FoxESS
SW Bus Vol Fault
DC Bus Voltage Out of Range (Software)
Internal DC bus voltage outside permitted window, detected by software. Occurs on H1(G2) after DC-side transients.
Common causes
DC input voltage spike or dropBattery voltage out of rangePV string transient over-voltageLoose DC connection causing voltage bounce
What to check
STEP 1
Power cycle (AC off, DC off, wait 5 min, restore). Confirm DC input is within MPPT range (80-550 V) before restarting
STEP 2
Check battery voltage is within range (H1-G2: 80-480 V). Check all DC terminal connections are tight
Escalate if
Fault returns at normal voltages — internal hardware fault, escalate to Fox ESS UK: service.uk@fox-ess.com
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