Is your SMA Sunnyboy solar inverter showing an error K1 Open message? If so your solar power system isn’t working, so you’ve done the right thing by coming here and doing something about it.
Error K1 Open – What does it mean?
The Error K1 Open message on an SMA Sunnyboy inverter is referring to the grid relay inside the inverter, relay K1. When the inverter is off or there is no sunlight available it is completely normal for the K1 relay to be open, however when solar power is available the K1 relay will try to close so it can send power from the inverter into the grid. If the K1 relay isn’t closing when the sun is out your system won’t work and the inverter will throw this error. The Error K1 Open is an internal fault with your inverter.
“Error K1 Open” – How do you fix it?
SMA Sunnyboy solar inverters are generally very reliable, so hopefully you can get your inverter back in action. The first thing we recommend with an issue like this is to try a full reboot of your system by completing the following in order:
Turn OFF the solar supply main switch (or inverter AC isolator if present).
Turn OFF the PV array DC isolator.
Wait for the inverter screen to go completely blank and the red fault light to turn off.
Turn ON the PV array DC isolator.
Turn ON the solar supply main switch (or inverter AC isolator if present).
Wait a few minutes while the inverter boots back up.
If a reboot didn’t help…
If after rebooting the inverter you see the same error message, unfortunately, it sounds like you have a permanent error that is going to require professional help. The Error K1 Open fault will be covered under the SMA inverter warranty however if you are seeing this issue I’m guessing the inverter is outside the standard manufacturer’s 5-year warranty. The SMA Sunnyboy SB1100, SB1700, and SB2500 were manufactured more than 5 years ago now so it’s highly unlikely your warranty extended longer than that.
You can potentially have the internal issue with your inverter repaired however this will be at a substantial cost and still leave you with an inverter that isn’t covered by warranty. For this reason, we highly recommend replacing the faulty inverter with a new quality unit backed by a new manufacturer’s warranty. If you are in South East QLD somewhere near the Gold Coast or Brisbane area we can help.
For further advice please complete the form above under the URGENT heading and we’ll assist you further.