Applicable Systems
Sunny Boy
Symptoms
PV strings bridged. The inverter has detected that the positive and negative PV string inputs are bridged orshorted together.
Possible Causes
- PV string positive and negative cables shorted at combiner box
- PV connector (MC4) cross-connected between string positive and negative
- PV module internal fault causing string positive to negative short
- Inverter input bridge detection circuit fault
Troubleshooting Steps
- Step 1: Check the equipment status and fault indicators to confirm the active fault code
Fault indicator or HMI displays code 4011 as active - Step 2: Verify all electrical connections, wiring harnesses, and connector seating
All connections secure, no corrosion, loose pins, or damaged wires - Step 3: Check the system diagnostic buffer or event log for detailed fault information
Diagnostic buffer shows the specific fault cause and timestamp - Step 4: Verify power supply stability and environmental conditions
Power supply stable, environment within specifications - Step 5: Restart the equipment or power-cycle the control system
Equipment restarts and enters normal operating state - Step 6: Contact manufacturer support if the fault persists after all checks
Support provides specific troubleshooting guidance
How to Reset
To reset: 1) Identify and fix the root cause described in the fault symptoms. 2) Press RESET on the HMI or controller, or power-cycle the equipment. 3) If the fault recurs, contact manufacturer service. Caution: Document the fault code and context before resetting.
Frequently Asked Questions
- Q: What does fault code 4011 mean on the SMA Sunny Boy?
Fault 4011 on the SMA Sunny Boy indicates: PV strings bridged. The inverter has detected that the positive and negative PV string inputs are bridged or shorted together. Refer to the equipment manual and manufacturer support for specific troubleshooting steps.
- Q: Can I continue operating the equipment with fault 4011 active?
No. The equipment has detected a fault condition and has taken protective action (typically stopping or derating). Continuing to operate without fixing the root cause may cause further damage. Always investigate and fix the fault before resuming operation.
Source: SMA Sunny Boy Inverter Installation and Operation Manual, SMA Official Documentation
Category: PLC & VFD