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Usually self-clears

Growatt Error 302: No AC Connection

Updated June 2026 · Reviewed for technical accuracy · ~3 min read

Error 302 (no AC connection, sometimes shown as "No Utility") means the Growatt cannot detect the grid, so it stops exporting and waits. Most of the time this is not a fault: it is a power cut or a tripped breaker on the AC side. When mains power returns, Error 302 normally clears by itself.

Grid, wiring, or inverter?

  • A utility outage. Check whether the rest of the house has power. If the whole place is out, it is a grid cut, just wait.
  • A tripped breaker or open isolator on the AC line between the inverter and the meter.
  • A loose AC connection at the inverter or board.

How to check it safely

  1. Is there a power cut? Look at the rest of the house. If the grid is down, Error 302 clears when power returns. Nothing to fix.
  2. Check the AC breaker. Find the breaker between the inverter and the grid and make sure it is on; reset it if it tripped.
  3. Confirm the main supply has power.
  4. Allow the reconnection delay. After power returns, the inverter waits a short, standards-required time before it comes back online. This pause is normal.
  5. Grid present but Error 302 stays? Power-cycle once. If it still won't connect, the AC connection may need an installer's look.

Quick decision flowchart

Error 302 appears
↓ is the rest of the house also without power?
✅ Yes, whole house out → grid cut. Wait; it clears when power returns.
❌ No, house has power → check the AC breaker to the inverter.

Related Growatt codes

Error 300, AC voltage Error 304, AC frequency Error 303, N-PE voltage

FAQ

Error 302 shows but my house has power.

The inverter sees the grid only through its own AC connection. If a breaker on that line is off or a connection is loose, it reads "no AC" even though the house is powered. Check that breaker first.

Sources

  • Growatt inverter user manual and error-code reference (Error 302 = no AC connection; check AC wiring and breaker status).
  • Growatt installer documentation.
⚠️ Safety disclaimer. Solar inverters carry lethal DC and AC voltage even when "off". This guide covers external, switch-level steps only. Never open the unit or work on wiring unless qualified. When in doubt, call a licensed installer or electrician.