How do I fix Boost Capacitor Overvoltage Fault on a Sungrow?

Disconnect AC circuit breaker and DC switch (and battery switches if present). Wait 15 minutes. Then: Close AC circuit breaker, then DC switch. Monitor for normal operation.

Sungrow

SG-026 · IDs 364–395

Boost Capacitor Overvoltage Fault

Critical overvoltage at boost capacitor stage — inverter has shut down.

Common causes

Internal boost circuit faultInput voltage exceeding design limits

What to check

STEP 1

Disconnect AC circuit breaker and DC switch (and battery switches if present). Wait 15 minutes.

STEP 2

Close AC circuit breaker, then DC switch. Monitor for normal operation.

Escalate if

Fault recurs after restart — contact Sungrow support

Need full interactive diagnosis?

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

Open Faultpath

More Sungrow fault codes

SG-001 · IDs 2,3,14,15