How do I fix Grid Sync Error (3P, 78/8x2D) on a SolarEdge?

Measure and log grid voltage and frequency stability at the inverter. Then: Check AC terminations are sound.

SolarEdge

Grid Sync Error

Grid Sync Error (3P, 78/8x2D)

Cannot synchronise because grid voltage or frequency is unstable.

Common causes

Unstable supplyLoose AC terminations

What to check

STEP 1

Measure and log grid voltage and frequency stability at the inverter.

STEP 2

Check AC terminations are sound.

Escalate if

Stable measurements but fault persists

Need full interactive diagnosis?

Faultpath walks you through decision trees, fault codes, and commissioning — built for solar & battery engineers.