Growatt
THOR-105

Over-Voltage on Phase L1

Supply voltage on phase L1 exceeds the permitted maximum (275V protection threshold). LCD shows 105.

Grid voltage persistently highPV export causing voltage rise on local supplyLong supply cable with high impedance allowing voltage rise from reverse current
STEP 1
Measure supply voltage at the charger input terminal. UK standard is 230V ±10% (207–253V). Anything above 253V is a G98 exceedance
STEP 2
Check if the issue correlates with high PV generation periods. If yes — voltage rise from export. Review Growatt inverter export limit settings. If persistent above 253V at all times — notify DNO
Voltage consistently above 275V — DNO supply issue, notify formally
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