Good info Larry, do you think the frame is problematic enough that it
wouldn't work with regular top down type hardware?
My customer also confirmed he had no labeling on his modules.
R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760
On 8/21/2014 2:26 PM, Larry Crutcher, Starlight Solar Power Systems wrote:
Hello Ray,
I have been installing SunPower cell modules for about a decade. All of our
mobile installations are ungrounded arrays, off grid we use negative ground. We
have never had any issue using them to charge batteries up to 48 volts, even
when combined in series. I have not installed any for grid tie.
Last year I purchased about 100 of the 327 and 435 Watt modules, likely from
the same seller, for a very low price. There is no SunPower label on the back.
I was told that these modules were laminates that SunPower rejected due to
cosmetic flaws. The surface has lots of blemishes clearly visible under the
glass. Someone other than SunPower made frames and assembled the module. The
frame quality is not so great and the 435 structurally feels inadequate. I sell
these to off grid customers in Mexico that want cheap but high performance PV
solar power.
That’s all...
Larry Crutcher
Starlight Solar Power Systems
On Aug 20, 2014, at 10:46 PM, Ray Walters <r...@solarray.com> wrote:
Greetings fellow Wrenches;
I have a customer that just purchased some Sunpower E20 -435 modules somehow
from Ebay, and wants me to design a backup power system for him.
This system would be battery based and not be grid tied. SO the question is:
has Sunpower put to rest the positive grounding issue with these modules?
I would want to either use a negative ground system or go ungrounded, as the
charge controllers and battery based inverter do not play well with a positive
grounded system.
My idea is that I could run these modules at lower voltage, either all in
parallel (85.6 Voc) or 2 in series (191 Voc) with Midnite Classic controllers,
and that the whole surface polarization issue will be minimized at these lower
voltages.
I know this came up before, and Sunpower basically said they would revoke their
warranty for any battery based systems, (which is why I'm no longer a Sunpower
dealer.... :)
Don't the newer Sunpower modules no longer need positive ground, and if so,
which models is this true for? In this case, the warranty is already suspect,
so that's not an issue. It just has to work safely.
Thanks in advance for your help,
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