boB,
The Mitsubishi system is just two parallel strings. The combiner was
planned for future expansion. It was last fall that I had trouble with
those so I don't remember if they were "off" or "tripped". The system
with Evergreen panels is just three strings; it is possible but not
likely that the problem is a fault in the array. I found that breaker
in the "off" position. And that is strange, because it is really
unlikely that anyone has been in the combiner box during the last year.
Kent
boB Gudgel wrote:
Kent Osterberg wrote:
Allan,
I've had trouble with breakers opening when they shouldn't. On an
array of two strings of Mitsubishi 175s (Isc = 7.9A) I had two 15-A
breakers open. Last week, I had a low-power call from a customer
with three strings of Evergreen 190s (Isc = 7.1A); one 15-A breaker
in the combiner was open. Most of my installs are around 3000 ft
elevation, so the irradiance is possibly a little higher than normal,
but not by enough that it should be an issue for 15-amp breakers. If
this is a wide-spread problem, I'd expect others on this list to have
noticed.
Hi Kent,
Could there be a defective module and the breaker is just doing what
it is supposed to do ?? What is the series fuse rating for those
modules ? (probably 15A?) A shorted or defective module would cause
those other strings to make it trip, if there are enough
parallel strings. I hope there isn't some kind of intermittent
problem...
Was the breaker actually in the "tripped" position or the "off"
position, since there is a difference? (tripped of course means
that there is some play in the lever.)
We (and OB) have sold literally over a million (or millions?) of these
breakers and we just haven't seen any problems. You have been
using these breakers for years now... Have you seen problems before
this ?? I understand that any problems with CBI breakers
have been AC breakers, not DC, and even then, problems have been far
and few between.
You could test the breakers though... Just shove, say, 10 Amps
through one of the questionable breakers and see if it trips after a
while.
It seems kind of odd that more than one of these breakers would have
defectively tripped near the same time ( week ? day? week-day?).
There is, I suppose, the possibility that they could all of a sudden
have started having some kind of problem, but CBI breakers have
had an excellent track record for many years now. We haven't heard
anything from any other customers here at MidNite.
Can't wait to hear what's causing this problem though... I'm sure it
will be very interesting !
boB
As others have mentioned, it is important to take precautions to make
sure that stranded wires are well tightened in these breakers. I
tighten, wiggle, re-tighten, and then check again later. On systems
where I've had breakers open, loose connections haven't been the issue.
Kent Osterberg
Blue Mountain Solar, Inc.
www.bluemoutainsolar.com <http://www.bluemoutainsolar.com/>
Allan Sindelar wrote:
I have had no problems to date, Kent. Can you be more specific as to
what
problems you have had?
Allan Sindelar
al...@positiveenergysolar.com
NABCEP Certified Photovoltaic Installer
EE98J Journeyman Electrician
Positive Energy, Inc.
3201 Calle Marie
Santa Fe, New Mexico 87507
505 424-1112
www.positiveenergysolar.com
-----Original Message-----
Is it just me, or have other wrenches had problems with the CBI
circuit breakers used in the Outback or Midnite combiner boxes?
Kent Osterberg
Blue Mountain Solar, Inc.
http://www.bluemountainsolar.com/
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