RISO seems low

silverpulser · Sep 7, 2016

Hi, I have a 16 panel 4Kw solar panel system which is now 4 years old. The inverter is an Aurora Uno and is configured with two strings (SW and SE facing roof elevations).

Recently my RISO in the mornings has dropped from an admittedly already lower than ideal 10Mohms to a new low of 3.2Mohms and 2.6Mohms over the last two days.

I know that Aurora say that anything over 1Mohm is OK but when installed and for a good while afterwards it measured 20Mohms.

Should I be concerned?

Shaun

Gavin A · Sep 7, 2016

if it keeps dropping then it indicates a likely problem, good to keep a note of the weather conditions when it's worst - ie if it's when it's wet / wet and cold / dry and sunny etc as that helps to narrow down the likely issue.

silverpulser · Sep 9, 2016

Gavin A said:
if it keeps dropping then it indicates a likely problem, good to keep a note of the weather conditions when it's worst - ie if it's when it's wet / wet and cold / dry and sunny etc as that helps to narrow down the likely issue.

The low readings followed a couple of days of light rain. Yesterday it had increased back up to 9.9Mo after a couple of fine days.