Growatt inverter shows AC F Outrange (Error 304)

Error 304 AC F Outrange means the supply frequency is outside what the Growatt inverter accepts. On the WAPDA grid this is rare. It usually means the inverter is seeing a generator, whose frequency drifts as loads change.

Growatt Error 304 Frequency | Faisalabad, Lahore

What you will see

Error 304 while a generator is running
Inverter will not connect on generator but works on grid

Why it happens

Small generators speed up and slow down with load, so their frequency moves out of range for an on-grid inverter.

Diagram

Grid or generator

WAPDA grid

GridSteady frequency

→

InverterRunning

Generator

GeneratorDrifts with load

→

InverterError 304

Applies to Growatt MIN, MOD, MID and SPH inverters.

What you can check yourself

Note whether it only happens on generator
Check which source the changeover was on

What not to do

Do not connect generator power to an on-grid inverter without an engineer's design

When to call us

Measure frequency on grid and generator
Check changeover wiring so the inverter is isolated on generator

Generators in Punjab

Many homes and factories in Faisalabad and Lahore still run generators. We check how yours is wired against the Growatt inverter.

Send us

the alarm photo, generator size and a photo of the changeover