[RE-wrenches] Matching modules into Xantrex GT

[Andrew Truitt]

William -

Over powering is not an issue.  You might clip a little power occasionally,
but the loss will be minute and you won't damage or void the warranty of the
inverter.   And since your talking separate strings, the current mismatch is
a non-issue.  The only loss you will incur will be due to your voltage
mismatch,  and I suspect it will be somewhere is the neighborhood of 2.5%

1 - (382 / 403) = .05
.05 / 2 = .025

Make sense?  (I'm a little hung over so forgive me if it doesn't)

Andrew Truitt
Truitt Renewable Energy Consulting
202 486-7507
http://www.linkedin.com/pub/andrew-truitt/8/622/713


Please excuse brevity and typos - this message was typed on tiny keys.

On Jan 15, 2011 11:44 AM, "William Miller" <william at millersolar.com> wrote:

 Friends:

I have a client with a Xantrex GT2.8 inverter.  Feeding it are 8 Solar World
SW175 modules.  This is half the modules that this inverter can handle.  The
client wants to realize the full potential of this inverter.  Adding 8
additional SW175 modules would be ideal, but they are no longer
manufactured.

I need to find a group of modules to match the 175s.  I am contemplating 9
SW240s.  The specifications for this match up are below.  I imagine the IV
curves are similar for these two modules as they are the same chemistry and
the same manufacturer.

        8-SW175 9-SW240
Voc     403             382
Vmp     283             275
Imp     4.95            7.87
Pcsi    1252            1715
Ptotal  2.967

Might this match be close enough?  I know this over-powers the inverter
slightly.  I imagine that the Xantrex will self regulate this very rare over
wattage condition.

Comments?

William Miller



 *Please note new e-mail address and domain:

*William Miller
Miller Solar
Voice :805-438-5600
email: william at millersolar.com
http://millersolar.com
License No. C-10-773985

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