The fault started with errro code 51 when i check its overcurrent protection or surge

The inverter will run for 30mins the comes with error 51 and then shuts down, then it will need another reset same thing happens again

this inverter if 4 years old

 

When i removed to send for repairs it eventual came with error 09 wihich says DC soft failed error 09.

 

please can anyone help

I have had the same errors (and others) on a 5kva clone (dead now after 4 years) and I'm pretty sure it is down to the location being too hot and also running 72 cell panels in 3S configuration on a 145V max SCC. Not sure if you have the low voltage model and what you panel configuration is? Hope it helps.