The BCMU360 is definitely 12VDC on the battery side. It uses an internal
DC-DC converter. I'm using several. At 24, it puts out 24.0. And at 48,
it puts out 48.0. Disconnect the power supply from the BCMU and make
sure it's putting out 48.0. The transfer relay in the BCMU runs the load
direct from the supply and switches to battery (and DC-DC) when it
senses low input voltage. It puts out regulated 48 when on battery. But
when the battery gets low, the voltage will sag. I think it's only about
80% efficient below 12.8VDC or so.
The pot on the BCMU is to adjust the battery float voltage. It should be
set to 13.6 or 13.8 from the factory. The trick there is that if the
battery is disconnected, it doesn't put out any voltage. I usually
connect a new battery and let it sit running over night. Then put a
meter on it the next day to see where it's at and adjust a bit if
needed. You'll also want to do this at room temp with the remote probe
disconnected.
The BCMU does have LVD. IIRC, the BATT-OK contact will open at 44-45VDC
to give you an early warning. I believe the LVD cutoff is about 42VDC
(which means the batt will be at 10.5, or 1.75 volts per cell which is a
good limit for a stand-by UPS).
If you're getting 44 volts, as I said, check that the voltage adjust pot
on the supply is set correctly with no load. Or you have too much load
on it. I'm looking at a SiteMonitor right now and it shows 47.6. The 5ch
PDU reports Vin = 480. TSP180-148 + BCMU360. Using about 100W at that
site. I've got 200-ish foot runs and the radios all run fine.
On 1/30/2018 12:49 PM, Mathew Howard wrote:
If I'm looking at the same thing, that one has a built in AC/DC power
supply... it's just adjusting the output voltage of the power supply,
and there's no DC-DC converter involved, so it makes sense to just run
on battery voltage (as far as I can tell it needs 24v or 48v batteries).
On Tue, Jan 30, 2018 at 12:36 PM, Paul McCall <pa...@pdmnet.net
<mailto:pa...@pdmnet.net>> wrote:
Yet, the BCM-148 says adjustable Output up to 54v. Unless you are
on battery. Silly
*From:* Af [mailto:af-boun...@afmug.com
<mailto:af-boun...@afmug.com>] *On Behalf Of *Paul McCall
*Sent:* Tuesday, January 30, 2018 1:35 PM
*To:* af@afmug.com <mailto:af@afmug.com>
*Subject:* Re: [AFMUG] Traco BCM
Actually, the BCMU is the model that takes 12v in and upconverts
it to 48V. It charges the battery array (in parallel) to about
13v per batter. So, why in the world they would design a device
that would upconvert that to anything less than 48v (without load)
is just silly. We have UBNT EP-S16s that will not turn on radios
plugged in, if it gets anything less than 45.5 to 46 volts.
But, even on the BCM-148, (where you run 48v in series, it seems
to have the same design) 45v max output when on battery.
Pretty bizzare
*From:* Af [mailto:af-boun...@afmug.com] *On Behalf Of *Adam Moffett
*Sent:* Tuesday, January 30, 2018 1:25 PM
*To:* af@afmug.com <mailto:af@afmug.com>
*Subject:* Re: [AFMUG] Traco BCM
When running on battery, the load gets battery voltage. The load
being on battery (or charger) voltage seems to be the normal
behavior for these types of systems, so you'd have to really hunt
for something that does it differently.
You can hunt for something with a regulated output, or add a DC-DC
converter inline.
I haven't yet encountered a 48V device that didn't accept the
whole range from "batteries nearly dead" to "bulk charging", so
I'm wondering what that device is that needs >46v.
.....and I'm not a Traco lover. I'm kind of disappointed with it
actually. We must have bought 40 of those kits about 3 years ago,
and we now have 3 faulty BCM modules....they work except they no
longer charge batteries. I also received a whole box of them
where the sticker indicating which pin does what on the BCM was
100% backwards. By following the sticker rather than the manual I
ended up with the temperature sensor (thermistor) connected to the
reset switch. Didn't break anything, but they units won't turn on
that way.
At the time I needed something 48V at a higher wattage than
Meanwell's 48V options, and Traco was suggested. I don't think
I'd go there again.
------ Original Message ------
From: "Paul McCall" <pa...@pdmnet.net <mailto:pa...@pdmnet.net>>
To: "af@afmug.com <mailto:af@afmug.com>" <af@afmug.com
<mailto:af@afmug.com>>
Sent: 1/30/2018 12:59:12 PM
Subject: [AFMUG] Traco BCM
Am I missing something or are the Traco BCM series not very
usable in the real world?
Meaning, the BCMU360 can only put out 45v (for a couple
minutes, then 44v and change), when running on the battery.
Not very usable with some gear that requires about 46v to work
properly. Add in voltage drop on a long run and no-go.
I thought maybe the straight BCM 48v series would be better,
but they appear to have the same spec.
I have to think I am missing something or who the heck would
they sell these to? The industry standard is 48v (54v with
float) so, outputting 44v sustained seems dumb.
Or is me 😊
Enlighten me please, you Traco lovers
Paul McCall, President
PDMNet, Inc. / Florida Broadband, Inc.
658 Old Dixie Highway
<https://maps.google.com/?q=658+Old+Dixie+Highway%0D+Vero+Beach,+FL+32962%0D+772&entry=gmail&source=g>
Vero Beach, FL 32962
<https://maps.google.com/?q=658+Old+Dixie+Highway%0D+Vero+Beach,+FL+32962%0D+772&entry=gmail&source=g>
772-564-6800 <tel:%28772%29%20564-6800>
pa...@pdmnet.net <mailto:pa...@pdmnet.net>
www.pdmnet.com <http://www.pdmnet.com>
www.floridabroadband.com <http://www.floridabroadband.com>
