So, is FirstNet going to get finished or is is toast?
From: Lewis Bergman
Sent: Sunday, March 06, 2016 8:31 AM
To: af@afmug.com
Subject: Re: [AFMUG] Eltek Rectifier Huh?
DHS grant money has all but dried up. Most of the money, sadly, was wasted
because everyone wanted to control their little piece rather than pooling the
money to make more efficient use with more complete coverage. The money was
doled out to states to figure out how to spend it. Some did a pretty good job.
Some, Like Texas, handed it out to regional entities, and many of those just
divided up by the number of counties and let them spend it how they wanted.
Most of the money was wasted, coverage duplicated. Now grants are low dollar
left overs. A first class FirstNet type of system could have been built with
what they spent but it most just got blown.
Don't get me wrong, I made a bunch of money off of it but we argued for a more
centralized and consolidated and engineered approach but there were to many
egos involved.
On Sat, Mar 5, 2016 at 3:19 PM Eric Kuhnke <eric.kuh...@gmail.com> wrote:
If an off grid solar site is THAT critical to the level of importance it
needs six nines of electrical feed uptime, average over a year, in my opinion
it should be built as a dual A + B side separated, pair of identical solar
panel + battery + charge systems, feeding all DC equipment that has dual -48
inputs (part102 radios, routers).
Costly yes. The sort of thing you can build with DHS money grants for local
public safety radio systems.
On Mar 5, 2016 8:24 AM, "Chuck McCown" <ch...@wbmfg.com> wrote:
First central office I worked in had a huge- huge- huge- selenium rectifier
stack. Plates about 1 foot square. It was in series with the battery. The
battery also had 25 cells. The selenium rectifier would put in about a two
volt drop under load.
When the power was out, the flooded cells would do their thing and when
they got down to about 44 volts, a large contactor would short out the selenium
rectifier and then the office had 46 volts for a few more hours. Other C.O.s
had a special battery called a CEMF cell or counter electromotive force cell,
that did the same thing as the selenium rectifier.
Might be worth considering this idea again in mission critical
applications. Perhaps solar off grid sites with no battery backup.
From: Jason McKemie
Sent: Saturday, March 05, 2016 1:35 AM
To: af@afmug.com
Subject: Re: [AFMUG] Eltek Rectifier Huh?
I had an Emerson cabinet with pre-installed Loraine rectifier setup that
had a LVD. I replaced it with an Eltek unit though, never used the LVD.
On Friday, March 4, 2016, Eric Kuhnke <eric.kuh...@gmail.com> wrote:
I've never seen a low voltage disconnect on telecom rectifier + float
battery setups. It's assumed that for a backbone ISP POP that you will have an
auto start generator.
Or that you would rather drain your batteries all the way to dead,
damaging them, but keeping the equipment online as long as possible (customer
SLAs and hoping the grid power restores itself before the battery string is
toast).
On Mar 4, 2016 2:19 PM, "Gino Villarini"
<javascript:_e(%7B%7D,'cvml','ginovi...@gmail.com');> wrote:
thats weird, it leaves no space for lvd
Sent from Outlook Mobile
On Fri, Mar 4, 2016 at 2:16 PM -0800,
<javascript:_e(%7B%7D,'cvml','ch...@wbmfg.com');> wrote:
Frequently the rectifier and batts both go to the bus bar in the fuse
or circuit breaker panel.
Some folks feed both the rectifier and batts through a circuit
breaker. If you do that you need to make sure the breaker can handle the max
output of the rectifer or more. When there has been an extended power outage
the batts will max out the rectifier current.
From: Scott Vander Dussen
Sent: Friday, March 4, 2016 1:26 PM
To: javascript:_e(%7B%7D,'cvml','af@afmug.com');
Subject: [AFMUG] Eltek Rectifier Huh?
Trying to figure these things out! I purchased and built an Eltek
rectifier product using these products:
CG1S-AUN-VC COMPACT POWER SHELF / REAR WIRE 200AMP MAX 48V UNIVERSAL
OUTPUT POLARITY
BC2000-A01-10VC 48V, SYSTEM CONTROLLER W/ ETHERNET, NEXTGENERATION,
W/ CLEI
V0750A-VC RECTIFIER, 840W, 53.5V, 15A, FAN COOLED (BOTTOM TO TOP)
-INPUT: 90-264VAC
It seems like this just takes AC power and gives me 48v DC out. I
was expecting it would also attach to a battery array and provide charging of
those batteries plus use their power source if grid power was lost. Am I
totally wrong on that? I don’t see any method of connecting batteries to this
power shelf :/
Noob out,
Scott
