How do I fix Grid Under-Frequency on a Solis?

Usually transient — wait for auto-recovery. Persistent fault indicates grid or setting issue Then: Check G98/G99 frequency threshold settings in inverter parameters

Solis

E004

Grid Under-Frequency

Grid frequency below 47.5 Hz limit. Inverter disconnects.

Common causes

Grid instabilityDNO frequency event

What to check

STEP 1

Usually transient — wait for auto-recovery. Persistent fault indicates grid or setting issue

STEP 2

Check G98/G99 frequency threshold settings in inverter parameters

Escalate if

Recurring fault — report to DNO with frequency log from Solis app

Need full interactive diagnosis?

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

Open Faultpath

More Solis fault codes