I have a gx controlled Quattro installed. Two mppts with ve direct. And Blue Nova racpower series lithium pack.
Everything was running fine. Then client mentioned that his alarm system ups beeps sometimes.
I checked the advanced graphs and saw AC output current drops below zero a few times a day. Very short period as not to even power down the other appliances.
The system is ESS controlled and all units have been updated to newest firmware versions.
The output voltage is also quite high at aroun 245V sometimes.
What else can I check?