Growatt Error 407: Self-Test (Autotest) Failed
Error 407 means the Growatt's grid-protection self-test (autotest) failed. In some regions, the grid code requires the inverter to run a self-test of its grid-protection limits before it connects. If that test does not complete successfully, the inverter shows Error 407 and waits. It often passes on a retry once the grid is stable.
What usually causes Error 407
- An unstable grid during the test. If the voltage or frequency is wandering, the self-test can fail; it usually passes when the grid settles.
- A grid that is briefly out of the test's expected range.
- Rarely, an internal issue if it never passes.
What to do
- Restart the inverter and let the self-test run again. AC breaker off, then the DC isolator, wait 5 minutes, restart. The self-test repeats on start-up and often passes when the grid is stable.
- Try at a calmer time. If the grid is unstable (for example during peak load), the test is more likely to fail. A retry later can succeed.
- If it never passes, contact your installer or Growatt. They can review the grid-code settings and the test result.
Related Growatt codes
FAQ
What is the self-test for?
In regions whose grid code requires it, the inverter checks that its grid-protection thresholds (voltage and frequency limits) work correctly before it starts exporting. It is a compliance and safety check, not a sign of damage.
Sources
- Growatt inverter user manual and error-code reference (Error 407 = autotest failed; restart and repeat the self-test, contact Growatt if it persists).
- Growatt installer documentation.
⚠️ Safety disclaimer. Solar inverters carry lethal DC and AC voltage even when "off". This guide covers a safe restart and retry only. Grid-code settings should be handled by a licensed installer.