[RE-wrenches] not sure what's going on here

[Larry Crutcher, Starlight Solar Power Systems]

I have a tendency to read between the lines and try and perceive things unstated. Just my nature. I doubt that the module removed from the circuit stays at 13Vdc. Ron said "...the normal voltages return but drop again in about 15 min". Because of the 3024 software issue I think this is affecting all modules. Also, " the individual output from each panel when unhooked and tested in full sun show about 35v". Each meaning the 3 or all 4? Ron, please clarify this. Have you been to the site or was this the report from the owner?

Anyone that says, "41 years in solar energy …" is bound to be an enlightened, albeit aged fellow. Wear it as a badge. Actually the reference was in general as I view most of us battery wrenches as graybeards.

Larry 





On May 12, 2013, at 7:45 AM, Exeltech <exeltech at yahoo.com> wrote:

Hello Larry,

A firmware upgrade may address some aspects of the issue, and
is certainly a recommendation, but it doesn't account for the
one PV that exhibits 13Vdc output when it's completely out of
the circuit.

That characteristic clearly exemplifies a failure within the PV
module itself.

It's entirely possible more than one failure mechanism is involved
here, such as something within the PV, and other that's related
to the firmware.  Multiple-issue failures are some of the most
frustrating and challenging of all fault analyses.  Then add
distance to the equation ....


Thanks too for the reference to "aged".


Dan


--- On Sun, 5/12/13, Larry Crutcher, Starlight Solar Power Systems <larry at starlightsolar.com> wrote:

> From: Larry Crutcher, Starlight Solar Power Systems <larry at starlightsolar.com>
> Subject: Re: [RE-wrenches] not sure what's going on here
> To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
> Date: Sunday, May 12, 2013, 9:30 AM
> Fellow Wrenches,
> 
> I realize that many of you are offering your time and
> comments in a genuine effort to help Ron, however, the
> problem he described is the EXACT behavior of all early
> 3024i controllers. This happened with overloaded controllers
> operating in 24 to 12 downconversion, just like in this
> case. When the 3024 would reach current limiting, the
> controller will lock itself to half the input voltage.
> Because high power is still available, the controller would
> still function and many did not even know they had a
> problem. By disconnecting PV and battery and reconnecting,
> the 3024 will reboot and the problem will not occur again
> until current limit is reached. Note that this only happens
> when using high voltage PV and down converting to 12Vdc.
> 
> Blue Sky Energy is our #1 selling controller and we have
> installed over 500 3024i's and 3024iL's. When I first
> discovered this issue and reported it, Rick at Blue Sky was
> able to duplicate it and made appropriate changes. Upgrading
> firmware always corrected the issue.  So, with respect
> to the many aged but wonderful minds on this list, I highly
> suggest the controller upgrade first. At the very least,
> reboot the controller in the morning and observe as it
> reaches the limit.
> 
> Larry Crutcher
> 
>