PV String Balance / Ground Fault

Differential leakage or balance fault detected between PV1 and PV2 inputs.

Common causes

One string has higher leakage than the otherPanel junction box seal failure on one stringCable insulation damage on one string only

What to check

STEP 1

Perform per-string IR test at 500V DC. The string with lower resistance is the leaky one. Inspect MC4 connectors and junction boxes on that string

STEP 2

Temporarily operate on one string only to confirm which string carries the fault

Escalate if

Both strings pass IR test but fault persists on reconnection -- may indicate inverter input circuit issue, escalate

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