Take a charge controller with you that is sized for that array.
R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760
On 5/12/2013 11:57 PM, Ron Young wrote:
Hello all and thank you for the illuminating replies. One thing that
immediately comes to mind is that I (we) are relying on the clients description
of what is going on. I have not visited the site but it looks like it's in the
cards as this seems like it could be a problem with several moving parts. The
description I received from the owner is as follows:
1/ one of the 4 modules is only putting out about 13 volts. This is a
persistent condition and does not go away. So from this I conclude that diodes
have failed.
2/ the remaining 3 modules connected to the 3024i operate in a normal voltage range
but after about 15 minutes drop to around 13 volts. Once disconnected from the
controller then reconnected this condition repeats: normal then dropout after about
15 min. So from this I conclude that either the firmware is at fault or there is
another cause as suggested by Dan "heating of the PV is causing one or more
bypass diodes in one or more of the remaining
modules to fail short intermittently".
I'll try and work out a site visit to chase this one down and report back. I've
also emailed Rick at Blue Sky. Once again thanks for the considered responses.
Ron Young
On 2013-05-12, at 10:22 AM, "Larry Crutcher, Starlight Solar Power Systems"
<la...@starlightsolar.com> wrote:
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 <exelt...@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
<la...@starlightsolar.com> wrote:
From: Larry Crutcher, Starlight Solar Power Systems <la...@starlightsolar.com>
Subject: Re: [RE-wrenches] not sure what's going on here
To: "RE-wrenches" <re-wrenches@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
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