How do I fix PV Midpoint Insulation Low (Alarm 1029) on a Solis?

Note the timing. Early morning, late afternoon or rainy day reports are usually moisture and clear when dry. Then: Measure string to earth resistance, it should be above 20 kOhm. Investigate the string cabling if low.

Solis

PvMidIso

PV Midpoint Insulation Low (Alarm 1029)

PV middle point insulation protection. PVGndRun variant means a PV terminal is grounded during operation.

Common causes

Morning dew or rain lowering insulationDamaged string cable insulationN to PE connection issue

What to check

STEP 1

Note the timing. Early morning, late afternoon or rainy day reports are usually moisture and clear when dry.

STEP 2

Measure string to earth resistance, it should be above 20 kOhm. Investigate the string cabling if low.

Escalate if

Resistance healthy and dry weather but alarm persists, try a firmware update first

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