[RE-wrenches] strings of older solar panels

[Howie Michaelson]

Allan,

I replaced 14 MSX 60's (I believe) for a client.  They were showing about
1/2 their expected power output even though they seemed to have an
acceptable voltage and current range.  Several had bubbles in the tevlar
backing and some showed burn marks through the tevlar at what seemed to be
the solder joints.  Does this sound like similar symptoms to the defective
modules you referred to?

Thanks,
Howie
-- 
Howie Michaelson
NABCEP Certified Solar PV Installer™

Sun Catcher, LLC
Renewable Energy Systems Sales and Service
VT Solar & Wind Incentive Program Partner
http://www.SunCatcherVT.com
(cell) 802-272-0004
(home) 802-439-6096


On Wed, November 18, 2009 2:03 pm, Allan Sindelar wrote:
>
> Lee,
>
> Note also that the MSX series was known to have some defective modules.
> They
> showed correct Voc and Isc but essentially a flat I/V curve slope, meaning
> very weak output; that was a real headscratcher for installers. I had a
> set
> of 12 from around 1994 with this behavior. Solarex never recalled this bad
> series, but I heard about it from another old-timer. Solarex replaced all
> of
> mine under warranty, but warranties back then were 10 or 12 years, so by
> now
> expired. Of course, back then there was a Solarex. But they knew which
> serial numbers were prone to be defective.
>
>
>
> I would encourage you to test array output before putting any effort into
> making it a GT system. If these are low output, push hard on BP(?) to
> cover
> them as known to be defective.
>
>
>
> Allan Sindelar
>
> Allan at 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 <http://www.positiveenergysolar.com/>
>
>
>
> From: re-wrenches-bounces at lists.re-wrenches.org
> [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Brian
> Teitelbaum
> Sent: Wednesday, November 18, 2009 11:33 AM
> To: RE-wrenches
> Subject: Re: [RE-wrenches] strings of older solar panels
>
>
>
> Lee,
>
>
>
> I also have an old spec sheet for the MSX60/64 that does not state the max
> system voltage. It does, however, state that it passes a 2700VDC
> frame/cell
> isolation test. I don't know if that is the required test for a 600VDC
> rating or not.
>
>
>
> If I remember correctly, they were not sold with bypass diodes installed,
> so
> if you do use them in a system above 24V, be sure to add the diodes.
>
>
>
> Brian Teitelbaum
>
> AEE Solar
>
>
>
>
>
>
>
> From: re-wrenches-bounces at lists.re-wrenches.org
> [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Solar
> Plexus
> Sent: Wednesday, November 18, 2009 9:33 AM
> To: RE-wrenches at lists.re-wrenches.org
> Subject: [RE-wrenches] strings of older solar panels
>
>
>
> Hi Wrenches.
>
>
>
>             I have a customer with 32 of the Solarex MSX-64 solar panels
> an
> a battery-based system.  He wants to go batteryless inverter.  So I am
> looking at  2 strings of 16 in series.    But the solar panel spec sheet
> doesn't say anything about system voltage rating.  Can I do this?
>
>              If  one solar panel in the string is shaded, does it see the
> full string voltage of around 280 volts?  Is there something in the way
> new
> panels are made that makes them more able to handle this voltage, or is it
> just that they are now tested for it?
>
>             My guess is this request may be happenning a fair amount.  Is
> there a reason these panels are not listed on the California GoSolr
> website?
>
>
>
> Lee Tavenner
>
> Solar Plexus
>
>