A Hall effect sensor would be the gold standard for a non-intrusive way
to sense current. I looked at cobbling together something on my own, but
it was more complicated than I anticipated.
bp
<part15sbs{at}gmail{dot}com>
On 6/16/2017 11:01 AM, George Skorup wrote:
All we've ever bought are the 10A version. They read accurate enough
to see when a 1/2 or 1A DC-UPS is charging as well as 3-7A the other
direction when the load is running on battery. Typical 24 and 48VDC
systems with <200W load. And then me not paying attention with the
Traco BCMU's 12VDC. Using the 2-relay/3-switch module, remotely I
could see that the "Batt OK" contact was open after power came back up
at the site at like 4am and still open around 8am. Since the site went
down sooner than expected, I figured either the battery fuse on the
BCM blew or it was sensing some other issue. So I get there and put my
clamp-on ammeter on it and zero current. Two fused 20AH batteries in
parallel both sitting at 13.1 volts. OK, WTF. Then it all made sense
with the shunt.
Another thought I had is... what about Hall effect sensors? Could you
do a module for that? That would be pretty cool.
On 6/16/2017 11:00 AM, Forrest Christian (List Account) wrote:
There will likely be a 20A shunt in our future. I'm in the process
of redesigning these so that they're less expensive to build since
the existing design is being sold at or possibly below cost. I'm
trying to end up with a 20A shunt as a result but I don't know for
sure if this will happen.
On Jun 15, 2017 5:47 PM, "George Skorup" <george.sko...@cbcast.com
<mailto:george.sko...@cbcast.com>> wrote:
Forrest,
Would you be willing to make a 20A shunt? Would the traces on
your current design handle it?
Reason I'm asking is... I'm stupid. I had a 10A shunt on the batt
negative side of a Traco BCMU360. Didn't occur to me that 230
watts @ ~12VDC can get up to 20A. So the shunt went kaput after
about 25 minutes and the site went down. Not a problem at most
other sites with less load. This one happens to be the most
heavily loaded with two Trango ApexPlus, various APs and PTPs
plus the DC-DC inefficiencies.
