Please ensure that there is no polarity reversal of the strands.
To determine the correct polarity of optimised strings, a resistance or impedance measurement must be carried out. For this purpose, the resistance must be measured in both directions.
The measuring direction with the higher measured resistance is automatically the correct polarity (+ pole from the meter = PV+ at the inverter).
Each 450W-P optimiser has an internal resistance of 1kOhm (+-10%). As an example, a string with 10 optimisers is measured at 10kOhm (+-10%).
Hint:
Reversing the polarity of a PV string at the inverter will result in the optimisers not being enabled. Alarms with the ID 2011 and/or 2012 will most likely be displayed. Please correct the plug-in direction.