Update - after 2 visits each with a new version of the firmware Samil emailed me with a firmware upgrade which seems ot work. The 2 strings are now showing within a few watts under identical conditions. Apparently the issue was with the way the 2 strings were tracked.
A replacement Samil Solar River 4000TL-D was provided by Samil with firmware version 1.90 and the installer fitted it. The apparent difference between PV1 and PV2 output was still evident even when string swapped round so original inverter was refitted. Samil say they have a similar problem in...
I have an indentical issue. A Samil Solar River 4000TL-D connected to 2x8 panel strings. PV1 always shows higher power output in all conditions by around 5%. installer diagnosed panels are OK by swapping inputs to inverter. New inverter arrived today so will see if there is a difference.
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