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Diagnostics case :

K1-Open, K2-Open, K1-Close, K2-Close

Yellow LED in Blink Code 5 or Permanent Disable (yellow LED continuously illuminated)

(en) The error messages K1-Disconnect/K2-Disconnect and K1-Close/K2-Close indicate a disturbance of the grid relays in the inverter. The inverter checks the grid relays before connecting to the grid. If there are problems “opening” or “closing” the relays, for safety reasons the inverter will not connect to the grid.

At first, the yellow LED flashes code 5 and the inverter repeats the relay test. If the disturbance occurs frequently, for safety reasons the inverter switches to Permanent Disable Mode and the yellow LED is continuously illuminated.

Information: Inverter grid relays can be damaged by the use of screw-type fuses as load-break switches. A screw-type fuse element, e.g. DIAZED fuse or NEOZED fuse, does not have load-break properties and may therefore only be used as cable protection, not as a load-break switch.

More information about this can be found in the inverter’s installation or operating manual as well as in the technical information “Circuit Breakers” in the download area under https://www.sma.de/en/service/downloads.html.

If the message only appears very rarely (a maximum of once or twice a week), no further action has to be taken. In this case, the next step is to continue to monitor the device.

However, if the message repeats or persists, the device must be replaced.

In this case, please contact SMA Service with the following information:

• Device type and serial number of the inverter

• If the device is in the warranty period: the warranty certificate

• LED blink code and error message

• Are screw-type fuses used as load-break switches in the installation?

• How long has the error been present for? Is it sporadic or continuous?

All work on the inverter and the cabling of the PV array must be carried out by an electrically qualified person. SMA accepts no liability for the information and solutions given in the Online Service Center. Additional information can be found in our Online Service Center’s terms and conditions of use.