I have the same error code on my SB 4000 and believe that the problem may be combined effects of (a) elevated AC voltage at the inverter - 4-5v @ 10A - due to cable resistance, and (b) inherently high line voltage up to 251v. So I’m thinking of replacing the 11metres of 1.5mm t&e connecting the inverter to the domestic supply with 4mm so that the voltage elevation at the inverter is reduced.
- The inverter disconnects when the line voltage measured by the inverter is 255-256v.
- When the inverter disconnects with 10A AC current, the mains voltage measured by the inverter drops by 4-5v. This voltage elevation at the inverter is consistent with the mains cable size 1.5mm, 11 meter cable length to the mains connection, and 10A current.
- Our mains voltage is higher in the afternoon than in the morning - and the disconnects occur only in the afternoon.
- The AC voltage at the inverter will be more on sunny days as the AC current from the inverter, and therefore also the voltage elevation, will be higher - and the disconnects only happen on sunny days.