SPH 3000–6000TL BL-UP / SPH 4000–10000TL3 BH-UP hybrid (Error 2xx–6xx codes)
Growatt Error 304 error code
Grid frequency is outside the inverter's configured frequency window.
Likely causes
- Grid frequency drift from the utility
- Generator supply running off 50 Hz
- Inverter set to the wrong 50/60 Hz country standard
- Loose AC input wiring causing unstable frequency sensing
Checks to run, in order
- 1Measure grid frequency at the inverter AC input
- 2Compare with the 50 Hz local standard and the inverter's grid setting
- 3Confirm whether the site is inverter, generator or hybrid supplied
- 4Inspect AC input terminals for looseness
Fixes
- Set the correct grid standard/country for the site
- Stabilise or service the generator before retrying
- Restart the inverter and recheck the frequency reading
When to escalate
If the measured frequency is within the permissible range and Error 304 persists, ask Growatt support to review the grid-sense circuit.
Fix it with the right tools
Check the system around the fault before replacing parts: load, battery bank, PV string and commissioning settings. If you need a second opinion, send the code and your inverter model to our team.
Before you open the inverter
- Isolate both the AC and DC sides, then confirm the display is dead before touching terminals.
- Use insulated tools and one hand where possible. DC arcs do not self-extinguish like AC.
- If you see burnt terminals, swollen cells, leaking electrolyte or a burning smell, stop and escalate instead of resetting the fault.
Questions installers ask
What does Growatt Error 304 mean?
Grid frequency is outside the inverter's configured frequency window.
How do I fix Growatt Error 304?
Set the correct grid standard/country for the site Stabilise or service the generator before retrying Restart the inverter and recheck the frequency reading
When should I escalate Growatt Error 304?
If the measured frequency is within the permissible range and Error 304 persists, ask Growatt support to review the grid-sense circuit.
Can I reset Growatt Error 304 myself?
Only after isolating the AC and DC sides and running the checks above. If Growatt Error 304 returns immediately, stop resetting it and escalate; a repeating fault usually points to a real circuit, battery or hardware problem.
Which models show Growatt Error 304?
Growatt Error 304 is documented for SPH 3000–6000TL BL-UP / SPH 4000–10000TL3 BH-UP hybrid (Error 2xx–6xx codes). Confirm the code on your own unit's display or manual before ordering parts.
More Growatt error codes
- Growatt 01Fan is locked (displayed as F01 on the SPF ES Lite).
- Growatt 02Internal component temperature is over 100 °C (F02 on the ES Lite).
- Growatt 03Battery is over-charged / battery voltage is too high (F03 on the ES Lite).
- Growatt 04Battery voltage low.
- Growatt 05Output is short-circuited (F05 on the ES Lite).
- Growatt 06Output voltage is too high. The manual groups 06/58 as 'output abnormal' — inverter voltage above 150 Vac or below 40 Vac.
Guidance reviewed 17 October 2026 by the Mishka Energy installer team. Error codes vary by brand, model family and firmware; confirm against the manufacturer manual.
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