This is why I gave up on the BCM48 and just started using the BCMU360
instead. The regular BCMs seem to have NO charging current limit. Either
that or something in them breaks and the results are the same. I cooked
a TSP360-148. The one I mentioned a few months ago that screeches on
startup. The thing was pushing over 10 amps on the output for 30-40
minutes trying to charge a string I had sitting for a while. I found out
just after that one of the batteries was shot. So I'm not sure if that's
what screwed up the BCM. This was just sitting on the bench plugged into
a 20A recept in the wall. The breaker didn't trip. There's no way in
hell I'm putting a regular BCM in the field.
I've said this several times. The BCMU360 is rated for 240W continuous
and I don't typically load it up with more than ~220W. I use a Mean Well
SDR-240-48 instead of a TSP360. It's much cheaper, especially after
nuking that first one.
On 5/28/2017 12:33 PM, Chuck McCown wrote:
A 48 volt battery discharged down to 42 volts will be a very very
heavy load for whatever is attempting to charge it.
A TSP 600-148 will only make 12.5 amps max.
Your battery could easily want 25 or 50 amps for the first 10
seconds. It will taper off to zero as it comes up to charge, but the
more dead they are, the more they appear to be a dead short to the
charger.
You have probably never tried to start this system with stoned batts.
What is the amp rating of the battery breaker?
And the AC side will have a pretty high inrush current as well. Is
your AC breaker greater than the power supply inrush current. TSP 600
recommends a 25 amp circuit breaker on 120 VAC.
*From:* Josh Baird
*Sent:* Sunday, May 28, 2017 10:19 AM
*To:* [email protected]
*Subject:* [AFMUG] Traco TSP+BCM Question
I have a site with a TSP+BCM 48V combo. Last night, something caused
the AC breaker to trip, putting the site on battery. We didn't see
the alert until about 12 hours later. At this point, the batteries
were down to ~42V. When our guy arrived on site, he reset the AC
breaker, and AC power was restored. Immediately, the battery breaker
(breaker between positive side of the batteries and the BCM) tripped.
Now, each time that we reset the battery breaker, it causes the AC
breaker to immediately trip. At this point, the site is up on AC with
no battery. Any ideas what would be causing this? Do you think the
batteries are causing the BCM to draw too much current? Could one (or
more) of the batteries be dead/bad? The site *did* run successfully
on battery for nearly 12 hours.
Josh
