[RE-wrenches] Cracking Backing on Sharp NT-175U1 Modules

[Brian Sipp]

Thanks David, that seems in line with what I’m seeing too.  These are all
tilted at approx. 20 deg on an unpainted flat metal roof so there is
reflection that could occur in the early morning and late afternoon.  I
can’t help but think that this isn’t an unforeseen design consideration
   

 

Brian Sipp

First Source Solar

530-554-1925

 

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of David
Brearley
Sent: Saturday, February 23, 2013 11:09 AM
To: RE-wrenches
Subject: Re: [RE-wrenches] Cracking Backing on Sharp NT-175U1 Modules

 

FWIW: I recently saw something similar at an installation in Central Texas
that uses a similar product. The cracking in the weatherproof coating was
highly localized, affecting ±8 out of ±48 modules. The affected modules
differed from the others only in terms of the amount of reflected light
incident on the back of the devices. (A shed roof installed over an ATV was
reflecting sunlight up underneath a portion of a top of pole mounted array.)
While the weatherproof material showed signs of accelerated aging—perhaps
due to heat effects, reflected UV effects, or both—we could not measure any
difference in performance using a multimeter. However, we did not have an
I-V curve tracer with us and the irradiance was relatively low while we were
at the site. 

 

On Feb 21, 2013, at 11:11 PM, Brian Sipp wrote:





I inherited the service work on a couple of small commercial PV systems that
were installed by another company about 7 years ago.  The systems are Sharp
NT-175U1 modules and Sharp JH3500U inverters.  This client has been losing
inverters at a rate of one or two per year for the last couple of years.
When I was on-site yesterday, I noticed that the backing on all of the
modules (there are 120 modules at this site) looks like it’s starting to
shrink and crack all over.  I’ve started an inquiry with Sharp but
considering their level of response to the high number of inverter failures,
I figured I’d come here before they get me doing diagnostic backflips. 

 

To  be clear, this is the clear part of the backing I think Sharp is calling
the “weatherproof coating.”  It does not seem to have affected the white EVA
part of the backing.  However, the points in the EVA where these cracks run
over the solder points between the cells seems to be very thin and I can see
the dark color of the solder showing through more than elsewhere.  By the
time I got done with my testing on specific inverter problems and noticed
the panels, I didn’t have any more time to do further testing for power
output of the modules/strings so I don’t have any specific test results to
share.  My concern here is that this is the beginning of a bigger problem.
Has anyone else had this experience?

 

Brian Sipp

First Source Solar

www.FirstSourceSolar.com

530-554-1925

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