Problem: Fronius Symo 15.0-3-M stopped functioning.
Status: Fronius Reporting ERROR 453
Grid Voltage and Power Module Discrepancy
3x Quattro 10KVA
1x Symo 15KVA AC-Coupled on Quattros AC-out
We have tested loop impedance:
L1 Quattro 5.0Ohms
L2 Quattro 4.8Ohms
L3 Quattro 0.75Ohms.
We are concerned that the difference in loop impedance may be causing the malfunction of the Fronius SYMO. We are also concerned that while replacing the SYMO may provide a temporary resolution, the difference in loop impedance may cause an eventual failure in the new SYMO.
It is to be noted that the L3 Quattro was replaced within the last year.
L1 and L2 Quattros were purchased and installed around 2015.
Your expert knowledge, comments, or advice is appreciated,