To safely measure the Voc of a PV string connected to a combiner box, the technician should:

To safely measure the Voc of a PV string

Multiple choice — select the best answer

AMeasure at the combiner bus bars with all other strings connected
BShort all strings together at the combiner input before measuring
CMeasure at the inverter DC input terminals while the inverter is running
DDisconnect the string under test at the combiner input and measure at the string conductors

✓ Correct answer: D. Disconnect the string under test at the combiner input and measure at the string conductors The safest practice is to isolate the string at the combiner input by opening or removing its fuse/OCPD, then measure Voc at the string conductors. This prevents interaction with other strings and ensures the meter reads only the string under test.

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To safely measure the Voc of a PV string connected to a combiner box, the technician should:

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