That makes a lot more sense... I (and Paul too, I assume) must be reading the spec sheet wrong. I thought buffer mode was referring to when it was running on battery (I assumed that because of something else I read further down the spec sheet), but it must mean something else if it actually does put out 48.0v.
Output voltage / current – Normal Mode 24 VDC mode: Vin – (0.4 - 0.8V); 15 A max. 48 VDC mode: Vin – (0.4 - 0.7V); 7.5 A max. – Buffer Mode 24 VDC mode: 22.2 – 22.9 VDC; 10 A (15 A in boost mode for 10min) 48 VDC mode: 44.6 – 45.3 VDC; 5 A (7.5 A in boost mode for 3min) On Tue, Jan 30, 2018 at 2:27 PM, George Skorup <george.sko...@cbcast.com> wrote: > 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> wrote: > >> Yet, the BCM-148 says adjustable Output up to 54v. Unless you are on >> battery. Silly >> >> >> >> *From:* Af [mailto:af-boun...@afmug.com] *On Behalf Of *Paul McCall >> *Sent:* Tuesday, January 30, 2018 1:35 PM >> >> *To:* 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 <af-boun...@afmug.com>] *On >> Behalf Of *Adam Moffett >> *Sent:* Tuesday, January 30, 2018 1:25 PM >> *To:* 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> >> >> To: "af@afmug.com" <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 <%28772%29%20564-6800> >> >> pa...@pdmnet.net >> >> www.pdmnet.com >> >> www.floridabroadband.com >> >> >> >> >> >> > >
