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So the enginerr just left the house after testing and replacing a few things.

  1. All firmwares updated
  2. 1 shunt remoewd and 2 new wired in as they now belive the shunt was faulty and cutting off the PV array due to overheat, asked them to install one each string thsi time and move them lower in the attic to a cooler area which they did. Model Projoy PEFS-EL55-4
  3. All wiring and connections checked inclduing all of clamps which there are 3, 2 for th eedi and one for the battery system allocated in my CU, They all checked out and were correctly installed. He also confirmed gauge and lengths for me... inverter to CU 6mm at 12M length, Cu to Meter 16mm approx 7 M Length, DC strings to Inverter 4mm at 7 M Length, not posisble to check Meter to Transformer as it is sleeved.
  4. All EPM Backflow and bettery mode setting checked and were all correct.
They are almost 100% sure the shunt was the problem so lets see. Seems they cut off at 70 degrees temp inside the enclosure and frankly my loft where they were installed right at the peak could be 35 ambient on a super sunny day so perhaps that added to the power flow heating caused the shutdown. Although the manual says the shunt if it shuts down for temp must be manually reset by removal and reapplication of the AC voltage which seems to indicate power on and off cycle in the hosue which hasnt happened to date yet it had come on by itself again so who knows!!

If it is not the problem then they will adjust the country setting to increase to outbond voltage to be higher just in case it too low and our inbound is higher when exporting. Although we need to ask the network provider for permisison to do this but they always say yes if told why.

He did mention there is a fault code associated with grid voltage too high and it hasnt thrown that code ever OV-OG or something so he doesnt think that is the issue.


Thank you for the update. If it alright with you I will log in every so often and observe the system? - the next very sunny day here (maybe where you are too) is tomorrow Sun 20 Sep 20.
Guys just to close this issue the movemmeg of the fireman switch shunts lower in my loft and the installation of one on each string seems to have solved the issue.

Appears they were exceeding their operating temp and shutting off on sunny days due to heat trapped in the loft.

Wont know 100% until nect summer but so far looks good.

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