have soldered the eight wires togeather, so >> all >> the cables were like a 8 cable bundled single unit.) >> We then Used a thicker guage wire, I think it was 16-18 guage and ran >> that >> from the Bud Bar to our dedicated power supply. >> (Many power supply types available). >> >> Whether it works is just doing the math of cable Voltage loss, and how >> much >> amperage the cable can take. See AWG chart attached. >> Also see POE calculater at >> http://www.demarctech.com/techsupport/poecalculate.htm >> Its importnat to remember that the Voltage loss is different based on >> the >> amperage that is occuring at the time, so you don;t want to over power >> voltage to compensate for the loss, to the extent that an inactive radio >> >> would be delviered voltage greater than the radio could accept. >> >> Tom DeReggi >> RapidDSL & Wireless, Inc >> IntAirNet- Fixed Wireless Broadband >> >> >> ----- Original Message ----- >> From: "Cameron Kilton" <[EMAIL PROTECTED]> >> To: "'WISPA General List'" <wireless@wispa.org> >> Sent: Thursday, October 09, 2008 1:18 PM >> Subject: Re: [WISPA] Alvarion VL Rackmount >> >> >>> All of your questions Tom are important and have taken those into >>> consideration. >>> >>> Right now, I just want to figure out if anybody has done it and how. >>> >>> We have made a POE system that puts out 48volt and it works on the >> bench >>> with VL units, but when there is a significant cable run it stops >>> working, I guess the important thing to find out is what is the >> minimum >>> and maximum voltage that can be sent to a Alvarion VL or B radio? >>> >>> -Cameron >>> >>> -----Original Message----- >>> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] >> On >>> Behalf Of Randy Cosby >>> Sent: Thursday, October 09, 2008 1:07 PM >>> To: WISPA General List >>> Subject: Re: [WISPA] Alvarion VL Rackmount >>> >>> I have got to put a plug in for the "SuperRMS". We just installed our >>> second unit. Just a great box for doing DC power control (or AC if >> you >>> want). Pricey, but very flexibile and powerful. Also has >> temperature, >>> voltage measurent, alarm contact monitoring, USB port with camera >>> drivers, alert and relay scripting, linux shell and on and on.... >>> >>> http://www.remotemonitoringsystems.ca/rms2/ >>> >>> >>> >>> Tom DeReggi wrote: >>>> There are three questions that come up... >>>> >>>> 1) Redundancy >>>> 2) minimizing impact of failure >>>> 3) Ability to remote reboot. >>>> >>>> We had chosen to stay with individual AC Adapter POE systems, for the >>> above >>>> reasons. >>>> The individual AC PS adapter plugged into the AC style Digital Logger >>> reboot >>>> device. >>>> If a PS fails, only one radio dies, and quick to replace the one PS >>> for $15. >>>> And if a radio locks up, we can reboot the port via Digital logger. >>>> Whether or not our device is located in the Closet, mid-way on tower, >>> or way >>>> up the tower, its one standard method to remote access the devices, >>> and >>>> power them. >>>> >>>> So to run one cetnral power supply to power all radios.... How will >>> you >>>> remote reboot them? And what will you do if the main Power supply >>> fails? >>>> I'd only recommend doing a shared power supply if it was redundant >>> with a >>>> ready to go spare (two units onsite). As well, you then need to >>> convert to >>>> a DC based reboot device, and put the relays (or it) inline with the >>> power >>>> to the POE. >>>> >>>> Digital logger also makes a DC based model, with screw down panels. >>> This >>>> device could be your method to combine the DC power. However not >>> positive >>>> but this model might be 24V. >>>> http://www.digital-loggers.com/din.html >>>> . >>>> I think Alvarions are 54-56V. Side note some of the old MEtrocom >>> installs >>>> had used 54V powersupply power plants. You might be able to find them >>> used >>>> cheap. I know we had picked up a few. (but didn;t have 54V gear) >>>> >>>> >>>> >>>> Tom DeReggi >>>> RapidDSL & Wireless, Inc >>>> IntAirNet- Fixed Wireless Broadband >>>> >>>> >>>> ----- Original Message ----- >>>> From: "Cameron Kilton" <[EMAIL PROTECTED]> >>>> To: <wireless@wispa.org> >>>> Sent: Thursday, October 09, 2008 8:29 AM >>>> Subject: [WISPA] Alvarion VL Rackmount >>>> >>>> >>>>> I have a bunch of Stand Alone 5.8 VL AU gear, I want to make a 12 >>> port >>>>> rack mount power supply for it. Has anybody tried this? >>>>> >>>>> Thank You, >>>>> Cameron Kilton >>>>> >>>>> >>>>> >>>>> >>>>> >>> >> ------------------------------------------------------------------------ >>> -------- >>>>> WISPA Wants You! Join today! >>>>> http://signup.wispa.org/ >>>>> >>> >> ------------------------------------------------------------------------ >>> -------- >>>>> >>>>> WISPA Wireless List: wireless@wispa.org >>>>> >>>>> Subscribe/Unsubscribe: >>>>> http://lists.wispa.org/mailman/listinfo/wireless >>>>> >>>>> Archives: http://lists.wispa.org/pipermail/wireless/ >>>> >>>> >>>> >>>> >>> >> ------------------------------------------------------------------------ >>> -------- >>>> WISPA Wants You! Join today! >>>> http://signup.wispa.org/ >>>> >>> >> ------------------------------------------------------------------------ >>> -------- >>>> >>>> WISPA Wireless List: wireless@wispa.org >>>> >>>> Subscribe/Unsubscribe: >>>> http://lists.wispa.org/mailman/listinfo/wireless >>>> >>>> Archives: http://lists.wispa.org/pipermail/wireless/ >>> >>> -- >>> Randy Cosby >>> Vice President >>> InfoWest, Inc >>> >>> office: 435-773-6071 >>> >>> >>> >>> >> ------------------------------------------------------------------------ >>> -------- >>> WISPA Wants You! Join today! >>> http://signup.wispa.org/ >>> >> ------------------------------------------------------------------------ >>> -------- >>> >>> WISPA Wireless List: wireless@wispa.org >>> >>> Subscribe/Unsubscribe: >>> http://lists.wispa.org/mailman/listinfo/wireless >>> >>> Archives: http://lists.wispa.org/pipermail/wireless/ >>> >>> >>> >>> >> ------------------------------------------------------------------------ >> -------- >>> WISPA Wants You! Join today! >>> http://signup.wispa.org/ >>> >> ------------------------------------------------------------------------ >> -------- >>> >>> WISPA Wireless List: wireless@wispa.org >>> >>> Subscribe/Unsubscribe: >>> http://lists.wispa.org/mailman/listinfo/wireless >>> >>> Archives: http://lists.wispa.org/pipermail/wireless/ >> >> >> ------------------------------------------------------------------------ >> -------- >> WISPA Wants You! Join today! >> http://signup.wispa.org/ >> ------------------------------------------------------------------------ >> -------- >> >> WISPA Wireless List: wireless@wispa.org >> >> Subscribe/Unsubscribe: >> http://lists.wispa.org/mailman/listinfo/wireless >> >> Archives: http://lists.wispa.org/pipermail/wireless/ >> >> >> >> -------------------------------------------------------------------------------- >> WISPA Wants You! Join today! >> http://signup.wispa.org/ >> -------------------------------------------------------------------------------- >> >> WISPA Wireless List: wireless@wispa.org >> >> Subscribe/Unsubscribe: >> http://lists.wispa.org/mailman/listinfo/wireless >> >> Archives: http://lists.wispa.org/pipermail/wireless/ >> > > > > -------------------------------------------------------------------------------- > WISPA Wants You! Join today! > http://signup.wispa.org/ > -------------------------------------------------------------------------------- > > WISPA Wireless List: wireless@wispa.org > > Subscribe/Unsubscribe: > http://lists.wispa.org/mailman/listinfo/wireless > > Archives: http://lists.wispa.org/pipermail/wireless/ -------------------------------------------------------------------------------- WISPA Wants You! Join today! http://signup.wispa.org/ -------------------------------------------------------------------------------- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
