Two parallel strings with different voltage

[J.P.M.]

Thank you SunEagle for a quick reply.

However on a closer scrutiny I found that in morning string 1 is producing higher than the string 2 and in afternoon or early evening string 2 takes the lead. So it must be the sun playing tricks along its path. In case I find something else then will post it in next few days.

Thanks.

Have you or can you actually go outside and look at the panels at various times or day or at various times of the year ? Sometimes the eye is a good diagnostic tool.

Sounds like a shading problem might be the culprit as # 2 of Suneagle's post.

Put a good eyeball on the array when its sunny and when the string voltages/currents are not close to one another. Bet you find the array partially shaded.