Paul,
Duracomm gear is tried and true with nothin fancy about what it does.
I have had these units installed for 10yrs and battery life goes to 7yrs.
We have a few in some extreme conditions as well IE elevator Shaft top
floor
hardly any ventilation there batteries usually go for about 5yrs.
On 09/02/2015 11:29 AM, Paul McCall wrote:
Yep!
*From:*Af [mailto:[email protected]] *On Behalf Of *[email protected]
*Sent:* Wednesday, September 02, 2015 11:47 AM
*To:* [email protected]
*Subject:* Re: [AFMUG] 48v charging systems
Cycling the batteries rather than floating them will cause them to
have a shorter lifespan.
You never know where the surge is coming from or going to. Cat 5,
tower steel, ground, power etc.
*From:*Paul McCall <mailto:[email protected]>
*Sent:*Wednesday, September 2, 2015 9:43 AM
*To:*[email protected] <mailto:[email protected]>
*Subject:*Re: [AFMUG] 48v charging systems
That seems similar to what we have now flow wise, with fuses etc.
Somehow I was thinking that if the charging system could be isolated
from the batteries themselves that a strong surge can’t blow past the
charger and up to our gear.
I see what you are saying… I could run the charger on a timer only,
but the timer could still be a point of vulnerability. I know it
sounds funny, but I have actually been thinking of an RF based
(cellular or digital 2-way service) to remote power cycle or turn
on/off AC to a tower, in the event of pending nasty storms. We watch
the weather pretty close here and have had lots of incidences this season.
*From:*Af [mailto:[email protected]] *On Behalf Of *[email protected]
<mailto:[email protected]>
*Sent:* Wednesday, September 02, 2015 11:00 AM
*To:* [email protected] <mailto:[email protected]>
*Subject:* Re: [AFMUG] 48v charging systems
Well, normally the bus voltage is 55 volts. And the charger/rectifier
is paralleled with the batts and the load.
I like fuses on the charger and on the batts. You want a fuse on the
charger that is equal or slightly larger than the maximum charger
output current.
Fuses on the load appropriate to the load and wiring.
Charger/rectifiers that are designed for float duty like this do not
present any load to the batts when the power is off. No need for
steering diodes or anything like that.
One way to get a high quality charger is a solar charge controller.
Then you can feed them with a cheap and dirty source.
Consider whether you have to tie the + side to ground. I would float
everything if I can, but some radios tie one side to ground so you may
as well try to do common point grounding if that is the case.
The only way I know to get true and total isolation is with a motor –
generator set and still an impulse could be conducted through the
grounded chassis of the device.
*From:*Paul McCall <mailto:[email protected]>
*Sent:*Wednesday, September 2, 2015 7:00 AM
*To:*[email protected] <mailto:[email protected]>
*Subject:*[AFMUG] 48v charging systems
We are new to 48v, but are considering running 48v and fiber up the
tower.
What are the best devices to charge the batteries? Right now, we are
using a 24v system with a common bus bar that allows everything to run
off either batteries or AC to DC charger output. Was thinking
conceptually of somehow isolating that so that everything only ran off
the batteries if that is possible, thinking that might protect us
better from surges, but maybe that isn’t possible.
Hmmmm…
Paul McCall, Pres.
PDMNet / Florida Broadband
658 Old Dixie Highway
Vero Beach, FL 32962
772-564-6800 office
772-473-0352 cell
www.pdmnet.com <http://www.pdmnet.com/>
[email protected] <mailto:[email protected]>
