QR1 The PV power output is insufficient, yet the PV array shows no fault
How was it established that there were no faults? Did you measure this? Are any discolourations visible on the modules?
How is the module array wired? In parallel or in series? How many strings are there? If they are in parallel, are the strings protected by fuses?
What do your connections look like? Are there any abnormalities (odour, discolouration, water ingress, corrosion)?
An identical system is located very close by at the same site; we had the installer swap the MPPT controllers between the two systems: the unit that had originally been working also produces output on the faulty system, whereas the reverse swap did not provide a conclusive result.
That’s a good reason to test the system!
Hopefully the cause was a one-off event, such as lightning damage.
I’ve had some measurements taken, and the results so far are quite promising; everything points to the MPPT controller being faulty. In all my years of selling equipment and carrying out installations, I’ve never come across a fault like this, and I’d like to investigate it further. I carried out an update, albeit without much confidence, but it didn’t fix the problem.
Thank you for your contribution.