Internal Relay Test Failure

What does K1-Close mean?

An internal self-test for a relay (K1) within the Sunny Boy SB50US-80US-IUS094030 inverter has failed. This indicates a potential malfunction of the relay or its control circuit.

• Failure during internal relay K1 self-test.

Click steps to track your progress.

1. 1

   Verify DC input voltage from the PV array is within the inverter's specified operating range.

2. 2

   Verify AC grid voltage and frequency at the inverter's output terminals are stable and within specified limits.

3. 3

   Inspect all external DC and AC cabling connections for signs of looseness, corrosion, or damage that could interfere with inverter operation or internal diagnostics.

4. 4

   Access the inverter's display or monitoring portal to check for additional fault codes, warnings, or operational history that could provide context for the K1 relay failure.

5. 5

   Perform a complete shutdown and restart of the inverter using the disconnects according to SMA's recommended procedure.