[RE-wrenches] Kyocera 120's low voltage

[Dave]

Wrenches,

 

I troubleshot an underperforming off grid array today and found low Voc's in
4 out of 10 KC-120's (nominal 12v modules rated at 21.5 Voc and 7.45 Isc).
Modules are vintage 2000.

Under modest sunlight (500 to 600W per M sqd) 6 modules measured from 18 to
19 Voc and 4 Isc. Four modules measured from 9.6 to 13.7 Voc and 4 Isc.

 

I was chased off the roof by a coming thunderstorm and did not check for bad
diodes. These modules have nice old school J-boxes with 6 diodes per each
module.

 

Am I looking at a diode issue, or failing modules?

 

Thanking you in advance for your time,

 

David Palumbo 

Independent Power LLC

462 Solar Way Drive

Hyde Park, VT 05655

802-888-7194

 

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