"A Fronius IG 4000 is doing some weird cycling. Every 45 seconds the voltage pops up to Voc and drops back to Vmp immediately followed by a downward ramp of voltage and corresponding rise in current. This repeats continuously."
We had this symptom on about 20% of our Fronius systems, years ago. The operating point would ramp up to maximum power, then quickly drop down to about 60% of power, then slowly ramp back up, etc, with a 45 sec periodicity. It seemed to be worst when the DC operating voltage of the array is close to the AC line voltage. Discussed with Fronius; no resolution. We tend to not use Fronius any more due to this issue. Mark Byington Cobalt Power Systems _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
