Not having a good weekend!!

[edexlab]

+1 for checking the ac plug! On the smaller sma's it's neutral in terminal 1 line in terminal 2 and earth in the earth terminal I beleive

Its a shame they don't use the same AC plug as the larger inverters , much more clearly identified, on the smaller ones I always have to double check

 

[edexlab]

Also its not a bad idea to check AC voltage and watch it for a while see if it varies, I had a job a few years ago (non pv) and the voltage was all over the place the bloke was complaining of shocks from his sink ,when checked it was fine ,no volts but kept testers on it for a while and it registered below 175v and up to 280v turned out there was a problem with transformer (TT)
its possible that this could be happening and its too unstable for the inverter , but check everything again

 

[mmccx]

With the above scenario I believe the inverter would turn on but shOw the appropriate error code. Would still be worth a check tho

 

[SRE]

DC polarity !!!!! Problem solved and thanks very, very much to everyone who has helped. We've now got a great troubleshooting guide for when we're onsite.

 

[Markc]

DC polarity !!!!! Problem solved and thanks very, very much to everyone who has helped. We've now got a great troubleshooting guide for when we're onsite.

Glad to got it going.